Inorganic Chemistry Communications (v.6, #3)

Contents List (iii-iv).

A one-dimensional chain compound [Cu(im2-py)(SCN)2] n exhibiting strong ferromagnetic coupling by Licun Li; Daizheng Liao; Songyan Liu; Zonghui Jiang; Shiping Yan (225-228).
A new one-dimensional chain compound [Cu(im2-py)(SCN)2] n (im2-py=2-(2-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl) has been synthesized and characterized by X-ray crystallography and magnetic measurement. The structure consists neutral chains of Cu(im2-py) units linked by thiocyanate bridges. The strong ferromagnetic coupling between copper(II) ion and im2-py radical ligand was observed.

Preparation and characterization of Mg(OH)2 nanorods by liquid–solid arc discharge technique by Lingyun Hao; Chunling Zhu; Xiao Mo; Wanquan Jiang; Yuan Hu; Yurui Zhu; Zuyao Chen (229-232).
The Mg(OH)2 nanorods with diameters of ca. 8–10 nm and lengths of more than 250 nm have been prepared by a novel liquid–solid arc discharge technique. X-ray diffraction (XRD) showed that the Mg(OH)2 nanorods were well-crystallized with the hexagonal structure. The structure features were also analyzed by TEM, HRTEM, and FTIR. Based on the investigation of the influence of current density, discharge time and pH of the electrolyte, the possible growth mechanism of the Mg(OH)2 was discussed.
Keywords: Mg(OH)2; Nanorods; Liquid–solid arc discharge technique;

A novel compound, [Cu(en)2(H2O)]4[Cu(en)2]3.5[PMoVI 8VIV 6O42Cu(en)(1,10-phen)]3·14H2O 1 (en = ethylenediamine, phen = phenanthroline), was synthesized hydrothermally (170 °C, 10 days, autogeneous pressure) and characterized by IR, ESR, elemental analyses and X-ray crystallography. The results of structure determination show that compound 1 contains three different structure cluster anions [PMoVI 8VIV 6O42]7− supporting complex cation [Cu(en)(1,10-phen)]2+, in which one cluster anion possesses typical bicapped Keggin structure, while other two polyanions only have bicapped quasi-Keggin structures, and [Cu(en)(1,10-phen)]2+ is linked through oxygen atoms to different V positions of two bicapped quasi-Keggin units.
Keywords: Bicapped Keggin structure; Polyoxometalates; Hydrothermal synthesis; Crystal structures;

A series of organophosphoryl tungstosilicates α-[RP(O)]2SiW11O39 4− have been synthesized and characterized by elemental analysis, IR, 31 P and 183 W NMR. According to the elemental analysis and spectroscopic data, the hybrid anions consist of an α-[SiWn11O39] framework on which are grafted two equivalent organophosphoryl groups through P–O–W bridges.
Keywords: Polyoxometalate; Organophosphorus; NMR (31P, 183W); Synthesis;

A neutral 2D nanosized molecular square grid: the first vanadium(II)coordination polymer of norfloxacin by Zhen-Feng Chen; Hong Liang; Huai-Ming Hu; Yan Li; Ren-Gen Xiong; Xiao-Zeng You (241-243).
The hydrothermal reaction of norfloxacin (H-Norf) with NH4VO3 yields an unprecedented neutral nanosized molecular square grid containing a direct coordinate bond between quinololine drug and V(II), V(Norf)2·2H2O 1, which is characterized by single X-ray determination and IR spectrum as well as TGA.
Keywords: Crystal structure; Norfloxacin; Vanadium(II) complex; Hydrothermal synthesis;

A novel 3-D chiral coordination polymer: hydrothermal synthesis and structural characterization of [Co33-OH)(μ5-btc)(μ6-Hbtc)(H2O)3·6H2O] n by Zheng-Liang Lü; Wei Chen; Ji-Qing Xu; Li-Juan Zhang; Cheng-Ling Pan; Tie-Gang Wang (244-248).
Keywords: Hydrothermal; Open-framework; Benzene-1,2,4-tricarboxylate; Coordination polymer;

