Inorganic Chemistry Communications (v.6, #2)

Contents List (iii-iv).

The preparation and structural characterization of the very strong reducing agent W2(hpp)4, hpp = the anion of 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine, 1, has been accomplished. It has a short distance of 2.1617(4) Å for the quadruply-bonded W2 4+ unit. Compound 1 is very reactive and gives the triple bonded W 2(hpp)4 Cl 2·4CH 2 Cl 2, 2 ·4CH 2 Cl 2 , upon crystallization after mere contact with the haloalkane CH2Cl2. The change in electronic configuration from the σ2π4δ2 in 1 to the σ2π4 system in 2 increases the W–W distance by ca. 0.09 to 2.2497(8) Å. W2(hpp)4 also reduces C60 and 7,7, 8,8-tetracyanoquinodimethide, TCNQ. The latter is reduced to the TCNQ2− anion while the W2 4+ unit is oxidized to the W2 6+ state.
Keywords: Ditungsten; Metal–metal bonds; Guanidinate ligands; Strong reducing agent;

Two homotopic homostranded dinuclear helicates displaying tripodal coordination at each metal atom were synthesised by reaction of bis-3,6-(di-2-pyridylmethyl)pyridazine with M(BF4)2 salts (where M=Ni, Cu), and characterised by single crystal X-ray crystallography. The structures represent closely related examples of this class of helicate, possess a very compact overall size and differ primarily in the coordination geometry of the metal atom. In the nickel helicate the ligand strands adopt a highly contorted bridging geometry which is relieved in the corresponding square pyramidal copper helicate by releasing one of the metal–nitrogen interactions.
Keywords: Helicates; Metallosupramolecular chemistry; Crystal structures; Self-assembly;

Results on the previously described irreversible redox reaction taking place between iron(II) and desferrioxamine B (DFB) under anaerobic conditions have been complemented by additional capillary electrophoresis (CE) and kinetic studies in the present work. Reduction of the oxidizing agent, DFB to monoamide derivative, was confirmed by CE technique and suggestion for the most probable kinetically active species and mechanism of the initial step is discussed in the paper.
Keywords: Fe(II); Desferrioxamine B; Oxidation; Kinetic studies; Capillary electrophoresis;

Self-assembly of two mixed-ligands metal-organic coordination polymers, [MII 2(DPA)2(C4O4)(C2O4)] (M = Cu, Zn) by Cheng-Han Yang; Chih-Ming Chuo; Gene-Hsiang Lee; Chih-Chieh Wang (135-140).
Two coordination polymers with the formula of [M2(DPA)2(C4O4)(C2O4)] (M=Cu 1, Zn 2; DPA=dipyridylamine) were synthesized under hydrothermal conditions. Both complexes are crystallized in triclinic system, space group P 1 ̄ with the cell parameters: a=8.3078(3)  A ̊ , b=9.1192(3)  A ̊ , c=9.2316(3)  A ̊ , α=115.164(1)°, β=94.283(1)°, γ=103.559(1)°, V=603.17(4)  A ̊ 3, Z=2 for complex 1 and a=8.5348(2)  A ̊ , b=9.0451(2)  A ̊ , c=9.0862(3)  A ̊ , α=114.305(1)°, β=100.493(1)°, γ=97.318(1)°, V=612.34(2)  A ̊ 3, Z=2 for complex 2, respectively. X-ray single-crystal structural determinations reveal that these two complexes are both composed of one-dimensional zigzag chains built up via the [M(DPA)]2+ fragments and alternately bridged bidentate μ1,3-C4O4 2−, tetradentate C2O4 2− ligands. The coordination environments of the M(II) centers adopt a slightly distorted trigonal bipyramid bonded with two N atoms of DPA, one O atom of squatate and two O atoms of oxalates. The intrachains N–H⋯O and C–H⋯O hydrogen bonds play an important role on the additional stabilization in constructing the open frameworks.
Keywords: Coordination polymer; Hydrothermal synthesis; Squarate; Oxalate;

A novel complex {[Cd(azpy)3(H2O)2]·2PF6·(azpy)} n (azpy = 4,4-azobispyridine) was synthesized and characterized. The molecule structure shows that it is composed of an infinite “rod” with open sidearms. Two-dimensional plane network with large rhombic channels ca. 13.7×14.7  A ̊ is constructed by the infinite “rods” with sidearms [Cd(4,4-azobispyridine)3(H2O)2] n 2n+ cations simultaneously through themselves the complementary binary hydrogen-bonding and π–π stacking interactions.
Keywords: Crystal structure; Two-dimensional network; Hydrogen-bonding; π–π Stacking;

