Inorganic Chemistry Communications (v.11, #12)

N-Picolyl-N′-benzoylthiourea, H2picbtu – A by 1478-1480 (new ligand with a remarkable coo).
Hung Huy Nguyen; Ulrich Abram
Keywords: (NBu4)[ReOCl4] reacts with N-picolyl-N′-benzoylthiourea (H2picbtu) in acetone under formation of the deep-green, tetrameric oxorhenium(V) complex (NBu4)2[{Re2O2Cl5(Hpicbtu)}2O]. The compound represents one of the very rare examples of anionic μ-oxorhenium complexes.(NBu4)[ReOCl4] reacts with N-picolyl-N′-benzoylthiourea (H2picbtu) in acetone under formation of the deep-green oxorhenium(V) complex (NBu4)2[{Re2O2Cl5(Hpicbtu)}2O], which was studied by X-ray diffraction. Two dimeric units with each one bridging, singly deprotonated thiourea ligand are connected by an oxo ligand. Inside the subunits, Hpicbtu coordinates as S,O chelate with a six-membered chelate ring to one rhenium atom, while a five-membered chelate ring is established with the second Re atom and the nitrogen atoms of the picolylamine building block. The compound represents one of the very rare examples of anionic μ-oxorhenium(V) complexes.

Contents List (iii-vii).

Alkynes are easily hydrophosphinated in THF by catalytic [(thf)4Ca(PPh2)2] (1) yielding the appropriate alkenes. No hydrophosphination of these alkenes is observed at room temperature. Thus, 1,4-diphenyl-1,4-bis(diphenylphosphanyl)buta-1,3-diene (3) (P green, C black, H grey) is obtained from butadiyne and HPPh2 with a very good yield in the presence of 5 mol % of [(thf)4Ca(PPh2)2] (1).Hydrophosphination reactions of phenyl substituted alkynes are catalyzed effectively by [(thf)4Ca(PPh2)2] (1). The reactions of diphenylethyne and diphenylbutadiyne with diphenylphosphane in THF in the presence of catalytic amounts of 1 (approx. 5 mol%) yield quantitatively the cis-addition products trans-1,2-diphenyl-1-diphenylphosphanylethene (2) and 1,4-diphenyl-1,4-bis(diphenylphosphanyl)buta-1,3-diene (3), respectively. The phenyl groups in 3 are oriented nearly perpendicular to the butadiene backbone and therefore, the π-systems of the phenyl groups and the butadiene unit show no interaction with each other.
Keywords: Calcium; Catalysis; Hydrophosphination; Phosphanides; Addition reactions;

Preparation, crystal structure and properties of two novel metal-organic frameworks assembled from pyridine-3,5-dicarboxylic acid N-oxide by Yan-Yan Xu; Jian-Guo Lin; Jing Yao; Song Gao; Hui-Zhen Zhu; Qing-Jin Meng (1422-1425).
Two novel coordination compounds were constructed from pyridine-3,5-dicarboxylic acid N-oxide (H2PDCO). Compound 1 features a three-dimensional (3D) network with nonequivalent nodes of (63)2(69  · 85  · 10) topology. Compound 2 exhibits one-dimensional (1-D) double-stranded chains, which are further stacked to result in a 3D microporous network via strong hydrogen-bond and π–π interactions.Two novel coordination polymers, [Cu(PDCO) · (H2O)] n (1) and [Cd(PDCO)(bipy) · (H2O) · 5H2O] n (2), (H2PDCO = pyridine-3,5-dicarboxylic acid N-oxide, bipy = 4,4′-bipyridine), have been synthesized under hydrothermal conditions, and their structures were determined by single-crystal X-ray diffraction studies. Polymer 1 features a three-dimensional (3D) network with nonequivalent nodes of (63)2(69  · 85  · 10) topology. Polymer 2 exhibits one-dimensional (1D) double-stranded chains. The magnetic character of 1 as well as the gas adsorption and luminescent properties of 2 have been investigated.
Keywords: Pyridine-3,5-dicarboxylic acid N-oxide; Microporous MOF; Magnetic property; Luminescence; Weak interactions;

