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Polyhedron (v.29, #2)

prelims, contents pages (pp. iii-xii).

Syntheses, characterization, and luminescent properties of four alkaline earth metal–organic frameworks based on two similar N-containing carboxylates by You-Cun Chen; Kuai-Bing Wang; Yan Wang (pp. 669-674).
Two alkaline earth metal and two similar N-containing carboxylates compared with each other to investigate the effect of metal ions and organic ligands on the structure. The result shows the different metal ions can result in same or different frameworks.Four coordination polymers {[Ca(3-pa)2(H2O)2]·3H2O} (1), {[Sr(3-pa)2(H2O)2]·3H2O} (2), {[Ca(4-pa)2(H2O)4]} (3) and {[Sr(4-pa)(H2O)6]·[4-pa]} (4), (3-pa=pyridine-3-carboxylate, 4-pa=pyridine-4-carboxylate) have been synthesized and structurally characterized. Lots of noncovalent interactions were found in the four compounds, aiding the formation of high-dimensional architectures from the low-dimensional structures. Complex1 and2 feature similar 1-D chain structures, which adopt face-to-face orientation to form an interesting 2-D network with pipe-like motif. Chain-like water clusters consisting of infinite tetragonal unit are trapped and stabled in the vacuums of the pipelines. The 2-D sheets are further connected into 3-D architecture by noncovalent interactions. Complex3 has a discrete mononuclear structure, which is further connected into a 3-D framework by hydrogen bonds and π ···π interactions. In complex4, the zigzag-like chain structure units are parallel to each other and pack in ABAB mode to give rise to a 2-D network, which is stabled by π···π stacking and hydrogen bonds. The counteranions in4 are hosted between the nets and act as “glue” linking the 2-D networks into a 3-D architecture. In addition, the photoluminescence properties of the compounds have been investigated.

Keywords: Water cluster; Alkaline earth metal complex; Photoluminescent property


Synthesis and properties of axially-phenoxycyclotriphosphazenyl substituted silicon phthalocyanine by Bünyemin Çoşut; Serkan Yeşilot; Mahmut Durmuş; Adem Kılıç; Vefa Ahsen (pp. 675-682).
In this work was shown that synthesis and characterization of axially-phenoxycyclotriphosphazenyl substituted silicon phthalocyanine. The photophysical (fluorescence quantum yield and lifetime) and photochemical (singlet oxygen generation and photodegradation quantum yield) properties of this novel compound has been investigated in DMSO solution.An hydroxyl substituted hexa(phenoxy)cyclotriphosphazene (3) is reacted with silicon phthalocyanine (4), SiPc(Cl)2, to give an axially-disubstituted phenoxycyclotriphosphazenyl silicon phthalocyanine (5). In this study, an axially phosphazene substituted phthalocyanine complex synthesized at the first time. Newly synthesized silicon phthalocyanine complex has been fully characterized by elemental analysis, ESI mass spectrometry, FT-IR,1H,13C and31P NMR spectroscopy. Photophysical (fluorescence quantum yield and lifetime) and photochemical (singlet oxygen generation and photodegradation quantum yield) properties of complex5 are reported in DMSO. The fluorescence quenching behaviour of this complex by 1,4-benzoquinone (BQ) is also reported in DMSO.

Keywords: Silicon phthalocyanine; Cyclotriphosphazene; Fluorescence; Singlet oxygen; Quantum yield


Nickel(II) derivatives of N-benzyliminodiacetate(2−) ligands, with and without imidazole: Synthesis, crystal structure and properties by D.K. Patel; D. Choquesillo-Lazarte; J.M. González-Pérez; A. Domínguez-Martín; A. Matilla-Hernandez; A. Castiñeiras; J. Niclós-Gutiérrez (pp. 683-690).
The structures of the binary molecular compounds [Ni(Chel)(H2O)3nH2O ( n=0 or 1) and the salts [Ni(Him)6][Ni(Chel)2]·4H2O are reported (Chel=N-( p-methylbenzyl) or N-( p-methoxybenzyl)iminodiacetate(2−) ligands; Him=imidazole). The ternary compounds [Ni(Chel)(Him)3nH2O were not obtained. These facts are related to the nature of the non-coordinating N-arm of Chel and the octahedral Ni(II) centre.In an attempt to prepare binary and ternary compounds, we have obtained two molecular complexes [Ni(MEBIDA or MOBIDA)(H2O)3nH2O ( n=0 or 1) and two iso-type salts [Ni(Him)6][Ni(MEBIDA or MOBIDA)2]·4H2O [MEBIDA=N-( p-methylbenzyl)iminodiacetate(2−) and MOBIDA=N-( p-methoxybenzyl)iminodiacetate(2−) ligands, Him=imidazole]. Our results are discussed with regard to related copper(II) and nickel(II) compounds. The reasons for which these chelating ligands produce nickel(II) salts instead of ternary compounds remain unclear since other iminodiacetate-like ligands give true ternary Ni(II) compounds with imidazole and other N-heterocyclic ligands.

Keywords: Nickel(II) complexes; Iminodiacetate; Imidazole; Crystal structure


Low temperature synthesis of metal chalcogenide nanoparticles in mesitylene by P. Christian; E. Liu (pp. 691-696).
The present paper reports new method for the synthesis of zinc and cadmium chalcogenide nanoparticles. The materials are prepared in mesitylene using phosphines, phosphine oxides or amines as capping agents. The low temperature (150°C) and low concentrations of capping agent and the use of conventional solvents make this method of particular interest for the manufacture of nanomaterials.We report a new method for the synthesis of zinc and cadmium chalcogenide nanoparticles. The materials are prepared in mesitylene using phosphines, phosphine oxides or amines as capping agents. The low temperature (150°C) and low concentrations of capping agent, and the use of conventional solvents make this method of particular interest for the manufacture of nanomaterials. Furthermore, the data reported here allow trends in reactivity to be studied and also allow the synthesis of ZnSe which is typically prepared at >250°C.

Keywords: Quantum dot; Zinc sulfide; Zinc selenide; Zinc telluride; Cadmium sulfide; Cadmium selenide; Cadmium telluride; Conventional solvent; ZnS; ZnSe; ZnTe; CdS; CdSe; CdTe


New titanium and zirconium initiators for the production of polylactide by M.D. Jones; M.G. Davidson; G. Kociok-Kohn (pp. 697-700).
The crystal structures of two novel group 4 metal complexes based in N, N′-Bis(2-hydroxybenzyl)ethylenediamine have been prepared and fully characterised via multi-nuclear NMR spectroscopy and single crystal X-ray diffraction studies. The complexes have been tested for the ROP of rac-lactide under melt conditions.Two new group 4 initiators based on N, N′-Bis(2-hydroxybenzyl)ethylenediamine have been prepared and fully characterised via multi-nuclear NMR spectroscopy and single crystal X-ray diffraction studies. The complexes have been tested for the production of polylactide. The phenolate ligand complexes to Ti(IV) to generate the β- cis isomer in the solid-state. Whereas for Zr(IV) the isolated species (regardless of stoichiometery) is a diligated complex.

Keywords: Polylactide; Titanium; Zirconium; Polyesters


Silver(I) tertiary phosphine complexes: Influence of the anion on the structural and spectroscopic properties by Muhammad Altaf; Helen Stoeckli-Evans (pp. 701-708).
Two-, three- and four-coordinate silver(I) complexes, AgX (X=CN-,PF6-, andSbF6-), with various tertiary phosphines have been synthesized and characterized by single crystal X-ray diffraction, elemental analysis, infrared spectroscopy, and13C and31P NMR spectroscopy. 1:2, 1:3, and 1:4 compounds were obtained, with a wide variety of geometries around the central silver(I) atom, including distorted tetrahedral, linear and distorted trigonal planar.Two-, three- and four-coordinate silver(I) complexes, AgX (X = CN,PF6-, andSbF6-), with triphenyl phosphine, tricyclohexyl phosphine, diphenylcyclohexyl phosphine, and dicyclohexylphenyl phosphine have been synthesised and characterised by single crystal X-ray diffraction, elemental analysis, infrared spectroscopy, and13C and31P NMR spectroscopy. From the reaction of a metal salt to phosphine ligand ratio of 1:1 the various compounds crystallize as 1:2, 1:3, and 1:4 compounds [Ag(PPh2Cy)3(CN)]·5H2O (1), [Ag(PCy3)2]·PF6 (2), [Ag(PPh3)4)]·SbF6·CHCl3 (3), [Ag(PCy3)2]·SbF6 (4), [Ag(PPh2Cy)2(C3H6O)]·SbF6 (5), and [Ag(PPhCy2)2]·SbF6.CHCl3 (6) monomers, with a wide variety of geometries around the central silver(I) atom. Compounds1 and3 have slightly distorted tetrahedral geometry around the silver(I) atom. The compounds2,4, and6 show linear geometry around the metal centre, while compound5 has a distorted trigonal planar geometry. The elemental analysis and NMR spectroscopic results are consistent with the single crystal structural analyses.