Synthesis and characterization of potential NO donors: novel iron–sulfur nitrosyls containing the μ-N–C–S skeleton by Olga A. Rakova; Natalyia A. Sanina; Sergey M. Aldoshin; Natalya V. Goncharova; Gennadyi V. Shilov; Yurii M. Shulga; Nikolai S. Ovanesyan (145-148).
Binuclear paramagnetic nitrosyl iron complexes of “g∼2.03 family” were first synthesized. Their structure and properties differ from those of “the red Roussin salt ethers”. The novel nitrosyl iron complexes: [Fe22-SR)2(NO)4nH2O (η1-S, η1-N), n=1–2, R – 3-amino-1,2,4-triazolyl (1), 1,2,4-triazolyl (2), 1-methyl-tetrazolyl (3), benzothiazolyl (4) were obtained by the exchange reaction of Na2Fe2(S2O3)2(NO)4 with heterocyclic thiols and studied by methods of EPR, IR and Mössbauer spectroscopy. The molecular structure of complex 1 was determined by X-ray analysis.
Keywords: Binuclear iron–sulfur nitrosyls; Nitric oxide donors; Heterocyclic thiols;

Density functional theory calculations at the B3LYP level of theory combined with several basis sets were carried out on the structure of bis(1,1-diethyl-3-benzoyl-thioureato) copper(II). The results obtained clearly show two minima with local cis-CuS2O2 geometry, one resembling the X-ray experimental structure, in which the coordination polyhedron is a distorted tetrahedron, and the other with the CuS2O2 moiety nearly planar, resembling the corresponding ureato and a similar mercapto-β-diketone. A third minimum was found for a trans-CuS2O2 conformation. The calculated energy gap between the three structures is lower than 5 kJ/mol.

Synthesis and crystal structure of [Ni{bis(2,5-dihydroxysalicylidene)ethylenediaminato}]: a hydrogen bonded assembly of Ni(II)–salen complex by Mitsuru Kondo; Keiko Nabari; Tomonori Horiba; Yasuhiko Irie; Md.Khayrul Kabir; Ram Prosad Sarker; Emi Shimizu; Yusuke Shimizu; Yumiko Fuwa (154-156).
The hydrogen bonded assembly of salen type complexes was studied. The nickel(II) complex with N,N -bis(2,5-dihydroxysalicylidene)ethylenediaminato was synthesized, and structurally characterized. The compound has two hydroxy groups at the both terminals of the tetradentate ligand. One of the two hydroxy groups of the nickel(II) complex forms a hydrogen bond with a coordinating oxygen donor of the adjacent molecule to yield a hydrogen bonded one-dimensional chain. These chains are also associated by π–π interactions with interlocking fashion to produce a two-dimensional structure. The guest ethanol molecules are incorporated between the two-dimensional layers.
Keywords: Crystal structure; Salen complex; Hydrogen bonded assembly; Coordination network;

Synthesis, structure, and characterization of dicopper(II) complex with a new amidate ligand by Masayuki Koikawa; Hiromi Yamashita; Tadashi Tokii (157-161).
The dicopper(II) complex, (NBu4)2[Cu2(L3-H)2] (1), with a new terdentate ONO-ligand (H3L3-H) containing amide nitrogen has been prepared. X-ray crystallographic analysis reveals that the complex has a di-μ-alkoxo-bridged dicopper(II) structure. Magnetic measurements for 1 indicate that a strong antiferromagnetic interaction is operative in the dicopper core with −2J value of 750 cm−1. Cyclic voltammograms of 1 showed irreversible oxidation waves at +0.62 and +0.88 V which was assigned as metal centered oxidations.
Keywords: Binuclear complex; Dicopper(II) complex; Amidate ligand; Crystal structure;