An unprecedented bonding mode for potassium within a PCP-pincer palladium hydride–K-Selectride® complex by Brian J. Boro; Eileen N. Duesler; Karen I. Goldberg; Richard A. Kemp (1426-1429).
Reaction of (PCP)i-PrPdCl and K-Selectride® solution does not yield a simple (PCP)i-PrPdH species, but rather an adduct containing K(sec-Bu3BH). This adduct has been characterized by X-ray crystallography, revealing that the tri-coordinate K+ ion is bound only to hydrides. This [H3K]+ bonding mode for K+ ions was previously unknown.The reaction of (PCP)i-PrPdCl and the commonly-used reductant K-Selectride® solution [K(sec-Bu3BH) in THF] does not yield a simple (PCP)i-PrPdH species, but rather an adduct of the Pd–H that contains bound K(sec-Bu3BH). This adduct has been characterized by X-ray crystallography and shown to be a centrosymmetric dimer in the solid state. The most unique feature of the structure is that the tri-coordinate K+ ion bonds only to the terminal palladium hydride and the two bridging boron hydrides. Despite being prepared in THF, no other donor ligands are bound to K+. This [H3K]+ bonding mode for K+ ions has not been previously reported.
Keywords: Tridentate ligands; Pd complexes; Crystal structure; Hydride ligands;

The syntheses of 3d–3d mixed heterometallic coordination polymers with magnetic properties by Gui-Li Wang; Xiao-Li Yang; Jun Zhang; Yi-Zhi Li; Hong-Bin Du; Xiao-Zeng You (1430-1432).
By using two bidentate ligands, 3d–3d mixed heterometallic coordination polymer [M(ox)(bipy)] (1, M = Co0.72Zn0.28; 2, M = Co0.96Cd0.04; ox = oxalate, bipy = 4,4-bipyridine) have been obtained under hydrothermal conditions. Both process a rare two-dimensional rectangular grid framework with undistinguished heterometallic sites. The co-existence of two metal ions makes them exhibit interesting thermal and magnetic properties in comparison with monometallic organic framework of same structural topology.Novel 3d–3d heterometallic metal-organic frameworks, [M(ox)(bipy)] (1, M = Co and Zn; 2, M = Co and Cd; ox = oxalate, bipy = 4,4-bipyridine), have been synthesized by using two bidentate ligands under hydrothermal conditions. The Co(II) and Zn(II) ions in 1, and Co(II) and Cd(II) in 2 are location disordered, with a molar ratio of 0.72:0.28, and 0.96:0.04, respectively. The co-existence of the two metal ions in the structures makes them more thermally stable than previously reported homometallic polymers of Co(II) or Zn(II) ions. Compound 1 exhibits weaker antiferromagnetism than the pure Co(II) complex owing to the incorporation of Zn(II).
Keywords: Heterometallic; Metal-organic framework; Hydrothermal condition; Magnetism;

3-Nitrobenzaldehyde thiosemicarbazone has formed first example of ionic gold(I)–thiosemicarbazone complex [Au2(3-NO2-Hbtsc)4]Cl2  · 2CH3CN (1), which exhibits an intense fluorescence band at 383 nm (λ ex  = 300 nm), and two bands of medium intensity at 413 and 436 nm (red light emission, λ ex  = 350 nm).Direct reaction of gold(I) chloride with 3-nitrobenzaldehyde thiosemicarbazone (3-NO2-Hbtsc) in the presence of triphenylphosphine in acetonitrile has yielded ionic complex, [Au2(3-NO2-Hbtsc)4]Cl2  · 2CH3CN (1). It exhibited an intense fluorescence band (λ em) at 383 nm (λ ex  = 300 nm), and two bands of medium intensity at 413 and 436 nm (λ ex  = 350 nm). Complex 1 represents first example of ionic gold(I) complex with a thiosemicarbazone.
Keywords: Gold(I); 3-Nitrobenzaldehyde thiosemicarbazone; 2D sheet structure; Fluorescence bands;