Keywords: Tertiary phosphines; Silver(I) complexes; Crystal structure; Spectroscopic studies


Water–chloride 2D-network in 4′-(2-pyridyl)-2,2′:6′,2′′-terpyridine bis-chelates of M(II) {M=Fe, Ni, Ru} by Sumanta Kumar Padhi; Rojalin Sahu; Vadivelu Manivannan (pp. 709-714).
Bis-chelates of 4′-(2-pyridyl)-2,2′:6′,2′′-terpyridine (L), having the formula [M(L)2]Cl2· xH2O {M=Ni(II), Fe(II), Ru(II) and x=8, 9, 10, respectively}, contain hydrophilic layers of a water–chloride 2D-network amalgamated between the hydrophobic layers formed by the [M(L)2]2+ ions.A triad of bis-chelates of 4′-(2-pyridyl)-2,2′:6′,2′′-terpyridine (L), with the formula [M(L)2]Cl2· xH2O, {M=Ni, Fe, Ru and x=8, 9, 10, respectively}, have been synthesized. All the three complexes crystallized in theP1¯ space group and each contain the respective iso-structural [M(L)2]2+ species, two Cl ions as well as water molecules of crystallization. The water–chloride 2D-network are amalgamated between the hydrophobic layers of [M(L)2]2+ ions. The centro-symmetric repeating unit that makes the water–chloride 2D-network is of a L5(2)5(3)8(2)4 pattern. Thermogravimetric profiles for the loss of water molecules are reported.

Keywords: Terpyridine; Iso-structural; Magnetism; 2D-network; Hydrophilic; Hydrophobic


Synthesis and characterization of N-thiophosphorylated thioureas RC(S)NHP(S)(O iPr)2 ( p-(4-imidazol-1-yl)–C6H4NH, p-NC–C6H4NH, (CH2CH–CH2)2N): Unexpected formation of o-HO–C6H4NHC(S)NHP(S)(O iPr)2 from p-NC–C6H4NHC(S)NHP(S)(O iPr)2 by Damir A. Safin; Maria G. Babashkina; Michael Bolte; Axel Klein (pp. 715-718).
Reaction of p-(4-imidazol-1-yl)–C6H4NH2, p-NC–C6H4NH2 or (CH2CH–CH2)2NH with O, O′-diisopropylthiophosphoric acid isothiocyanate ( iPrO)2P(S)NCS leads to p-(4-imidazol-1-yl)–C6H4NHC(S)NHP(S)(O iPr)2 (HLI), p-NC–C6H4NHC(S)NHP(S)(O iPr)2 (HLII) and (CH2CH–CH2)2NC(S)NHP(S)(O iPr)2 (HLIII). Recrystallization ofHLII from 96% aqueous EtOH solution leads to the formation of o-HO–C6H4NHC(S)NHP(S)(O iPr)2 (HLIV).Reaction of p-(4-imidazol-1-yl)–C6H4NH2, p-NC–C6H4NH2 or (CH2CH–CH2)2NH with O, O′-diisopropylthiophosphoric acid isothiocyanate ( iPrO)2P(S)NCS leads to p-(4-imidazol-1-yl)–C6H4NHC(S)NHP(S)(O iPr)2 (HLI), p-NC–C6H4NHC(S)NHP(S)(O iPr)2 (HLII) and (CH2CH–CH2)2NC(S)NHP(S)(O iPr)2 (HLIII). Recrystallization ofHLII from 96% aqueous EtOH solution leads to the formation of o-HO–C6H4NHC(S)NHP(S)(O iPr)2 (HLIV). The structures ofHLI–IV were investigated by1H and31P{1H} NMR spectroscopy, and microanalysis. The molecular structures ofHLI,IV were elucidated by single crystal X-ray diffraction analysis. Single crystal X-ray diffraction studies showed thatHLI,IV form both intra- and intermolecular hydrogen bonds, the latter leading to the formation of polymeric chains.

Keywords: Thiophosphorylthiourea; Crystal structure; NMR spectroscopy; Hydrogen bond


Crystal and supramolecular structures of dioxomolybdenum(VI) and dioxotungsten(VI) complexes of dihydroxybenzoic acids by Bernardo Monteiro; Luís Cunha-Silva; Sandra Gago; Jacek Klinowski; Filipe A. Almeida Paz; João Rocha; Isabel S. Gonçalves; Martyn Pillinger (pp. 719-730).
The synthesis, detailed crystallization procedures, crystal and molecular structures of five mononuclear molybdenum/tungsten complexes of 2,3- and 3,4-dihydroxybenzoic acids are described. Each structure contains only one of the three possible geometric isomers. The supramolecular hydrogen-bonded networks promoted by the complexes and co-crystallized molecular species have been examined in detail.The tetramethylammonium salts (NMe4)2[MO2(2,3-Hdhb)2]·2H2O and (NMe4)2[MO2(3,4-Hdhb)2]·6H2O (M=Mo, W; Hdhb=monoprotonated form of 2,3- or 3,4-dihydroxybenzoic acid, 2,3-H3dhb or 3,4-H3dhb) were prepared and their crystal structures determined. The structure of [Mg(H2O)6](NMe4)4[MoO2(3,4-dhb)(3,4-Hdhb)]2·13H2O, obtained by the recrystallization of (NMe4)2[MoO2(3,4-Hdhb)2] in the presence of magnesium ions, is also reported. The supramolecular interactions of the five structures are discussed in detail concerning the hydrogen bonding patterns involving complexes and water molecules of crystallization.

Keywords: Molybdenum; Tungsten; O ligands; X-ray diffraction; Hydrogen bonds; Supramolecular chemistry


DNA binding and cleavage behaviors of copper(II) complexes with amidino- O-methylurea and N-methylphenyl-amidino- O-methylurea, and their antibacterial activities by Unchulee Chaveerach; Atittaya Meenongwa; Yanee Trongpanich; Chaiyaporn Soikum; Prapansak Chaveerach (pp. 731-738).
DNA binding and cleavage properties of two copper(II) complexes with ligands derived from guanidine have been investigated by various techniques. It was found that both complexes have the potential not only to interact with DNA, but also to inhibit bacterial growth.The two designed copper(II) complexes, [Cu(L1m)2]Cl2 (1) (L1m=amidino- O-methylurea) and [Cu(L2m)2]Cl2 (2) (L2m= N-methylphenyl-amidino- O-methylurea), have been investigated for their interaction with calf thymus DNA by utilizing the absorption titration method, viscometric studies and thermal denaturation. The cleavage reaction on pBR322 DNA has been monitored by agarose gel electrophoresis. The results suggest that the two complexes can bind to DNA by non-intercalative modes and exhibit nuclease activities in which supercoiled plasmid DNA is converted to the linear form. Complex2, with an intrinsic binding constant ( Kb) of 1.16×105M−1, shows a higher binding efficiency and a better nuclease activity than complex1, with a Kb value of 5.67×104M−1. Their DNA cleavage potential can be significantly enhanced by hydrogen peroxide, indicating an oxidative cleavage process. Further examination of the antibacterial activities against Campylobacter has revealed inhibition zones of 9.0 (for1) and 14.5mm (for2), which are in agreement with their minimum inhibitory concentration (MIC) values of 1.56 and 0.78mgmL−1, respectively. The substantially better reactivity of2 results from the aromatic moieties on the side chain of the L2m ligand which act as an additional binding site.

Keywords: Amidino-; O; -alkylurea; Copper(II); DNA binding; DNA cleavage; Nuclease activity; Antibacterial


Formation and crystal structures of [(alkoxy)bis(pyridin-2-yl)methanolato- N,O,N]tin(IV) complexes by R. Alan Howie; Geraldo M. de Lima; James L. Wardell; Solange M.S.V. Wardell (pp. 739-748).
[(Alkoxy)bis(pyridin-2-yl)methanolato- N,O,N]tin(IV) complexes, have been obtained from reactions between bis(pyridin-2-yl)ketone and SnX4 or RSnX3 in alcohol solutions.Reactions of bis(pyridin-2-yl)ketone with tin tetrahalides, SnX4 (X=Cl or Br), or organotin trichlorides, RSnCl3 (R=Ph, Bu or CH2CH2CO2Me), in ROH (R=Me or Et) readily produces RObis(pyridin-2-yl)methanolato)tin complexes, [5: RO(py)2C(OSnX3)] (5: R,X=Me,Cl; Et,Cl; Et,Br) or [6: MeO(py)2C(OSnCl2R)] (R=Ph, Bu, CH2CH2CO2Me). In addition, halide exchange reaction between SnI4 and (5: R,X=Me,Cl) occurred to give (5: R,X=Me,I). The crystal structures of six tin(IV) derivatives indicated, in all cases, a monoanionic tridentate ligand, [RO(py)2C(O)- N,O,N], arranged in a fac manner about a distorted octahedral tin atom. The Sn–O and Sn–N bonds lengths do not show much variation amongst the six complexes despite the differences in the other ligands at tin.