Oxidation of Pt(II) to Pt(IV) complex with hydrogen peroxide in glycols by Young-A Lee; Kyung Ho Yoo; Ok-Sang Jung (249-251).
The reaction of cis, cis-[PtII(9-fm)(dmpda)] (9-fm=9-fluorenylidenemalonate, dmpda=2,2-dimethyl-1,3-propanediamine) with hydrogen peroxide in ethyleneglycol produces cis,trans,cis-[PtIV(9-fm)(OCH2CH2OH)(OH)(dmpda)]. Its crystal structure shows that the local geometry around the platinum atom approximates a typical octahedral arrangement with the added OCH2CH2OH/OH ligands in trans coordination sites. The molecules are packed in a two-dimensional assembly via van der Waals interactions, where the hydrophobic fluorenyl groups are arranged on both faces of the assembly plate whereas the hydrophilic groups fill up the inner part of the plate. The compound bearing both “inorganic OH” and “organic OH” is a potential precursor for further various functionalizations.
Keywords: PlatinumIV complex; Oxidation; Ethyleneglycoloxylation; 9-Fluorenylidenemalonate;

The crystal structures of trifluoroacetato-[meso-tetra(p-chlorophenyl)porphyrinato]thallium(III), Tl[(p-Cl)4tpp](O2CCF3) (1), and pentafluoropropionato-[meso-tetra(p-chlorophenyl)porphyrinato]thallium(III) Tl[(p-Cl)4tpp](O2CCF2CF3) (2), were determined. The coordination sphere around the Tl3+ ion is described as five-coordinate regular square-based pyramid (RSBP) in which the apical site is occupied by an unidentate CF3CO2 ligand for 1 whereas the unidentate CF3CF2CO2 ligand occupies the axial site for 2. The plane of the four pyrrole nitrogen atoms [i.e., N(1)–N(4)] strongly bonded to Tl3+ is adopted as a reference plane 4N. The Tl3+ is moderately out of the 4N plane; its displacement of 0.58 Å (or 0.59 Å) for 1 (or 2) is in the same direction as that of the trifluoroacetate oxygen for 1 (or pentafluoropropionate oxygen for 2). The free energy of activation at the coalescence temperature T c for the intermolecular trifluoroacetate exchange for 1 in CD2Cl2 is found to be ΔG 178=36.6 kJ/mol whereas the intermolecular pentafluoropropionate exchange for 2 in CD2Cl2 is determined to be ΔG 213=41.5 kJ/mol through 19F and 13C NMR temperature-dependent measurements.
Keywords: Crystal structures; Intermolecular exchange; Pentafluoropropionato complex; Thallium meso-tetra-(p-chlorophenyl)porphyrin complexes;

A new compound [As8 IIIV14 IVO42(CO3)][Cu(en)2]3·10H2O (1) has been synthesized from V2O5,As2O3,CuCl2·2H2O, en and H2C2O4·2H2O in aqueous solution using the hydrothermal method and characterized by single-crystal X-ray diffraction analysis. X-ray crystallography reveals that 1 is a novel two-dimensional framework material constructed from the mixed As/V polyoxometalates and coordination groups.
Keywords: Hydrothermal synthesis; Two-dimensional structure; As/V/O polyoxometalates; Crystal structure; Coordination groups;

Crystal structure and superoxide dismutase activity of a six-coordinate manganese(III) complex by Jun Lin; Chao Tu; Hao Lin; Pengju Jiang; Jun Ding; Zijian Guo (262-265).
A six-coordinate manganese(III) complex [Mn(bpb)(H2O)Cl], where H2bpb is N,N -(1,2-phenylene)bis(pyridine-2-carboxaminde), was prepared and characterized by X-ray crystallography. It crystallizes in the monoclinic system, space group P 2(1)/c with a=6.735(1) Å, b=22.910(4) Å, c=11.647(2) Å, β=102.20(1)°, Z=4 and V=1756.5(5)  A ̊ 3 . Mn (III) in the complex adopts an octahedral coordination geometry. The cyclic voltammetry of the complex recorded in DMF indicates a reversible one-electron redox reaction. The complex has been shown to catalyze effectively the dismutation of superoxide (O2 ) in the riboflavin–methionine–nitro blue tetrazolium assay with an IC50 value of 2.93 μM.
Keywords: Crystal structure; Manganese(III) complex; Superoxide dismutase mimic; Six-coordinate complex;

A new cyano-bridged Ca(II)–Fe(III) complex containing both molecular square and linear trimetallic species by Amitabha Datta; G.M. Golzar Hossain; Nirmal Kumar Karan; K.M. Abdul Malik; Samiran Mitra (266-269).
A new cyano-bridged Ca(II)–Fe(III) complex, [Ca2(phen)4(H2O)6Fe(CN)6][{Ca(phen)2(H2O)2Fe(CN)6}2]·3(phen)·(phenH)·14H2O·CH3OH (where phen=1,10-phenanthroline) 1 has been synthesized and structurally characterized. It contains a cyano-bridged trimetallic cationic species [Ca2(phen)4(H2O)6Fe(CN)6]+ 1a with a nearly linear Ca–Fe–Ca arrangement, and an anionic species [{Ca(phen)2(H2O)2Fe(CN)6}2]2− 1b which has a cyano-bridged tetrametallic Ca–Fe–Ca–Fe molecular square framework. In both the species, the Ca atoms are eight coordinated with distorted anti-squareprismatic geometry and the Fe atoms have six coordinated octahedral geometry. The charge is balanced by the protonation of one phen molecule in the lattice.
Keywords: Crystal structure; Molecular square; Trimeric species; Cyano bridge;