By varying the ratio of DMF/MeOH solvent, we obtained a 3D microporous-structural polymer {[Pb6(2,6-pda)6] · H2O} n (1) (2,6-pda = 2,6-pyridyldicarboxylate) and a 1D chain polymer [Pb(mpcp)(OAc)] n (2) (mpcp = methyl-6-(pyridin-2-ylcarbamoyl)picolinate) via the reaction of Pb(OAc)2  · 3H2O and 2,6-dicarboxamido-(2-pyridyl)-pyridine (H2dcapp), which decomposes through lead-induced hydrolysis.Through varying the volume ratio of mixed solvent, we obtained two distinct polymers {[Pb6(2,6-pda)6] · H2O} n (1) (2,6-pda = 2,6-pyridyldicarboxylate) and [Pb(mpcp)(OAc)] n (2) (mpcp = methyl-6-(pyridin-2-ylcarbamoyl)picolinate) by reaction of Pb(OAc)2  · 3H2O and 2,6-dicarboxamido-(2-pyridyl)-pyridine (H2dcapp) decomposed through lead-induced hydrolysis. Photoluminescence investigations reveal that both polymers display enhanced emissions in contrast to the free ligand, respectively.
Keywords: Lead; Metal–organic polymer; Crystal structure; Mixed solution; Fluorescence;

Synthesis and spectroscopic studies on novel Cu(II)–Cu(II) binuclear adducts. EPR evidence for ferromagnetic interactions by S. Pramodini Devi; S. Mimoda Devi; N. Shantibala Devi; R.K. Hemakumar Singh; Manoj Mohapatra; R.M. Kadam (1441-1444).
EPR investigations on two solid complexes [Cu(1-amidino-O-2-methoxyethylurea)]2(H2O)2(SO4)2 (1) and [Cu(1-amidino-O-2-ethoxyethylurea)]2(H2O)2(SO4)2 (2) at RT indicated the formation of ferromagnetically coupled binuclear complexes (S  = 1). In the temperature range 300–475 K, the triplet-state EPR signal disappeared completely and irreversibly with the appearance of a new signal attributable to the mononuclear complex (S  = 1/2).EPR investigations on two solid complexes [Cu(1-amidino-O-2-methoxyethylurea)2]2(H2O)2(SO4)2 (1) and [Cu(1-amidino-O-2-ethoxyethylurea)2]2(H2O)2(SO4)2 (2) indicated the formation of ferromagnetically coupled binuclear complexes (S  = 1) having the isotropic exchange interaction constant J values of 59 and 50 cm−1. The angle between the Cu–Cu direction and the parallel direction (ξ) of the complex 1 has been evaluated. The IR studies suggest the presence of tetrahedral sulfate ion in the complexes. When the EPR spectra were recorded in the temperature range 300–475 K, it was observed that the triplet-state EPR signal disappeared completely and irreversibly at ca. 450 K for complex 1 and at ca. 475 K for complex 2 with the appearance of a new signal attributable to the mononuclear complex (S  = 1/2).
Keywords: EPR; Dicyandiamide; 2-Methoxyethanol; 2-Ethoxyethanol; Binuclear;

A weak-link approach to the synthesis of copper(II)-based metallacycles using a flexible hemilabile 4,7-diazadecanediamide ligand by Min-Shiun Chao; Horng-Hwa Lu; Ming-Liao Tsai; Mei-Chan Ho; Tsung-Hsuan Hsieh (1445-1447).
Successful conversion of 1 to a metallacycles 2 by changing the coordination mode of a flexible hemilabile 4,7-diazadecanediamide under mild conditions demonstrates that the weak-link approach can apply to a Cu(II) system for the first time.Employment of a weak-link approach to the synthesis of Cu(II) metallacycle [Cu2(C8H18N4O2)2(C2H8N2)2] · 4Cl (2) from [Cu(C8H18N4O2)(Cl)]Cl · 2H2O (1) under very mild reaction conditions was achieved in high yield using a flexible hemilabile multidentate ligand, 4,7-diazadecanediamide.
Keywords: Weak-link approach; Diaminodiamide; Cu(II); Complex;