Keywords: Mononuclear Sn(IV) complexes; Hemiketal-based ligands; N,O,N; ligands; Bis(pyridin-2-yl)ketone; Alkoxy; (; bis(pyridin-2-yl)methanolato complexes


Synthesis, characterization and spectroscopic study of riboflavin–molybdenum complex by Catherine N. Malele; Jayanta Ray; Wayne E. Jones Jr. (pp. 749-756).
A riboflavin–molybdenum [(RF)–Mo(V)] complex in powder form was synthesized and characterized by elemental analysis, UV–Vis, IR, NMR, XRD and investigated in HCl by steady state absorption and emission. XRD revealed orthorhombic cubic system for RF–Mo. Fluorescence quenching was observed for aqueous solution of RF and RF–Mo by increasing concentration of HCl.A riboflavin–molybdenum [(RF)–Mo(V)] complex in powder form was synthesized and characterized by elemental analysis, UV–Vis, IR, NMR spectroscopy and X-ray diffraction. During the synthesis of this metal complex, another metal complex [Mo2O4(H2O)6]2+ was also synthesized and characterized. The results of X-ray diffraction study have revealed an orthorhombic cubic system for the RF–Mo complex. The steady state absorption and emission studies of RF and RF–Mo in hydrochloric acid (HCl) of varying pH were investigated. The steady state absorption with RF–Mo showed distinct changes in the absorption spectra of RF after complexation. The steady state emission results, consistent with prior reports showed fluorescence quenching in the aqueous solution of both RF and RF–Mo in HCl with the proton acting as a quencher. The Stern–Volmer constant observed was 108.79 and 98.68 for RF and RF–Mo, respectively. The binding constant for RF–Mo complex was found to be 1.201×103M−1 at 298K.

Keywords: Riboflavin; Molybdenum; IR/NMR; X-ray diffraction spectra; Orthorhombic; Fluorescence quenching


Synthesis, characterization and antibacterial activity of some new complexes of Cu(II), Ni(II), VO(II), Mn(II) with Schiff base derived from 4-amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one by Tudor Rosu; Elena Pahontu; Catalin Maxim; Rodica Georgescu; Nicolae Stanica; Gabriela Laura Almajan; Aurelian Gulea (pp. 757-766).
The crystal structure of 1-phenyl-2,3-dimethyl-4-(N-3-formyl-6-methyl-chromone)-3-pyrazolin-5-one (HL) has been determined by X-ray diffraction studies, as well as the one of its copper(II) complex [CuL(OAc)]·CH3OH which contains an anionic ligand and an acetate in the coordination sphere of the metal.Coordination compounds of Cu(II), VO(II), Ni(II), and Mn(II) with the Schiff base obtained through the condensation of 4-amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one with 3-formyl-6-methyl-chromone were synthesized. The characterization of the newly formed compounds was done by1H NMR, UV–Vis, IR, ESR spectroscopy, elemental analysis and molar electric conductibility. The crystal structure of 1-phenyl-2,3-dimethyl-4-(N-3-formyl-6-methyl-chromone)-3-pyrazolin-5-one (HL) has been determined by X-ray diffraction studies, as well as the one of its copper(II) complex [CuL(OAc)]·CH3OH which contains an anionic ligand and an acetate in the coordination sphere of the metal. The single crystal X-ray structure for (HL) was analyzed for its various weak H-bonding and dimeric association.The in vitro antibacterial activity against Staphylococcus aureus var. Oxford 6538, Klebsiella pneumoniae ATCC 100131, Escherichia coli ATCC 10536, and Pseudomonas aeruginosa ATCC 9027 was studied and compared to the activity of the free ligand.

Keywords: Schiff bases; Antimicrobial activity; Metal complexes; 4-Amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one; Crystal structure; 3-Formyl-6-methyl-chromone


The roles of ligands proton affinity, π-back donation and metal fragment hardness on the Au–N bond in N-donor heterocycles gold(III) complexes by Marco Bortoluzzi; Gino Paolucci; Bruno Pitteri (pp. 767-772).
A DFT study on the Au–N interaction for some groups of N-donor heterocycles L in AuX3L complexes is reported. The π-acceptor ability of the 5-membered N-donor ligands resulted in all the cases greater than that of the 6-membered N-heterocycles. The minimum proton affinity average value for an interaction between the N-heterocycles and gold(III) has been estimated; this parameter does not depend on the electronic features of the coordinated ligands. The sensitivity of AuX3 towards ligands proton affinity has been related to the metal fragment relative hardness.A DFT study on the Au–N interaction for some groups of N-donor heterocycles L {L=pyridines (py), pyrimidines (pm), imidazoles (im), pyrazoles (pz) and isoxazoles (io)} in neutral AuX3L complexes {AuX3=AuBr3, AuCl3, trans-AuCl(CN)2, Au(CN)3} is reported. Linear relationships between the AuX3 Mulliken charge in AuX3L and the computed proton affinity (PA) of the heterocycle were found for all the considered ligands. The different slopes found on changing the N-donor species represent a measure of the π-acidity of these nitrogen ligands once coordinated to the metal centre, by the consequence a π-acceptor ability scale has been derived. The π-acceptor ability of the 5-membered N-donor ligands resulted in all the cases greater than that of the 6-membered N-heterocycles. The proton affinity average value corresponding to a zero charge of the AuX3 and L fragments in the AuX3L species has been estimated. This parameter represents the minimum PA value for the formation of a bond between the N-heterocycles and gold(III) and it does not depend on the electronic features of the coordinated ligands. The sensitivity of the AuX3 fragments towards ligands PA variations follows the order Au(CN)3< trans-AuCl(CN)233 and this last result has been explained on the basis of the metal fragments relative hardness.

Keywords: Gold; Square-planar complexes; Nitrogen ligands; Proton affinity; π-Acidity; Hardness; DFT


Construction of Cd(II) compounds with a chelating ligand 2,2′-dipyridiylamine (Hdpa): Anion effect, catalytic activities and luminescence by Byeong Kwon Park; Geun Hee Eom; Soo Hyun Kim; Han Kwak; Seung Man Yoo; Yu Jin Lee; Cheal Kim; Sung-Jin Kim; Youngmee Kim (pp. 773-786).
Six new structures of Cd(II) complexes containing Hdpa ligands have been determined, and their one-, two-, and three-dimensional structures can be produced by hydrogen bonds and π–π interactions. They catalyzed efficiently the transesterification of a variety of esters with methanol and showed the luminescent properties.Six new structures of Cd(II) complexes containing Hdpa ligands have been determined. With chloride and bromide, Cd(II) ions produce halide-bridged dinuclear units1 and2 while CdI2 produces mononuclear unit3 without halide-bridging. Cd(II) ions produce mono-Hdpa complex4 with chelating benzoate, di-Hdpa complex5 with coordinatingNO3- anion, and tri-Hdpa complexes6 and7 with non-coordinatingClO4- andBF4- anions. One-, two-, or three-dimensional structures of Cd(II)–Hdpa complexes can be produced by hydrogen bonding interactions and π–π interactions. The compounds4,5, and6 catalyzed efficiently the transesterification of a variety of esters with methanol, while1,2,3 and7 have displayed a very slow conversion. The transesterification reactivity shown by the catalyst6 is very efficient and the best among the compounds17. In addition, all compounds17 and ligand (Hdpa) have shown the similar luminescent properties at λmax=352nm which suggest that their emissions seem to be attributed to the π–π∗ intraligand fluorescence.