Pyrazyne-2-carboxamide (pza) and the iminodiacetato-copper(II) chelate recognise each other by the formation of a single Cu–N4(pza) bond instead of a Cu–N,O(pza) chelate ring. This unexpected finding is explained by the additional formation of two intra-molecular inter-ligand C(aromatic)–H⋯O (carboxyl) interactions which participate in the pza-Cu(IDA) molecular recognition process.Aqua(pyrazine-2-carboxamide)(iminodiacetato)copper(II) monohydrate, [Cu(IDA)(pza)(H2O)]·H2O, was synthesised and characterised by thermal, spectral, magnetic and X-ray diffraction methods. Its crystal structure was solved to a final R1=0.058. The Cu(II) atom exhibits a square base pyramidal coordination (type 4+1) with IDA ligand in mer-tridentate configuration [Cu–N(aliphatic) 1.986(7), Cu–O(carboxyl) 1.933(6) and 1.938(5) Å], the Cu–N4(pza) bond [1.984(7) Å] and Cu–O(apical aqua) bond [2.347(8) Å]. The N4-monodentate ligand role of pza is in contrast with that of the N,O-bidentate pza-Cu(II) chelation in [Cu(pza)2(ClO4)2] or [Cu(acac)(pza)(ClO4)]·H2O. In the molecular recognition between Cu(IDA) chelate and pza the Cu–N4(pyridine-like) coordination mode is preferred because it enables the additional contribution of two weak intra-molecular inter-ligand C(aromatic)–H⋯O (IDA) interactions.
Keywords: Copper; Pyrazine-2-carboxamide; Iminodiacetate; Crystal structure; Molecular recognition; Hydrogen bond;

Thermodynamic properties of the group 13–15 pnictidometallanes [HMYH] n (M=Al, Ga, In; Y=N, P, As; n=1–16) have been predicted at the B3LYP/LANL2DZ(d,p) level of theory. Process of the gas phase generation of [HMYH] n clusters is favorable thermodynamically at low temperatures. Al and N-containing clusters are predicted to be exceptionally stable. Spontaneous generation of [RMYH] n oligomers with n=12–14 is expected during chemical vapor deposition processes at low temperature-high pressure conditions.
Keywords: 13–15 coordination compounds; Clusters; Thermodynamics; Quantum chemistry;

Electronic properties of 1,3,5-tris[4-morpholinophenyl]benzene: a new molecular switch by Christophe Desmarets; Raphaël Schneider; Yves Fort; Alain Walcarius (278-280).
A new electron-donor, 1,3,5-tris[4-morpholinophenyl]benzene 1, was synthetised via nickel-catalysed arylamination reactions and characterised by cyclic voltammetry. It was found that electrochemical or chemical oxidation of 1 generates mono- or di(cation radical)s that are stable over 30 min at room temperature.
Keywords: Nickel; C–N coupling; Radical cation; Electrochemical switching;

μ3-SH dicapped triangular copper(I) complex of bis(diphenylphosphino)amine by Lei Han; Lin-Xi Shi; Li-Yi Zhang; Zhong-Ning Chen; Mao-Chun Hong (281-283).
The reaction between [Cu2(Ph2PNHPPh2)2(MeCN)2](BF4)2 and sodium salt of mercaptoacetic acid (HSCH2COONa) at room temperature for 12 h produced a doubly μ3-SH-bridged tricopper complex [Cu3(μ-Ph2PNHPPh2)33-SH)2](BF4)·2MeOH·Et2O which affords a trigonal bipyramidal core of Cu33-SH)2 with copper ⋯ copper separations around 3.0 Å. The complex is photoluminescent and it displays an emissive maximum at 523 nm in the solid state at 293 K.
Keywords: Bis(diphenylphosphino)amine; Copper(I); Sulfhydryl; Trinuclear;