The long chain-substitued phthalonitrile (3) was synthesized by nucleophilic displacement of nitro group in 4-nitrophthalonitrile with N,N-bis[2-(2-hyroxyethoxy)ethyl]-4-methylbenzenesulfonamide (1). The novel metal-free phthalocyanine (4) and metallophtalocyanines (58) have been synthesized by cyclotetramerization reaction of phthalonitrile derivative (3). Long chain-substitued Pcs showed the enhanced solubility in organic solvents. The new compounds were characterized by a combination of IR, 1H NMR, 13C NMR, UV–vis, elemental analysis and MS spectral data.The long chain-substitued phthalonitrile (3) was synthesized by nucleophilic displacement of nitro group in 4-nitrophthalonitrile with N,N-bis[2-(2-hyroxyethoxy)ethyl]-4-methylbenzenesulfonamide (1). The novel metal-free phthalocyanine (4) and metallophtalocyanines (58) have been synthesized by cyclotetramerization reaction of phthalonitrile derivative (3). Long chain-substituted Pcs showed the enhanced solubility in organic solvents. The new compounds were characterized by a combination of IR, 1H NMR, 13C NMR, UV–Vis, elemental analysis and MS spectral data.
Keywords: Phthalocyanine; Cyclotetramerization; Metallophthalocyanine; Synthesis;

Reaction of the titanocene alkyne complex Cp2Ti(η2-Me3SiC2SiMe3) with methanol: Preparation and characterization of a novel trinuclear titanium complex [{Cp2Ti(OMe)}2{Ti(OMe)4}] by Perdita Arndt; Vladimir V. Burlakov; Christian Fischer; Detlef Heller; Marcus Klahn; Anke Spannenberg; Uwe Rosenthal (1452-1454).
The titanocene alkyne complex Cp2Ti(η2-Me3SiC2SiMe3) (1) reacts with methanol to yield depending on the reaction conditions (solvent, temperature) different titanium methoxides [Cp2Ti(OMe)]2 (2a) and [{Cp2Ti(OMe)}2{Ti(OMe)4}] (3). The structure of the trinuclear complex 3, consisting of titanium III and IV, was confirmed by X-ray studies.The titanocene alkyne complex Cp2Ti(η2-Me3SiC2SiMe3) (1) reacts with methanol to yield depending on the reaction conditions (solvent, temperature) different titanium methoxides [Cp2Ti(OMe)]2 (2a) and [{Cp2Ti(OMe)}2{Ti(OMe)4}] (3). The structure of the trinuclear complex 3, consisting of titanium III and IV, was confirmed by X-ray studies.
Keywords: Titanocene; Ti(III)/Ti(IV); Methoxide; Crystal structure;

A novel metal–organic coordination polymer, namely, {[K2(H2O)6][Cd3(1,2,4,5-BTC)2]} n (1) (1,2,4,5-BTC = 1,2,4,5-benzenetetracarboxylate), was synthesized in an ionothermal reaction by using an ionic liquid 1-ethyl-3-methylimidazolium bromide ([EMIM]Br) as solvent.A novel metal–organic coordination polymer, namely, {[K2(H2O)6][Cd3(1,2,4,5-BTC)2]} n (1) (1,2,4,5-BTC = 1,2,4,5-benzenetetracarboxylate), was synthesized in an ionothermal reaction by using an ionic liquid 1-ethyl-3-methylimidazolium bromide ([EMIM]Br) as solvent. Complex 1 features a novel 3-D (4, 8)-connected porous anionic architecture constructed by linking trinuclear Cd subunits with 1,2,4,5-BTC4− ligands, which are further filled with 1-D [K2(H2O)6] cationic chains.
Keywords: Ionic liquid; Ionothermal; Coordination polymer; 1,2,4,5-Benzenetetracarboxylate;