Crystal structures of palladium(II) and copper(II) complexes of meso-phenyl tripyrrinone by Hiroyuki Furuta; Hiromitsu Maeda; Atsuhiro Osuka (162-164).
Meso-phenyl tripyrrinone (2), which is derived directly from N-confused porphyrin by Cu(II)-assisted oxygenolysis, can serve as a metal coordination ligand using three nitrogens and one oxygen in the core. The crystal structures of Pd(II) and Cu(II) complexes show the similar square-planar N3O-coordination but the mode of oligomeric chains formed in the crystals by π–π stacking interaction is different: zig–zag for Cu(II) and straight for Pd(II) complex.
Keywords: N-confused porphyrin; Tripyrrin; Tripyrrinone; N3O-coordination;

Reaction of 1,3-bis(2-pyridylethynyl)-2-methylbenzene with silver(I) nitrate affords an one-dimensional helical coordination polymer in high yield. The structure of the polymer was confirmed by X-ray crystallography.
Keywords: Coordination polymer; Silver(I) complex; One-dimensional helix; Bis monodentate ligand;

Transition metal complexes [M(Hbta)(H2O)4] [M=Co(II) (1), Ni(II) (2), H3bta=1,3,5-benzenetriacetic acid] have been prepared by reaction of H3bta with the M(OH)2 in water by hydrothermal method. The complexes were characterized by X-ray crystallography and electrospray mass spectrometry. The coordination geometries around Co(II) and Ni(II) atoms are both distorted octahedral with O6 donor set. And the conformation of flexible triacid is cis, trans, trans in the title complexes.
Keywords: Cobalt complex; Nickel complex; Hydrothermal synthesis; Crystal structure;

Reaction of [Os3Rh(μ-H)3(CO)12] 1 with an excess amount of 2-vinylpyridine in refluxing CHCl3 afforded a new cluster, [Os4Rh(μ-H)4(CO)132-NC5H4C2H2)] 2, in moderate yield. A pair of isomers 2a and 2b, which differ in configuration of the metallated vinylpyridine exist in the solution of 2. Through the variable temperature EXSY experiment, the activation barrier (ΔG) for the isomerisation of 2 was determined to be 89.8 kJ mol −1 .
Keywords: Osmium–Rhodium; 2-Vinylpyridine; 2D EXSY-experiment; X-ray crystallography;

Novel polyol route to nanoscale tin sulfides flaky crystallines by Guozhen Shen; Di Chen; Kaibin Tang; Liying Huang; Yitai Qian; Guien Zhou (178-180).
A novel mild solution route, polyol route, was developed to synthesize nanoscale tin sulfides (SnS and SnS2) flaky crystallines. XRD procedure reveals that the products are well crystallized. TEM observation shows that the products are of uniform flaky structure with irregular drapes. And the possible formation mechanism is also discussed.
Keywords: Polyol route; Tin sulfides; X-ray diffraction; Nanoscale crystallines;

Solution-phase synthesis of monodispersed SnTe nanocrystallites at room temperature by Changhua An; Kaibin Tang; Bin Hai; Guozhen Shen; Chunrui Wang; Yitai Qian (181-184).
Monodispersed semiconducting SnTe nanocrystallites was successfully prepared via a solution synthesis route at room temperature. It was found that solvent (ethylenediamine), reductant (KBH4), and tin source (liquid SnCl4) were crucial factors in the preparation of the titled nanocrystals. X-ray powder diffraction (XRD), transmission electronic microscopy (TEM), X-ray photoelectron spectroscopy (XPS) were used to characterize the product. Raman spectrum of the as-prepared sample had a red shift by five or six wavenumbers in comparison with that of the SnTe single crystals.
Keywords: Nanocrystallites; Telluride; Semiconducting; Solution synthesis;

Photoluminescence characteristics of Pb2+ ion in sol–gel derived ZnTiO3 nanocrystals by Shu Fen Wang; Meng Kai Lü; Feng Gu; Chun Feng Song; Dong Xu; Duo Rong Yuan; Guang Jun Zhou; Yong Xin Qi (185-188).
Pb2+ ions doped ZnTiO3 nanocrystal has been prepared by a sol–gel process. The X-ray diffraction patterns indicate that the doped sample exhibits a cubic ZnTiO3 structure. From the luminescence spectra analysis, the introduction of Pb2+ ions into ZnTiO3 results in novel luminescent properties. A red emission band fixed at 620 nm has been observed. The relative intensities of the bands vary with the concentration of Pb2+ ions. The luminescence due to Pb2+-involved centers can be ascribed to the Pb2+-related charge-transfer transition in ZnTiO3 nanocrystals.
Keywords: Pb2+:ZnTiO3; Nanocrystal; Sol–gel; Photoluminescence;