Keywords: 2,2′-Dipyridylamine; Anion effect; Transesterification; Luminescence; Cd(II) complexes


A novel di-iron(III) structure based on an ageless ligand by Jean-Pierre Costes; Françoise Dahan; Frédéric Dumestre; Jean-Pierre Tuchagues (pp. 787-790).
Two Schiff base ligands coordinate as chelating ligands while the third one acts as a chelating and bridging ligand, thus yielding an original true racemate high-spin dinuclear iron(III) complex (Λ–Λ and Δ–Δ pairs), as confirmed by magnetic, EPR and Mössbauer studies.Salen-type Schiff base ligands possess a N2O2 coordination site able to chelate transition metal ions. Reaction of such a ligand with FeCl3·6H2O leads to the formation of a genuine dinuclear L3Fe2 complex in which the ligand plays a double role. The structural determination confirms that each iron ion is wrapped up by a chelating tetradentate ligand while the third one ensures a bridge in between the two Fe ions and completes to six the metal coordination sphere. Such a bridge implies a non planar coordination of the chelating ligands and induces helicity around each metal ion. Crystals are true racemates made of homochiral Λ–Λ and Δ–Δ pairs. The magnetic study confirms the absence of a spin exchange interaction through the saturated diamino chain and the presence of an axial single ion zero field splitting (ZFS) D equal to −0.7cm−1. The Mössbauer spectra show a unique asymmetric quadrupole-split doublet with isomer shift values, δ, of 0.342(2), 0.438(2) and 0.450(2)mms−1, and quadrupole splittings, Δ EQ, of 0.826(4), 0.836(4) and 0.827(4)mms−1 at 293, 80 and 4.5K, respectively. These values are in agreement with a high-spin iron(III) site in a N3O3 ligand environment.

Keywords: Iron; Dimetallic complexes; Salen ligands; Coordination modes


Heteroleptic rhodium complexes containing both the dipyrrin/cyclooctadiene ligands and application of [(η4-C8H12)Rh(4-pyrdpm)] in the construction of homo-/hetero-bimetallic complexes by Mahendra Yadav; Prashant Kumar; Daya Shankar Pandey (pp. 791-800).
First examples of heteroleptic rhodium(I) complexes containing both the dipyrrin and η4 -cyclooctadiene groups have been synthesized. The complex [(η4-C8H12)Rh(4-pyrdpm)] have been employed as a synthon in the construction of homo/hetero-bimetallic complexes.Heteroleptic rhodium(I) complexes with the general formulations [(η4-C8H12)Rh(L)] [η4-C8H12=1,5-cyclooctadiene; L=5-(4-cyanophenyl)dipyrromethene, cydpm; 5-(4-nitrophenyl)dipyrromethene, ndpm; and 5-(4-benzyloxyphenyl)dipyrromethene, bdpm; 5-(4-pyridyl)dipyrromethene, 4-pyrdpm; 5-(3-pyridyl)dipyrromethene, 3-pyrdpm] have been synthesized. The complex [(η4-C8H12)Rh(4-pyrdpm)] have been used as a synthon in the construction of homo-bimetallic complex [(η4-C8H12)Rh(μ-4-pyrdpm)Rh(η5-C5Me5)Cl2] and hetero-bimetallic complexes [(η4-C8H12)Rh(μ-4-pyrdpm)Ir(η5-C5Me5)Cl2], [(η4-C8H12)Rh(μ-4-pyrdpm)Ru(η6-C10H14)Cl2] and [(η4-C8H12)Rh(μ-4-pyrdpm)Ru(η6-C6H6)Cl2]. Resulting complexes have been characterized by elemental analyses and spectral studies. Molecular structures of the representative mononuclear complexes [(η4-C8H12)Rh(ndpm)] and [(η4-C8H12)Rh(4-pyrdpm)] have been authenticated crystallographically.

Keywords: Rhodium; Heteroleptic; Dipyrrins; Homo-/hetero-bimetallic complexes


Syntheses and characterization of different zinc(II) oxide nano-structures from direct thermal decomposition of 1D coordination polymers by Fahime Bigdeli; Ali Morsali; Pascal Retailleau (pp. 801-806).
Three zinc(II) nitrite coordination polymers, [Zn(4-bpdb)(NO2)2] n (1), {[Zn (3-bpdb) (NO2)]·0.5H2O} n (2) and [Zn(3-bpdh)(NO2)2] n (3), 4-bpdb=1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene, 3-bpdb=1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene and 3-bpdh=2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene} were prepared and characterized by elemental analyses and IR spectroscopy. Compound3 was structurally characterized by single-crystal X-ray diffraction and is one-dimensional polymer with coordination environments of distorted octahedral, ZnN2O4.Three zinc(II) nitrite coordination polymers, [Zn(4-bpdb)(NO2)2] n (1), {[Zn(3-bpdb)(NO2)]·0.5H2O} n (2) and [Zn(3-bpdh)(NO2)2] n (3), 4-bpdb = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene, 3-bpdb=1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene and 3-bpdh=2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene} were prepared and characterized by elemental analyses and IR spectroscopy. Compound3 was structurally characterized by single-crystal X-ray diffraction and is one-dimensional polymer with coordination environments of distorted octahedral, ZnN2O4. The thermal stabilities of compounds1–3 were studied by thermal gravimetric (TG) and differential thermal analyses (DTA). Direct calcination of the compounds1–3 at 600°C under air atmospheres yields different morphologies of nano-sized ZnO.

Keywords: Zinc(II) oxide; Nano-structure; Coordination polymer; Zinc(II) nitrite


Metal-dependent assembly of a tetranuclear copper(II) complex versus a 1D chain coordination polymer of cobalt(III) complex with N2O2-chelating Schiff-base ligand: Synthesis, characterization and crystal structures by Aliakbar Dehno Khalaji; Hassan Hadadzadeh; Karla Fejfarova; Michal Dusek (pp. 807-812).
From the direct reaction of sal2hn with Cu(NO3)2·3H2O or Co(NO3)2·6H2O at the presence a large excess of NaN3, tetranuclear Cu(II) complex [Cu4( μ-sal2hn)2( μ1,1-N3)2(N3)2] (1) and 1D coordination polymer of Co(III) complex {Na[Co( μ-sal2hn)( μ1,1-N3)2]} n (2) were prepared. Single-crystal X-ray analyses revealed that in complex1 the copper(II) ions are bridged alternately by end-on (EO) azido and phenoxo-sal2hn ligands, while in complex2 the cobalt(III) and sodium ions are bridged alternately by end-on (EO) azido and phenoxo-sal2hn ligands.By changing metal ions in the presence of N2O2-chelating Schiff-base ligand sal2hn [sal2hn= N,N′-bis(salicylidene)-1,2-diaminocyclohexane] and a large excess of NaN3 (reagent ratios (metal:L:N3-)=2:1:8), tetranuclear copper(II) complex [Cu4( μ-sal2hn)2( μ1,1-N3)2(N3)2] (1) and 1D chain coordination polymer of cobalt(III) complex {Na[Co( μ-sal2hn)( μ1,1-N3)(N3)(H2O)( μ-O)} n (2) have been successfully obtained. Single-crystal X-ray analyses revealed that in complex1 the copper(II) ions are bridged alternately by end-on (EO) azido and phenoxo-sal2hn ligands, while in complex2 the cobalt(III) and sodium ions are bridged alternately by end-on (EO) azido and phenoxo-sal2hn ligands. Complex1 crystallizes in the monoclinic system, space group P21/ n, with a=11.6283(5)Å, b=19.5997(8)Å, c=9.1531(4)Å, β=90.540(6)°, V=2086.00(15)Å3, and Z=2, while complex2 crystallizes in the monoclinic system, space group C21/ c, with a=21.1473(5)Å, b=14.0604(3)Å, c=15.0452(6)Å, β=106.064(3)°, V=4298.9(2)Å3, and Z=8.

Keywords: N; 2; O; 2; -chelating; Tetranuclear; Copper(II); 1D Chain; Cobalt(III); Single-crystal; Square pyramidal; Octahedral


Quinolin-2(1 H)-one-triazole derived Schiff bases and their Cu(II) and Zn(II) complexes: Possible new therapeutic agents by Bernadette S. Creaven; Michael Devereux; Agnieszka Foltyn; Siobhán McClean; Georgina Rosair; Venkat Reddy Thangella; Maureen Walsh (pp. 813-822).
The condensation of 4-amino-1,2,4-triazole with N-substituted-3-formyl-4-hydroxyquinolin-2-(1 H)-one derivatives has lead to the synthesis of a new series of quinolin-2(1 H)-one-triazole derived Schiff base ligands. Cu(II) and Zn(II) complexes of these ligands were also prepared. X-ray crystallography confirmed that the geometry at the metal centre was octahedral and that the Schiff base acted as a bidentate ligand coordinating to the metal(II) ion through the deprotonated oxygen and azomethine nitrogen atoms. All of the compounds were investigated for their antimicrobial activities against a fungal strain, Candida albicans, and against Gram-positive and Gram-negative bacteria.The condensation of 4-amino-1,2,4-triazole with N-substituted-3-formyl-4-hydroxyquinolin-2-(1 H)-one derivatives has lead to the synthesis of a new series of quinolin-2(1 H)-one-triazole derived Schiff base ligands (13). Cu(II) and Zn(II) complexes (1a3a and1b3b, respectively) of these ligands were also prepared. The complexes were characterised by standard techniques and for two of the complexes X-ray crystallography confirmed that the geometry at the metal centre was octahedral in both cases and that the Schiff base acted as a bidentate ligand coordinating to the metal(II) ion through the deprotonated oxygen and azomethine nitrogen atoms. All of the compounds were investigated for their antimicrobial activities against a fungal strain, Candida albicans, and against Gram-positive and Gram-negative bacteria. The compounds were found to be active against C. albicans but inactive against Staphylococcus aureus and Escherichia coli.