A new complex of composition {[Co( L1 )(N 3)2]·ClO 4}n (1) (L1=3,14-dimethyl-2,6,13,17-tetraazatricyclo[]docosane) has been synthesized and structurally characterized by a combination of analytical, spectroscopic, and crystallographic methods. The cobalt(III) ion in 1 shows an octahedral geometry with four nitrogen atoms from the tetraaza macrocycle and two nitrogen atoms from the azide ligands. The [Co( L1 )(N 3)2]·ClO 4 unit extends its structure to form the 1D polymer 1 through hydrogen bonding interactions among pre-organized N–H groups of the cobalt(III) macrocycle, azide ligands, and perchlorate anions.
Keywords: Crystal structure; Hydrogen-bonded polymer; Cobalt complex; Tetraaza macrocyclic complex;

Mixed 8-oxyquinolinecalix[4]arene/phenanthroline receptors as luminescence sensors for zinc(II) ions by Izilda A Bagatin; Eduardo S de Souza; Amando S Ito; Henrique E Toma (288-293).
The luminescence behavior of bis-(8-oxyquinoline)calix[4]arene is practically centered on the quinoline chromophore, but involves efficient energy transfer from the calix[4]arene moiety. In the presence of Zn2+ ions, coordination of the quinoline groups is observed, leading to characteristic changes in the absorption, fluorescence and NMR spectra. Energy transfer from the calix[4]arene moiety is precluded by the coordination of the Zn2+ ions. In the resulting complex, a significant decrease in the emission quantum yields takes place. However, by incorporating an additional batho-phenanthroline ligand, a great emission enhancement has been detected, revealing the occurrence of synergistic effects in the bis-(8-oxyquinoline)calix[4]arene(batho-phenanthroline)zinc(II) complex.
Keywords: 8-Oxyquinoline; Calix[4]arene; Fluorescence sensors; Luminescence;

Diimine copper(II) complexes as building blocks for microporous catalytic materials by Wendel Andrade Alves; Saulo Afonso de Almeida Filho; Regina Helena de Almeida Santos; Ana Maria Da Costa Ferreira (294-299).
New copper(II) complexes with tridentate diimine ligands, containing imidazolate-bridging groups, have been prepared as precursors of supramolecular-coordination-chemistry-based assemblies, designed to act as oxidation catalysts. These complexes were isolated as mono-, di- and polymeric or cyclic supramolecular species. In solution, solvent- and pH-dependent equilibria between the mono- and dinuclear complexes, or the mono- and the corresponding polymeric species were detected. Those species were characterized by different spectroscopic techniques (UV/Vis, IR, Raman and EPR), and the X-ray crystallographic structure was determined for one of them. The catalytic activity of the dinuclear and polymeric species in the oxidation of phenol substrates by molecular oxygen were verified, by monitoring the corresponding quinone formation. Cyclic hexa- or tetranuclear copper(II) species, exhibiting imidazolate-bridge groups between the copper centres, were observed to be better catalysts then the analogous dinuclear ones, mainly due the interaction of the substrate with the catalyst hydrophobic cavity. A modulation of the cavity size seems strongly affect the reactivity of these systems.
Keywords: Copper complexes; Polynuclear structures; Catechol oxidation;

Efficient rhenium-catalyzed photochemical carbon dioxide reduction under high pressure by Hisao Hori; Yuko Takano; Kazuhide Koike; Yoshiyuki Sasaki (300-303).
The photocatalytic reduction of CO2-to-CO was carried out under high pressure with [fac-Re(bpy)(CO)3Cl] (bpy=2,2-bipyridine) as the catalyst. The use of high-pressure CO2 gas was much more effective than the addition of excess Cl ions for increasing the stability of the catalyst and achieving efficient CO formation. The turnover number for CO formation at 2.45 MPa of CO2 reached a maximum of 41.8, which was 5.1 times the turnover number for the conventional normal-pressure system.
Keywords: High pressure; Carbon dioxide; Rhenium; Photocatalyst;

Synthesis and catalytic activity in ethylene polymerization of cyclopentadienylterbium dibromides with pyrazole or triphenylphosphine ligand by Alessandra de Souza Maia; Ícaro Sampaio Paulino; Ulf Schuchardt; Wanda de Oliveira (304-307).
Organoterbium compounds TbBr2CpHPz and TbBr2CpPPh3 were obtained by reaction of pyrazole or triphenylphosphine ligands with cyclopentadienylterbium dibromide. These compounds were characterized by elemental analysis, complexometric titration with EDTA, thermal analysis, vibrational spectra in the infrared region and 1H NMR. In a preliminary catalytic study, these compounds were active in ethylene polymerization when MAO was used as cocatalyst, producing low crystalline polyethylene.
Keywords: Organolanthanides; Cyclopentadienyl; Pyrazole; Triphenylphosphine;