Platinum(VI) dihydroxo tetramesitylporphyrin; characterization and chemical reactivity by Nasser Safari; Saeed Rayati; Akbar Ghaemi; Farzad Bahadoran; Hamid Reza Khavasi (1459-1461).
Tetramesitylporphyrin platinum(VI) dihydroxo complex, TMPPt(OH)2  · 2 benzoate was synthesized by addition of two equivalent of meta-chloroperbenzoic acid molecules to the tetramesitylporphyrin platinum(II). This complex was characterized by X-ray diffraction and spectroscopic methods, and is capable to convert two molecules of triphenylphosphine to triphenylphosphine oxide.Tetramesitylporphyrin platinum(VI) dihydroxo complex, TMPPt(OH)2  · 2 benzoate was synthesized by addition of two equivalent of meta-chloroperbenzoic acid molecules to the tetramesitylporphyrin platinum(II). This complex was characterized by X-ray diffraction and spectroscopic methods, and is capable to convert two molecules of triphenylphosphine to triphenylphosphine oxide.
Keywords: Platinum(VI) dihydroxo; Oxidation; Cytochrome P-450; Triphenylphosphine; meta-Chloroperbenzoic acid;

Synthesis, characterization and catalytic properties of an N-heterocyclic carbene palladium-based complex by İsmail Özdemir; Hakan Arslan; Serpil Demir; Don VanDerveer; Bekir Çetinkaya (1462-1465).
A novel palladium(II) complex bearing N-heterocyclic carbenes have been synthesized by the reaction of Ag–NHC complex with the PdCl2(PhCN)2 into dichloromethane and characterized by elemental analyses, infrared, 1H and 13C NMR spectroscopy and single-crystal X-ray diffraction analysis. The catalytic studies on palladium(II) complex indicate that it is a potent catalyst for the Suzuki–Miyaura reaction of aryl chlorides with phenylboronic acid under air atmosphere.A palladium(II) complex, bis[1,3-bis-(2,4,6-trimethylbenzyl)benzimidazol-2-ylidene]palladium(II) chloride, Pd(NHC), bearing N-heterocyclic carbenes has been synthesized and characterized by elemental analysis, IR spectroscopy and 1H and 13C NMR spectroscopy. Crystal structure details of Pd(NHC) are also presented. The palladium centre in the complex lies on a crystallographic inversion centre and occupies a square-planar environment, with both chloride and N-heterocyclic carbene ligands adopting a trans arrangement with Cl–Pd–Cl and C–Pd–C angles are precisely 180°. The palladium–carbene complex was tested as a catalyst in the Suzuki–Miyaura cross-coupling reaction.
Keywords: N-Heterocyclic carbenes; Palladium–carbene complexes; Crystal structure; Suzuki–Miyaura cross-coupling reaction; Palladium catalyst;

Dinuclear copper(II) complex with tetrathiafulvalene-based bis-acetylacetonate ligands by Yu-Jia Li; Wei Liu; Yi-Zhi Li; Jing-Lin Zuo; Xiao-Zeng You (1466-1469).
A dinuclear copper(II) complex with cis-bis(acetylacetonate)tetrathiafulvalene ligand, [Cu2(cis-acac2)2  ⋅ 2DMF ⋅ 2H2O] (1), was prepared and structurally characterized. The redox properties of both the interesting ligand and the metal complex were investigated by cyclic voltammetry.Deprotection of the cyanoethyl groups with 2 equivalents of the strong base (CsOH) and subsequent reaction with the electrophilic 3-chloro-2,4-pentanedione afford the bis(acetylacetone)tetrathiafulvalenes, trans- and cis-acac2. The formation of the dinuclear rectangle-shaped complex [Cu2(cis-acac2)2  ⋅ 2DMF ⋅ 2H2O] (1), demonstrates the chelating ability of the interesting TTF-acetylacetonate ligand. Cyclic voltammetry experiments have evidenced the two one-electron steps to the radical cation and dication species of the new ligand, and the two quasi-reversible two-electron oxidation processes of complex 1.
Keywords: Syntheses; Crystal structures; Tetrathiafulvalene; Cyclic voltammetry; Copper complexes;