Keywords: Quinolin-2(1; H; )-one; 4-Amino-1,2,4-triazole; Schiff bases; Metal(II) complexes; Biological activity; X-ray structures


Keen competition between electrostatic and argentophilic interactions in the formation and behavior of molecular rings by Cho Rong Kim; Jungmin Ahn; Tae Hwan Noh; Ok-Sang Jung (pp. 823-826).
Slow diffusion of AgX (X=NO3 and CF3SO3) with bis(nicotinoyl)-4,4′-(9-fluorenylidene)diphenolate (L) yields discrete cyclodimeric rings and linked cyclodimeric rings, respectively, via the competition between the inter-ring argentophilic (Ag···Ag) interaction and the electrostatic interaction between Ag(I) and its anion.The macrocyclic structures and behavior on the reaction of AgX (X=NO3 and CF3SO3) with bis(nicotinoyl)-4,4′-(9-fluorenylidene)diphenolates (L) have been carried out. Discrete oblong rings and linked rings were constructed via the keen competition between the inter-ring argentophilic (Ag···Ag) interaction and the electrostatic interaction between Ag(I) and its anion, and the interconversion of the two species was attempted by means of anion exchange.

Keywords: Anion effects; Argentophilic interaction; Electrostatic interaction; Molecular ring; Silver complexes


Synthesis of two new thioesters bearing ferrocene: Vibrational characterization and ab initio calculations. X-ray crystal structure of S-(2-methoxyphenyl)ferrocenecarbothioate by Isabel C. Henao Castañeda; Carlos O. Della Védova; Oscar E. Piro; Nils Metzler-Nolte; Jorge L. Jios (pp. 827-832).
Two new ferrocenecarbothioates (I) and (II) are fully analyzed using X-ray diffraction, vibrational data and theoretical calculations. The combined experimental and theoretical approach allows a consistent assignment for most of the fundamental modes. The predominance of the syn conformation is the relevant structural property of these molecules.Structural and conformational properties of S-benzyl ferrocenecarbothioate (I) and S-(2-methoxyphenyl) ferrocenecarbothioate (II) are analyzed using data obtained from X-ray diffraction, vibrational data and theoretical calculations. According to chemical quantum calculations, the synperiplanar and antiperiplanar forms are found as the first and second more stable conformations, respectively, for the title compounds. The geometric parameters and normal modes of vibration were calculated using a density functional theory method (B3LYP) and the 6-31+G∗∗ basis set for all atoms except for iron. For this atom the calculations were carried out with the Lanl2dz basis set. The calculated parameters are in good agreement with the corresponding X-ray diffraction values. The combined experimental and theoretical approach allows a consistent assignment for most of the fundamental modes.

Keywords: Metallocenes; Ferrocenecarbothioates; X-ray single crystal analysis; Vibrational analysis; Conformation analysis; Density functional calculations


Synthetic, structural and spectroscopic studies of copper(II) complexes derived from the combination of the succinamate(−1) ligand with aromatic N,N′-chelates by Katerina N. Lazarou; Iordanis Chadjistamatis; Aris Terzis; Spyros P. Perlepes; Catherine P. Raptopoulou (pp. 833-840).
The use of succinamic acid (H2sucm) in CuX2· yH2O (X=NO3-, y=3; X=Cl, y=0)/N,N′-donor (bpy, phen, dmbpy) reaction mixtures yields dinuclear complexes and 1D coordination polymers. The coordinative versatility of the succinamate(−1) ligand is reflected on the three different ligation modes observed, while its hydrogen bonding ability gives rise to interesting 1D, 2D and 3D supramolecular structures.The use of succinamic acid (H2sucm)/N,N′-chelate (2,2′-bipyridine, bpy; 4,4′-dimethyl-2,2′-bipyridine, dmbpy; 1,10-phenanthroline, phen) ‘ligand blends’ in CuX2· yH2O (X=NO3, y=3; X=Cl, y=0) chemistry has yielded the new complexes [Cu2(Hsucm)3(bpy)2](NO3)·0.5MeOH (1·0.5MeOH), [Cu2(Hsucm)(OH)Cl(bpy)2](OH)·3.6H2O (5·3.6H2O) and [Cu2(Hsucm)2Cl2(phen)2] (6). The succinamate(−1) ion behaves as a carboxylate ligand and exists in two different coordination modes in the structures of the above complexes, i.e., the common syn, syn μ2OO′ in1,5 and6, and the μ22 OO′ in1. The primary amide group of Hsucm remains uncoordinated and participates in intermolecular hydrogen bonding interactions leading to 1D, 2D and 3D networks. Characteristic IR bands of the complexes are discussed in terms of the known structures and the coordination modes of the Hsucm ligands.

Keywords: Copper(II) complexes; Crystal structures; IR spectra; N,N′-chelates; Succinamate(−1) complexes


Synthesis, crystal structure and reactivity of a new pentacoordinated chiral dioxomolybdenum(VI) complex by M.R. Pedrosa; J. Escribano; R. Aguado; R. Sanz; V. Díez; F.J. Arnáiz (pp. 841-849).
The novel tridentate chiral ligand 2,6-bis{[(1 R,2 S,4 R)-2-hydroxy-1,3,3-trimethyl-bicyclo[2.2.1]hept-2-yl]}pyridine (1) was readily prepared by reaction of 2,6-dilithiopyridine with ( R)-(−)-fenchone. Reaction of1 with [MoO2(acac)2] resulted in the formation of the new metal-oxo five-coordinated complex [MoO2(ONO)] (2) [ONO=(1 – 2H)]. The reactivity of2 has been studied and the derivatives [MoS2(ONO)] (3) and [MoO(O2)(ONO)] (4) were prepared. The compounds1–4 have been characterised by1H and13C{1H} NMR, microanalysis and IR spectroscopy. Furthermore, the molecular structures of1 and2 have been determined by single-crystal X-ray diffraction. The behaviour of2 as catalyst in oxotransfer and in nucleophilic substitution of propargylic alcohols reactions has been tested.The novel tridentate chiral ligand 2,6-bis{[(1 R,2 S,4 R)-2-hydroxy-1,3,3-trimethyl-bicyclo[2.2.1]hept-2-yl]}pyridine (1) was readily prepared by reaction of 2,6-dilithiopyridine with ( R)-(−)-fenchone. Reaction of1 with [MoO2(acac)2] resulted in the formation of the new metal-oxo five-coordinated complex [MoO2(ONO)] (2) [ONO=(1 – 2H)]. The reactivity of2 has been studied and the derivatives [MoS2(ONO)] (3) and [MoO(O2)(ONO)] (4) were prepared. The compounds14 have been characterised by1H and13C{1H} NMR, microanalysis and IR spectroscopy. Furthermore, the molecular structures of1 and2 have been determined by single-crystal X-ray diffraction. The behaviour of2 as catalyst in oxotransfer and in nucleophilic substitution of propargylic alcohols reactions has been tested.

Keywords: Molybdenum; Chiral ligand; Oxo ligands; O,N,O-ligands; Tridentate ligands


Mn(II) and Cd(II) macrocyclic Schiff base complexes with a single pendant coordinating 2-pyridylmethyl arm: Synthesis, X-ray crystal structure and NMR studies by Reza Golbedaghi; Sadegh Salehzadeh; Hassan Keypour; Allan G. Blackman (pp. 850-856).
Six new macrocyclic Schiff base complexes were prepared by the template condensation of two tripodal ligands and with 2-[2-(2-formyl phenoxy)ethoxy] benzaldehyde and 2-[3-(2-formyl phenoxy)propoxy]benzaldehyde in the presence of Cd(NO3)·4H2O or MnCl2 in equimolar ratios. The resulting compounds were characterized by IR spectroscopy, elemental analysis and mass spectrometry in all cases and by X-ray and NMR in the case of all Cd(II) complexes.The cyclocondensation reaction of N-(2-pyridylmethyl)-N-(2-aminoethyl)-1,2-diaminoethane, L22py, with both 2-[2-(2-formyl phenoxy)ethoxy] benzaldehyde and 2-[3-(2-formyl phenoxy)propoxy]benzaldehyde, and reaction of N-(2-pyridylmethyl)-N-(2-aminoethyl)-1,3-diaminopropane, L33py, with 2-[2-(2-formyl phenoxy)ethoxy] benzaldehyde in the presence of equimolar amounts of Cd(II) or Mn(II) metal ions is reported. The resulting compounds [CdL1Cl](ClO4)·1/2CH3CN (1), [MnL1Cl](ClO4) (2), [CdL2(NO3)](ClO4)·CH3CN (3), [MnL2Cl]ClO4 (4), [CdL3Cl](ClO4)·H2O (5) and [MnL3Cl]ClO4 (6) were characterized by IR spectroscopy, elemental analysis and mass spectrometry in all cases and by X-ray and NMR in the case of the Cd(II) complexes. X-ray single crystal structure analysis of a selected single crystal of compound (1) showed that it contains two cations (A) and (B), [CdL1Cl]+, with similar N4OCl donor sets. In contrast, the results of microanalysis, NMR and mass spectra showed that in the bulk sample, there are two different cations [CdL1Cl]+ and [CdL1(NO3)]+ in the ratio of 4–1, respectively. X-ray crystal structure determination of other cadmium complexes, (3) and (5), confirmed that in addition to the expected macrocylic ligand with a N4O2 donor set, theNO3- and Cl anions are coordinated to the central metal ion, respectively.