The phenanthroline (Phen)-based polyaza ligands can efficiently recognize nucleotides and significantly enhance the rate of ATP hydrolysis under the regulation of metal ions, which act as “messenger” between the substrates and the receptors. The water molecule (or –OH) participates in the catalytic hydrolysis of ATP in different steps with different functions.
Keywords: Recognition; Polyamines; Metal ions; ATP hydrolysis; Water molecule;

The hydrothermal reaction of Cu(NO3)2·2.5H2O with 1,4-benzenedicarboxylic acid (BDCH2) and 4,4-bipyridine (bipy) gave a two-dimensional copper(II) coordination polymer with an empirical of formula of [Cu(BDC)(bipy)](BDCH2) (1). Polymer 1 contains free BDCH2 molecules as guests in channels constructed by Cu, BDC2−, and bipy. The BDCH2 guest molecules are involved in intermolecular hydrogen bonds of the type O–H⋯O, which seem to be main forces to hold the guests in the channels. X-ray powder diffraction (XRPD) studies suggest that polymer 1 and its guest-free form have the same framework. Polymer 1 was structurally characterized by X-ray diffraction.
Keywords: Hydrothermal reaction; Copper coordination polymer; Guest molecules; O–H⋯O hydrogen bond;

Novel dioxotetrazamacrocyclic “sandwich” complexes – synthesis and structural characterization by Deyuan Kong; Xiang Ouyang; Arthur E. Martell; Abraham Clearfield (317-321).
Reaction of 1,4,7,10-tetraazacyclododecane-2,9-dione with copper and cobalt perchlorate in water at 1:1 molar ratio afforded two new crystal-engineered 1:2 ‘sandwich’ type complexes. Both of them are isostructural analogues. Copper complex crystallized in monoclinic space group P21/c with a=9.6888(12), b=12.2956(16), c=10.5661(13), β=104.965(2)°, V=1216.0(3) A ̊ 3 , and Z=2. The Cu(II) ions are six-coordinated by four nitrogen atoms and two amide oxygen atoms. Their coordination geometry can be described as Jahn–Teller distorted octahedra, with elongated Cu–O distances. (2.310(2) Å) Cobalt complex crystallized in monoclinic space group P21/c with a=9.7560(12), b=12.237(16), c=10.7130(13), β=105.194(3)°, V=1234.2(4) A ̊ 3 , and Z=2. The Co(II) ions are also six-coordinated by similar atoms as found in copper complex. But the bond lengths of Co–O 2.0881(13) Å are slightly shorter than respective Co–N.
Keywords: Macrocyclic ligand; Amide group; Crystal structure; Copper; Cobalt;

Cobalt complexes with 2-[(3-aminopropyl)amino]ethanethiol by Takanori Kotera; Atsushi Fujita; Masahiro Mikuriya; Hideyuki Tsutsumi; Makoto Handa (322-324).
The cobalt complexes with 2-[(3-aminopropyl)amino]ethanethiol (Hapaet), [{Co(apaet)2}2Co](ClO4)2 (1) and [Co(apaet)2]ClO4·CH3OH (2) were synthesized and the trinuclear and mononuclear features were elucidated by the elemental analysis, IR and UV–Vis spectroscopies, and magnetic susceptibility measurement. The X-ray crystal structure shows that 1 has a linear trinuclear structure consisting of octahedral–tetrahedral–octahedral coordination environments and 2 has an octahedral CoN4S2 chromophore with meridional chelation of apaet.
Keywords: Cobalt complex; Trinuclear complex; Mononuclear complex; Thiolato complex;

Monomeric Au(II) complex with hematoporphyrin IX by Galina Gencheva; Danyela Tsekova; Georgy Gochev; Dimitar Mehandjiev; Panayot R. Bontchev (325-328).
A stable monomeric Au(II) complex has been synthesized in the course of the Au(III)–hematoporphyrin IX (Hp, I) interaction in aqueous alkaline solution. Distorted octahedral structure with (d xy )1 ground state and general formula Au(II)Hp-2H·2H2O are suggested for the complex. Gold is located in the hole of the porphyrin macrocycle and the water molecules are in axial position. The +2 oxidation state of gold was proven by the corresponding EPR signal and the μ eff value of 2.20 BM obtained. The α 2 value of 0.56 indicated a high degree of covalency of the gold–nitrogen bonds.
Keywords: Gold(II) complexes; Hematoporphyrin complexes; EPR simulation;

Structure of a cavity-encapsulated nanodrop of water [Inorg. Chem. Commun. 6 (2003) 52] by Achim Müller; Hartmut Bögge; Ekkehard Diemann (329).