Redox stability of Re(V)–amine complexes by Marı́a Fernanda Cerdá; Eduardo Méndez; Jorge S Gancheff; Carlos Kremer; Ana Marı́a Castro Luna (189-192).
The complete electrochemical characterization of three amine-related complexes containing the [ReO2]+ core was achieved by the use of three different electrode materials. The [ReVO2]+ core, the amine group and iodide were characterized based on the voltammetric behavior on glassy carbon, nickel and gold, respectively.
Keywords: Rhenium; Dioxo complexes; Electrochemistry; Gold; Glassy carbon; Nickel;

Preparation and structures of trinuclear manganese(II) complexes with N-2-pyridiylmethylidene-2-hydroxy-5-substituted-phenylamine by Hideyuki Asada; Katsuya Hayashi; Sei Negoro; Manabu Fujiwara; Takayuki Matsushita (193-196).
The trinuclear manganese(II) complexes, [MnII 3(OAc)4(pap)2(H2O)2] and [MnII 3(OAc)4(5-Cl-pap)2(MeOH)2] were prepared by the reaction of tridentate Schiff base ligands X-papH (X=H, Cl), [N-2-pyridiylmethylidene-2-hydroxy-5-substituted-phenylamine], and MnII(OAc)2·2H2O. In the molecular structures of these complexes, two terminal manganese ions are coordinated with one oxygen and two nitrogen atoms of X-pap, two oxygen atoms of OAc and a solvent molecule, to form a distorted octahedral structure where the central manganese ion resides on a center of symmetry and is surrounded by an O6 donor set of four oxygen atoms from four bridging OAc and two phenolic oxygen atoms of two X-pap ligands.
Keywords: Manganese(II) complexes; Trinuclear complexes; Tridentate Schiff base ligand; Molecular structures;

Relationships among structure and spectroscopic properties in tetrahedrally distorted copper(II) (−)-sparteine dichloride by Yong-Min Lee; Mi-A Kwon; Sung Kwon Kang; Jong Hwa Jeong; Sung-Nak Choi (197-201).
The 1:1 mixed crystalline Cu(C15H26N2)Cl2·Zn(C15H26N2)Cl2, 2, and the host lattice material, Zn(C15H26N2)Cl2, 3, were newly prepared and characterized, and the X-ray crystallographic structures of 2 and 3 determined. Further distortion around the Cu(II) center of Cu(C15H26N2)Cl2, 1, was achieved by introducing 1 into the corresponding diamagnetic Zn(II) host lattice. In the 1:1 mixed crystalline, the dihedral angle between the CuN2 and the CuCl2 planes in the Cu(C15H26N2)Cl2 units increased by ∼11° more than that in the neat 1. The ESR and the optical spectral data in solution and solid states were collected for 1 and 2, and the results correlated with the degree of the distortion around the Cu(II) center. The A values of the ESR spectra and the ligand-field transitions are quite sensitive toward the small change in the dihedral angle between the CuCl2 and the CuN2 planes of the Cu(C15H26N2)Cl2 unit.
Keywords: (−)-Sparteine; Copper(II); Zinc(II); Distortion; Host lattice;

Facile C–N cleavage reactions of secondary and tertiary alkyl amines by P,O chelating rhodium and iridium complexes by Yasuhiro Yamamoto; Jouji Seta; Hiroshi Murooka; Xiao-Hong Han (202-205).
The reactions of Cp*MCl(MDMPP-P,O) (1: M=Rh; 3: M=Ir; MDMPP-P,O=PPh2(C6H3-2-O-6-MeO)) with secondary or tertiary alkyl amine (R2NH or R3N) in the presence of KPF6 underwent a C–N cleavage of amine to afford primary amine complex [Cp*M(MDMPP-P,O) (RNH2)](PF6) (2: M=Rh; 4: M=Ir).
Keywords: C–N cleavage; Rhodium; Iridium; P,O chelating ligand;

Two compounds (NH4)2[M(dod)(H2O)4]2V10O28·6H2O (M = Zn, Mn) have been prepared in aqueous medium. X-ray single-structure analyses reveal that they are isostructural and crystallize in the triclinic space group P 1 . The structures of the two compounds consist of decavanadate anionic clusters and dimeric [M(dod)(H2O)4]2 4+ units, in which the two oxygen atoms from dod ligands ligating M2+ are in a cis fashion. There are a variety of hydrogen bonds including O–H⋯O and N–H⋯O among lattice water molecules, ammonium cations, oxygen atoms of decavanadate and oxygen atoms of dod, which extend the structures into three-dimensional supramolecular arrays.