Keywords: Template condensation; Macrocyclic Schiff base ligands; Cadmium complex; Manganese complex; Pendant


Spectroscopy and photoredox properties of soluble platinum(II) alkynyl complexes by Akram Hijazi; Mathieu E. Walther; Céline Besnard; Oliver S. Wenger (pp. 857-863).
A series of highly soluble platinum(II) alkynyl complexes with terdentate π-acceptor ligands was synthesized and investigated by optical spectroscopic and electrochemical means. Some of the new complexes are identified as viable alternatives to previously explored but poorly soluble platinum alkynyls that find use as sensitizers for photoredox reactions.Six complexes of platinum(II) with a terdentate π-acceptor ligand, 2,6-( N-( n-hexyl)benzimidazol-2′-yl)pyridine), and different ethynylbenzene ligands were synthesized and investigated by means of optical absorption, luminescence, and time-resolved emission spectroscopy. These complexes display similar photophysical and electrochemical properties as previously investigated analogs with the 2,2′:6′,2″-terpyridine ligand. The energy of the luminescence band maximum is a function of the nature of the chemical substituents attached to the ethynylbenzene ligand, luminescence intensities and lifetimes correlate with the luminescence wavelength according to the energy-gap law. The emissive excited states of some of these complexes are quenched reductively with efficiencies near the diffusion-controlled limit, even for moderate electron donors such as phenothiazine or triphenylamine. A complex with a dimethylamine substituent attached to the ethynylbenzene ligand exhibits photophysical properties that are strongly dependent on the protonation state of the amine. A dimer complex with a diethynyl-substituted xanthene bridging ligand displays absorption and emission behavior that is essentially identical to that of some of the monomeric platinum complexes investigated in this work. Short Pt(II)–Pt(II) contacts are only observed in the crystal structure of a precursor complex. A key feature of the new complexes is their good solubility in common organic solvents, thanks to the presence of two hexyl chains that are attached to the terdentate ligands.

Keywords: Platinum; Absorption; Luminescence; Photoredox chemistry; Photosensitizer


Evaluation of the antimicrobial activity of some chloro complexes of imidazole-2-carbaldehyde semicarbazone: X-ray crystal structure of cis-NiCl2(H2L)(H2O) by María C. Rodríguez-Argüelles; Sandra Mosquera-Vázquez; Jesús Sanmartín-Matalobos; Ana M. García-Deibe; Corrado Pelizzi; Franca Zani (pp. 864-870).
Some first row transition metal(II) complexes of the general type MCl2(H2L)(H2O) where M=NiII or CuII, and MCl2(H2L)2·0.5(H2O or EtOH) where M=CoII or ZnII, and H2L=imidazole-2-carbaldehyde semicarbazone, have been synthesised, characterised and microbiologically tested.Some first row transition metal(II) complexes of imidazole-2-carbaldehyde semicarbazone (H2L) have been synthesised and characterised. Single crystal X-ray diffraction studies have revealed the molecular structure of the neutral complex NiCl2(H2L)(H2O). This latter complex shows a pseudo-octahedral geometry, with both chloride ions displaying a cis disposition. The asymmetry of this complex allows the formation of two enantiomers in the racemic crystal structure. The non-deprotonated semicarbazone ligand behaves as an N,N,O-donor, through the imidazole and imine N atoms and the Oketo atom. The coordinative behaviour of H2L in CuCl2(H2L)(H2O), ZnCl2(H2L)2·0.5EtOH and CoCl2(H2L)2·0.5H2O is reported as only N,O-donor. The antimicrobial activity of the semicarbazone ligand and its metal complexes has been tested against some representative bacteria and fungi. A moderate inhibitory activity of the cobalt complex was detected towards the assayed phytopathogenic fungi Alternaria tenuis and Sclerotinia minor (MIC 50μg/mL).

Keywords: Imidazole; Semicarbazone; Zinc; Copper; Nickel; Cobalt; Antimicrobial activity


Cobalt complexes of a selenium diimide and a tellurium diimide dimer by Maarit Risto; Jari Konu; Raija Oilunkaniemi; Risto S. Laitinen; Tristram Chivers (pp. 871-875).
[CoCl2{ N, N′-Te2(NtBu)4}] (1) was obtained in good yields by the reaction of equimolar amounts of (tBu)NTe(μ-NtBu)2TeN(tBu) and CoCl2 in toluene under an argon atmosphere. The related reaction of Se(NtBu)2 and CoCl2 affords a green product that upon recrystallization from thf produces the ion-separated complex [Co2(μ-Cl)3{ N, N′-Se(NtBu)2}2(thf)2][CoCl3{NH2(tBu)}]·1½thf (2·1½thf).[CoCl2{ N, N′-Te2(NtBu)4}] (1) was obtained in good yields by the reaction of equimolar amounts of (tBu)NTe(μ-NtBu)2TeN(tBu) and CoCl2 in toluene under an argon atmosphere. The crystal structure of1·CH2Cl2 showed that the dimeric tellurium diimide ligand is N, N′-chelated to cobalt. The related reaction of Se(NtBu)2 and CoCl2 affords a green product tentatively identified as a 1:1 adduct [CoCl2{ N, N′-Se(NtBu)2}] (CHN analysis). However, recrystallization from thf produces the ion-separated complex [Co2(μ-Cl)3{ N, N′-Se(NtBu)2}2(thf)2][CoCl3{NH2(tBu)}]·1½thf (2·1½thf), in which the monomeric selenium diimide ligand is N, N′-chelated to cobalt in the cation. A pathway for the formation of2 from [CoCl2{ N, N′-Se(NtBu)2}] in thf is proposed.

Keywords: Tellurium diimide dimer; Selenium diimide; Cobalt complexes; X-ray crystallography; 1; H NMR spectroscopy


Rhenium(I) and technetium(I) fac-M(NSO)(CO)3 (M=Re,99mTc) tricarbonyl complexes, with a tridentate NSO bifunctional agent: Synthesis, structural characterization, and radiochemistry by Dionysia Papagiannopoulou; George Makris; Charalambos Tsoukalas; Catherine P. Raptopoulou; Aris Terzis; Maria Pelecanou; Ioannis Pirmettis; Minas S. Papadopoulos (pp. 876-880).
The synthesis and characterization of the fac-[Μ(NSO)(CO)3] complexes, where M=Re or99mTc and NSO is a tridentate bifunctional chelating agent, 3-(carboxymethylthio)-3-(1 H-imidazol-4-yl)propanoic acid are presented. The bifunctional NSO chelating agent could be applied for the development of target-specific technetium and rhenium radiopharmaceuticals.The synthesis and structural characterization of the neutral rhenium complex fac-[Re(NSO)(CO)3],Re-1, where (NSO) is a tridentate bifunctional chelating agent, 3-(carboxymethylthio)-3-(1 H-imidazol-4-yl)propanoic acid (1), is presented. The complex crystallized from methanol–water and its structure was assigned by IR and1H,13C NMR spectroscopies and X-ray crystallography. Furthermore, the analogous technetium complex fac-[99mTc(NSO)(CO)3],99mTc-1, was synthesized in high yield by reacting ligand1 with the fac-[99mTc(OH2)3(CO)3]+ precursor for 30min at 85°C. The tracer complex was found to be more than 95% stable in the L-histidine challenge experiment. Our data indicate that the bifunctional NSO chelating agent1 can be successfully applied for the development of potential99mTc-radiopharmaceuticals.