A thiocyanato bridged heteronuclear polymer Cd(SCN)3Cu(en)2NO3 (en = ethylenediamine) was presented. 2D networks of the complex is achieved by the two bridge modes of 1, 3-μ-SCN and 1,1,3-μ-SCN between Cd(II) and Cu(II) centers. The 2D layers was further interacted each other feathering 3D network through multiform hydrogen bonds.A novel heteronuclear polymeric complex Cd(SCN)3Cu(en)2NO3 (1) (en = ethylenediamine) has been synthesized and structurally characterized. The Cd(II) atom is surrounded by three S atoms and three N atoms from four 1,3-μ-SCN and two 1,1,3-μ-SCN to attain a distorted octahedral coordination geometry. Six Cd(II) centers are linked by twelve thiocyanato bridges to form hexagonal metallocyclic unit [Cd6(SCN)12] and extend a 2D network. Moreover, a 1,1,3-μ-SCN links two cadmium and one copper metal atoms. The luminescent properties of 1 in the solid state were investigated.
Keywords: Heteronuclear complex; Thiocyanato bridged; Crystal structure; Luminescent properties;

[Ni3(pymp)4(pya)2](NO3)2(CH3OH)2 (1), [Ni3(pymp)4(pya)2]Cl2(CH3OH)2 (2) and [Ni(pymp)2(py)2] (3) (Hpymp = 2-[(pyridine-2-ylimine)methyl]phenol, pya = pyridin-2-amine and py = pyridine) were synthesized and characterized. Crystal structures reveal that 1 and 2 contain phenoxo-bridged and N–C–N bridged linear trinuclear cores (uncommon for trinuclear nickel complexes), with the central Ni(II) being coordinated in a NiO4N2 fashion while the two terminal Ni(II) atoms adopt a NiO2N4 coordination mode. Two novel coordination modes of Hpymp ligand are presented in 1 and 2. Complex 3 displays a NiO2N4 coordination mode with the Ni(II) in a slightly distorted octahedral environment. Magnetic measurements of 1 indicated that the Ni centers are ferromagnetically coupled.[Ni3(pymp)4(pya)2](NO3)2(CH3OH)2 (1), [Ni3(pymp)4(pya)2]Cl2(CH3OH)2 (2) and [Ni(pymp)2(py)2] (3) (Hpymp = 2-[(pyridine-2-ylimine)methyl]phenol, pya = pyridin-2-amine and py = pyridine) were synthesized and characterized. Crystal structures reveal that 1 and 2 contain phenoxo-bridged and N–C–N bridged linear trinuclear cores (uncommon for trinuclear nickel complexes), with the central Ni(II) being coordinated in a NiO4N2 fashion while the two terminal Ni(II) atoms adopt a NiO2N4 coordination mode. Two novel coordination modes of Hpymp ligand are presented in 1 and 2. Complex 3 displays a NiO2N4 coordination mode with the Ni(II) in a slightly distorted octahedral environment. Magnetic measurements of 1 indicated that the Ni centers are ferromagnetically coupled.

Under hydrothermal conditions using a triazole derivative ligand 3-carboxylic acid-4H-1,2,4-triazole (HL) and corresponding lead(II) salts, a novel two-dimensional(2D) lead(II) complex {[Pb(L)(μ2-Cl)(H2O)} n (1) has been isolated. In 1 Pb2Cl2(H2O)2 building blocks can be observed, which are extended by tetra-dentate coordinated L ligands to form a 2D corrugated layered structure. 1 also represents a novel example of luminescent lead(II) frameworks with triazole derivatives. Solid-state fluorescence spectrum of 1 exhibits the excited peak at 376 nm while the emission peak at 604 nm.Under hydrothermal conditions using a triazole derivative ligand 3-carboxylic acid-4H-1,2,4-triazole (HL) and corresponding lead(II) salts, a novel two-dimensional(2D) lead(II) complex {[Pb(L)(μ2-Cl)(H2O)} n (1) has been isolated. In 1 Pb2Cl2(H2O)2 building blocks can be observed, which are extended by tetra-dentate coordinated L ligands to form a 2D corrugated layered structure. 1 also represents a novel example of luminescent lead(II) frameworks with triazole derivatives. Solid-state fluorescence spectrum of 1 exhibits the excited peak at 376 nm while the emission peak at 604 nm.
Keywords: 3-Carboxylic acid-4H-1,2,4-triazole; Pb2Cl2(H2O)2; Tetra-dentate; Fluorescence;