Dialkylzirconocenes react with molybdenum or tungsten hexacarbonyl and iodine or NBS to form cyclopentadiene molybdenum or tungsten tricarbonyl iodine or bromide.
Keywords: Dialkylzirconocenes; Molybdenum hexacarbonyl; Tungsten hexacarbonyl; Cyclopentadiene transfer;

The doubly-bridging pyridine-2-thionate (pyS) molybdenum complexes [Mo(η3-C3H4R)(CO)2]212:μ-pyS)2 (R=H, 1a; CH3, 1b) are accessible by the reaction of [Mo(η3-C3H4R)(CO)2(CH3CN)2Br] with pySK in CH2Cl2 at room temperature. Complexes 1a and 1b are dimers with each pyS unit chelating through sulfur and nitrogen to one metal center and bridging both metals through sulfur. Treatment of 1a with piperidine affords complex [Mo(η3-C3H5)(η2-pyS)(C5H10NH)(CO)2] (2). Complex 1a is characterized by X-ray diffraction analysis.
Keywords: Doubly-bridging; Pyridine-2-thionate; Molybdenum; X-ray diffraction;

Hydrothermal synthesis, structure, spectroscopic and magnetic properties of a hexanuclear cluster: [{Mn(2,2-bipy)2}2V4O12] by Wen Gu; He-Dong Bian; Jing-Yuan Xu; Shi-Ping Yan; Dai-Zheng Liao; Zong-Hui Jiang (217-220).
The hydrothermal reaction of Mn(OAC)2·4H2O, 2,2-bipyridine (2,2-bipy), NH4VO3, and H3BO3 in water at 180 °C for 48 h yields the bimetallic oxide [{Mn(2,2-bipy)2V4O12] (1) with a {V4O12} ring linked through oxo groups of adjacent vanadium sites to two {Mn(2,2-bipy)2} moieties. It crystallizes in the Orthorhombic system, space group Ibca, a=15.985(4)  A ̊ , b=16.860(4)  A ̊ , c=33.561(9)  A ̊ , Z=8, V=9045(4)  A ̊ 3 , R1=0.0447, wR2=0.0696. Variable temperature magnetic susceptibility measurements (4–300 K) show the occurrence of a weak antiferromagnetic interaction between the manganeses (II) (J=−0.295 cm−1). No splitting corresponding to the Mn hyperfine could have been observed in the ESR spectra.
Keywords: Hydrothermal synthesis; Tetravanadate cluster; Magnetic properties; Manganese (II) complex;

The crystal structure of a new double hydroxyethyl-bridged dizinc(II) complex with macrocyclic ligand by Shu-An Li; Dong-Feng Li; De-Xi Yang; Jin Huang; Yan Xu; Wen-Xia Tang (221-224).
A new dizinc(II) complex with 6,20-bis(2-hydroxyethyl)-3,6,9,17,20,23-hexaaza-tricyclo [23,3,1,111,15]-triaconta-1(29),11(30),12,14,25,27-hexaene (L) was synthesized and characterized. The crystal structure of [Zn2H−2L](ClO4)2 has indicated that both Zn2+ ions are in penta-coordination environment with distorted trigonal bipyramid consisting of three N atoms from diethylenetriamine moieties, one internal O atom of the hydroxyethyl pendant, one intermolar O atom from another hydroxyethyl pendant, and the separation of Zn⋯Zn is 3.05 Å. The two aromatic rings are parallel to each other, with the centroid–centroid distance 9.21 Å. ES–MS spectra showed the main species of [Zn2H−2L]2+, [Zn2H−2L(H2O)2]2+, and [Zn2H−2L(ClO4)]+. The hydrolysis of 4-nitrophenyl acetate catalyzed by [Zn2H−2L]2+ in 10% (v/v) CH3CN at 25 °C, with I=0.10 (NaNO3) and pH 9.0, has shown a second-order rate constant of 0.021  M −1 s −1 .
Keywords: Hydroxyethyl-bridged structure; Dizinc complex; ES–MS; Catalytic hydrolysis;