Keywords: Rhenium; Technetium; Tricarbonyl complexes; Bifunctional


Solvothermal synthesis and characterizations of monophenyltin complexes in drum conformations by Chun-Lin Ma; Yun Ren; Yue-Rong Wang; Ru-Fen Zhang (pp. 881-885).
A series of drum structures of organotin complexes with various carboxylic acids have been solvothermally synthesized and characterized. The molecular structure analyses reveal that all of the complexes have endo drum structures.A series of drum structures of organotin complexes with various carboxylic acids have been solvothermally synthesized and characterized by elemental analysis, FT-IR, NMR (1H,13C and119Sn) spectra and X-ray crystallography. The molecular structure analyses reveal that all of the complexes have endo drum structures. Furthermore, each of the drum structures has a hole, in which atoms of a given radius could be held.

Keywords: Organotin; Carboxylic acids; Drum structures; Solvothermal synthesis


A new method for the synthesis of organic–polyoxometallate hybrid compounds by Fang-Fang Jian; Xian Wang; Jing Wang; Hai-Lian Xiao; Rui-Rui Zhuang (pp. 886-896).
A simple method is reported for the synthesis of four organic-polyoxometallate hybrid compounds. The first crystal structure of a hetero-transition-metal Keggin polyoxometallate, [H4TiW12O40], with a square-planar TiO4 unit is described in this paper. This methodology will hopefully make it possible to synthesise hetero-transition-metal Keggin compounds.Synthetic method for the preparation of organic–polyoxometallate hybrid compounds:Na2MO4+Lewis-base+XCln+HCl→(Lewis-base)mPOM+NaCl+H2OM=Mo or W. X=P, Si, or Ti. n=4 or 5.The reaction of the Na2MoO4 or Na2WO4 salt with organic amine and PCl5, SiCl4 or TiCl4 in hydrochloric acid medium under hydrothermal conditions yields organic–polyoxometallate hybrid compounds, with the following reaction formula: Na2MO4+Lewis-base+XCl n+HCl→(Lewis-baseH) m(XM12O40)+NaCl+H2O (M=Mo or W; X=P, Si, Ti,; n=3–5). By using this method, four new complexes, [(CH3)2NH]3[H3PW12O40] (1), (C2H5OH)3(H3PMo12O40) (2), [DMDA]2[H4SiW12O40]·H2O (3) (DMDA=1N,3N-dimethyl-1,3-diazolidine) and [(DAN)6][H4TiW12O40]·4H2O (DAN=4,4′-dianiline) (4), were obtained, and their crystal structures are reported. Thermal analysis of1,2 and4 has been carried out. The thermal analysis indicates that the Keggin anion skeleton begins to decompose at about 300°C. The possibility of constructing hydrogen-bond interactions by association between the polyoxometallate and the organic compound is explored. The roles of solvents and organic groups in the formation of specific crystalline architectures are discussed. The crystal structure of [H4TiW12O40], a hetero-transition-metal Keggin polyoxometallate with a square-plane TiO4, has been reported. Four architectures developed by hydrogen-bond associations of different Keggin polyoxometallates and organic bearing N–H or O–H donor functions are described. The selected organic modules (4,4′-dianiline, 1,3-dimethylimidazolidine, dimethylamine and ethanol) possess hydrogen-donor functions to allow them to act as bridges between polyoxometallate groups. Depending on the nature of the donor group, the number of hydrogens available for bonding, the geometric features and the sizes of the organic modules, diverse assembling patterns have been observed ranging from one-dimensional to three-dimensional networks. For all the networks, H3O+ and H+ act as actual linkers between the molecular units.

Keywords: Hybrid organic–inorganic compounds; New synthesis method; Keggin polyoxometallate; Crystal structure; Supramolecular architecture


pH-metric, UV–Vis and51V NMR study of vanadium(V) coordination to α-aminohydroxamic acids in aqueous solutions by C.T. Miranda; S. Carvalho; R.T. Yamaki; E.B. Paniago; R.H.U. Borges; V.M. De Bellis (pp. 897-903).
Vanadium(V) complexes with glycinehydroxamic acid and three α-aminohydroxamic acids were analyzed using potentiometry and spectroscopy. Formation constants were calculated and structures proposed based on51V NMR results. VO2L has a distorted trigonal bipyramidal structure and VO2H2L2+ an octahedral one. Both are formed in neutral medium. Only the hydroxamate coordinates toVO2+ .The full speciation of vanadium(V) complexation systems with glycinehydroxamic acid and three α-aminohydroxamic acids (α-alanine-, α-threonine- and α-lysine-) has been achieved using potentiometric and spectroscopic techniques. Formation constants were calculated in a systematic study at different concentrations and ligand-to-metal molar ratios. In each case, in a neutral medium, two complexes were identified with 1:1 and 1:2 metal-to-ligand ratios, both of which can either be protonated or deprotonated depending on the acidity or basicity of the medium. Structures are proposed based on51V NMR results. The 1:1 complex, VO2L (VO2+=dioxovanadium(V) ion and L=α-aminohydroxamate ligand), has a distorted trigonal bipyramidal structure in neutral medium and it exists asVO2HL+ in acidic and asVO2(OH)L- in basic medium. The 1:2 complex,VO2H2L2+, which is formed in neutral medium, has an octahedral structure and also exists asVO2H3L22+ andVO2HL2, in acidic and basic media, respectively. In all cases, only the hydroxamate group appears to be coordinated to theVO2+ group.

Keywords: Vanadium(V); α-Aminohydroxamic acid; NMR; Potentiometry; 51; V NMR; Speciation


Study of half-sandwich platinum group metal complexes bearing dpt-NH2 ligand by Gajendra Gupta; Kota Thirumala Prasad; Babulal Das; Kollipara Mohan Rao (pp. 904-910).
A new series of half-sandwich platinum group metal complexes bearing triazole ligand is reported herein. Molecular structures of two representative complexes have also been studied by single crystal X-ray diffractometer.A quite general approach for the preparation of η5-and η6-cyclichydrocarbon platinum group metal complexes is reported. The dinuclear arene ruthenium complexes [(η6-arene)Ru(μ-Cl)Cl]2 (arene=C6H6, C10H14 and C6Me6) and η5-pentamethylcyclopentadienyl rhodium and iridium complexes [(η6-C5Me5)M(μ-Cl)Cl]2 (M=Rh, Ir) react with 2equiv. of 4-amino-3,5-di-pyridyltriazole (dpt-NH2) in presence of NH4PF6 to afford the corresponding mononuclear complexes of the type [(η6-arene)Ru(dpt-NH2)Cl]PF6 {arene=C10H14 (1), C6H6 (2) and C6Me6 (3)} and [(η6-C5Me5)M(dpt-NH2)Cl]PF6 {M=Rh (4), Ir (5)}. However, the mononuclear η5-cyclopentadienyl analogues such as [(η5-C5H5)Ru(PPh3)2Cl], [(η5-C5H5)Os(PPh3)2Br], [(η5-C5Me5)Ru(PPh3)2Cl] and [(η5-C9H7)Ru(PPh3)2Cl] complexes react in presence of 1equiv. of dpt-NH2 and 1equiv. of NH4PF6 in methanol yielded mononuclear complexes [(η5-C5H5)Ru(PPh3)(dpt-NH2)]PF6 (6), [(η5-C5H5)Os(PPh3)(dpt-NH2)]PF6 (7), [(η5-C5Me5)Ru(PPh3)(dpt-NH2)]PF6 (8) and [(η5-C9H7)Ru(PPh3)(dpt-NH2)]PF6 (9), respectively. These compounds have been totally characterized by IR, NMR and mass spectrometry. The molecular structures of4 and6 have been established by single crystal X-ray diffraction and some of the representative complexes have also been studied by UV–Vis spectroscopy.

Keywords: Arene; Cyclopentadienyl; dpt-NH; 2; Ruthenium


Syntheses, crystal structures and properties of tetrahydrofuran-2,3,4,5-tetracarboxylato bridged copper(II) coordination polymers with alkali metals by Yue-Qing Zheng; Xiao-Yan Han; Hong-Lin Zhu (pp. 911-919).
Four tetrahydrofuran-2,3,4,5-tetracarboxylato bridged copper(II) coordination polymers with alkali metals, Na2[Cu(H2O)(THFTC)]·5H2O1, K2[Cu3(H2O)2(THFTC)2]·9H2O2, Rb2[Cu3(H2O)2(THFTC)2]·6H2O3 and Cs2[Cu3(H2O)2(THFTC)2]·6H2O4 (H4THFTC=tetrahydrofuran-2,3,4,5-tetracarboxylic acid) were prepared and feature 2D layers generated from Cu(II) ions interconnected by tetrahydrofuran-2,3,4,5-tetracarboxylate anions.Four tetrahydrofuran-2,3,4,5-tetracarboxylato bridged copper(II) coordination polymers with alkali metals, Na2[Cu(H2O)(THFTC)]·5H2O1, K2[Cu3(H2O)2(THFTC)2]·9H2O2, Rb2[Cu3(H2O)2(THFTC)2]·6H2O3 and Cs2[Cu3(H2O)2(THFTC)2]·6H2O4 (H4THFTC=tetrahydrofuran-2,3,4,5-tetracarboxylic acid) were prepared from reactions of Cu(NO3)2·3H2O, tetrahydrofuran-2,3,4,5-tetracarboxylic acid and alkali hydroxide or carbonate at pH 5.0–6.0 under ambient conditions. Compound1 features 2D (33·43·54) topological layers generated from six-coordinated Cu2+ cations interlinked by (THFTC)4− anions, and the resulting layers are ecliptically stacked along [100] direction to form lozenge-shaped and octagonal channels filled with Na+ ions and lattice H2O molecules. In2–4, both penta- and hexa-coordinated copper(II) ions are bridged by tetracarboxylate anions to form negatively charged 2D layers formulated as2[Cu(H2O)2L3/2]2− with the corresponding alkali metal cations (K+, Rb+ or Cs+ ions) and hydrogen bonded lattice H2O molecules sandwiched between them. Additionally, the results about i.r. spectroscopic, thermal characterizations and magnetic properties are presented.

Keywords: Copper(II); Alkali metals; Tetrahydrofuran-2,3,4,5-tetracarboxylic acid; Magnetic properties; Coordination polymers


One-dimensional silver(I) 5,5-diethylbarbiturato coordination polymers with N-piperidineethanol and 1,3-bis(4-piperidyl)propane: Syntheses, crystal structures, spectroscopic and thermal properties by Veysel T. Yilmaz; Eda Soyer; Orhan Büyükgüngör (pp. 920-924).
Two new coordination polymers with bridging barbiturate (barb) ligands, [Ag2(barb)(pipet)] n and {Na3[Ag2(barb)2](pippr)·2H2O} n have been synthesized and structurally characterized. They show one-dimensional chain structures which are further extended to supramolecular networks.Two new coordination polymers, [Ag2(barb)(pipet)] n (1) and {Na3[Ag2(barb)2](pippr)·2H2O} n (2) (where H2barb, pipet and Hpippr are 5,5-diethylbarbituric acid, N-piperidineethanol and 1,3-bis(4-piperidyl)propane, respectively) have been synthesized and characterized by elemental analysis, IR, thermal analysis and X-ray single-crystal diffraction techniques. Silver(I) ions in complexes1 and2 are bridged by barb dianions, leading to one-dimensional coordination polymers. In1, the barb ligand acts as a tetradentate bridging ligand, while in2 as a bidendate bridging ligand. The pipet ligand behaves as a bidentate chelating donor, whereas the pippr anion is not involved in coordination and remains as a counter-ion. The one-dimensional chains of1 and2 are further extended into supramolecular networks. Spectral and thermal analysis data for1 and2 are in agreement with the crystal structures.

Keywords: 5,5-Diethylbarbiturate; N; -Piperidineethanol; 1,3-Bis(4-piperidyl)propane; Coordination polymers; Silver(I)


Ultrasonic-assisted synthesis of two new nano-structured 3D lead(II) coordination polymers: Precursors for preparation of PbO nano-structures by Homa Sadeghzadeh; Ali Morsali; Pascal Retailleau (pp. 925-933).
Nano-structures of two new Pb(II) three-dimensional coordination polymers, [Pb2(4-pyc)2I2(H2O)] n (1), {4-Hpyc=4-pyridinecarboxilic acid} and [Pb(3-pyc)I] n (2), {3-Hpyc=3-pyridinecarboxilic acid} were synthesized by a sonochemical method.Nano-structures of two new Pb(II) three-dimensional coordination polymers, [Pb2(4-pyc)2I2(H2O)] n (1), {4-Hpyc=4-pyridinecarboxilic acid} and [Pb(3-pyc)I] n (2), {3-Hpyc=3-pyridinecarboxilic acid} were synthesized by sonochemical method. The new nano-structures were characterized by scanning electron microscopy, X-ray powder diffraction, IR spectroscopy and elemental analyses. Compounds1 and2 were structurally characterized by single crystal X-ray diffraction and are three-dimensional coordination polymers. The thermal stability of compounds1 and2 both their bulk and nano-size were studied by thermal gravimetric and differential thermal analyses and compared. PbO block-structures were obtained by calcination of the nano-structures of compounds1 and2 at 400°C.

Keywords: Nano-structure; Coordination polymer; Lead(II); Crystal structure


Group 12 metal coordination polymers of 1,2-bis(diphenylphosphino)ethane dioxide: A persistent 1D chain motif and consequent 2D and 3D architectures by Xiao-Juan Yang; Xiaoqing Liu; Yanyan Liu; Yongjing Hao; Biao Wu (pp. 934-940).
Group 12 metal coordination polymers with 1,2-bis(diphenylphosphino)ethane dioxide (dppeO2) have been synthesized, which are based on a 1D chain motif constructed by metal ions and bridging dppeO2 ligands. While the terminal halides lead to discrete 1D chains, the SCN and HgI2 units link such chains to 2D and 3D networks.A series of group 12 metal coordination polymers with 1,2-bis(diphenylphosphino)ethane dioxide (dppeO2), {[ZnCl2(μ-dppeO2)]·CH2Cl2} n (1·CH2Cl2), [ZnBr2(μ-dppeO2)] n (2), [CdI2(μ-dppeO2)] n (4), [(HgI2)2(μ-dppeO2)] n (5), [Zn(SCN)(μ-SCN)(μ-dppeO2)] n (6), and [Cd(NO3)(μ-SCN)(μ-dppeO2)] n (7), have been synthesized and structurally characterized. The structures of the compounds are all based on an infinite 1D chain constructed by four-coordinate metal ions and dppeO2 ligands adopting the trans bridging coordination fashion. In the coordination polymers1,2 and4, the halide ions act as terminal ligands, leading to discrete 1D chains with alternative MX2 and dppeO2 repeating units. The mercury compound5 features a unique square-wave-like inorganic chain –[Hg(1)–I–Hg(2)–I]–, and the 1D HgI2(μ-dppeO2) chains are further linked by HgI2 bridges to form a 3D network. In the thiocyanate-containing compounds6 and7, the 1D chains are linked by one (6) or two (7) bridging SCN ions to result in 2D layered structures. Solid-state emission spectra of the coordination polymers show different variations compared to the free dppeO2 ligand, such as enhancement (1,2,6 and7), shift (3 and4) and quenching (5) upon metal coordination.

Keywords: Coordination polymers; Group 12 metals; Bis(diphenylphosphino)ethane dioxide (dppeO; 2; ); Fluorescence


Temperature dependence on recrystallisation of the magnesium phthalocyanine (MgPc) in triethylamine by Jan Janczak (pp. 941-949).
Three complexes of magnesium phthalocyaninato(2−) derivatives in the crystalline form, MgPc(H2O)·(C2H5)3N – (I), MgPc(H2O)2·2(C2H5)3N – (II) and MgPc(H2O)2 – (III), were obtained and structurally characterised. In complexI, the Mg center exhibits square-pyramidal (4+1) coordination environment, whereas inII andIII the Mg center of MgPc exhibit the biaxial (4+2) coordination. Only the complexI exhibits an intense near-IR absorption band in the solid-state.Three complexes of magnesium phthalocyaninato(2−) derivatives in the crystalline form, MgPc(H2O)·(C2H5)3N – (I), MgPc(H2O)2·2(C2H5)3N – (II) and MgPc(H2O)2 – (III), depending on the thermal recrystallisation conditions were obtained and structurally characterised. In complexI, the Mg center exhibits square-pyramidal (4+1) coordination environment, whereas inII andIII the Mg center of MgPc the biaxial (4+2) coordination. Owing to the interaction of the positively charged Mg center with oppositely charged oxygen atom of water molecule in an axial position inI, the Mg atom is significantly displaced (0.451(2)Å) from the plane defined by four isoindole N atoms and leads to distortion of the planar Pc(2−) macrocycle to the saucer-shape form. InII andIII due to the biaxial (4+2) coordination of the Mg center of MgPc, the Mg atom lies on a N4-isoindole plane. The triethylamine solvent molecules inI andII interact with mono or bis(aqua)magnesium phthalocyanine via O–H⋯N hydrogen bonds. The axial Mg–O bond inI is significantly shorter than that in theII andIII complexes. The strength of the Mg–O bond in these complexes is correlated with their thermal stability. From among the complexes only complexI exhibits an intense near-IR absorption band in the solid-state. The spectra ofI,II andIII in solution are very similar.

Keywords: Magnesium phthalocyaninate complexes; Aqua(magnesium) phthalocyanine; Bis(aqua)magnesium phthalocyanine; Crystal structure; Thermal stability; UV–Vis spectroscopy

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