Inorganic Chemistry Communications (v.5, #4)

Contents List (iii-iv).

The crystal structure of the title complex, [CuCl2(C12H14N4)(H2O)], is composed of discrete molecules. The Cu(II) atom is coordinated by two chloride ligands and three nitrogen atoms from the ligand in a distorted tetragonal pyramidal coordination environment with Cu–N distances of 2.053(2), 2.0023(2) and 2.035(2) Å, Cu–Cl distances of 2.538(1) Å and 2.302(1) Å and N–Cu–N of 90.97(0.07), 167.16(0.07) and 80.32(0.07)° and Cl–Cu–Cl angles of 106.90 (0.003)°.
Keywords: Copper complex; Spectroscopic; Crystal Structure;

The complex (dmp)CuI(BH4) with dmp=2,9-dimethyl-1,10-phenanthroline displays a long-wavelength absorption at λ max =465  nm which is assigned to a BH4 →dmp ligand-to-ligand charge transfer (LLCT) transition. In the solid state the LLCT state is emissive (λ max =626  nm). In non-coordinating solvents such as CH2Cl2,CHCl3 or toluene the complex undergoes a photoredox decomposition leading to the generation of metallic copper. At λ irr =436  nm  (dmp)Cu I (BH 4) disappears with φ=1.2×10−3.
Keywords: Electronic spectra; Luminescence; Charge transfer; Copper complexes; Borohydrides; Photochemistry;

Synthesis of silver nanowires by a sonoelectrochemical method by Jun-Jie Zhu; Qiao-Feng Qiu; Hui Wang; Jian-Rong Zhang; Jian-Ming Zhu; Zhi-Qiang Chen (242-244).
A novel method for the preparation of silver nanowires without any template is presented via a sonoelectrochemical route in an aqueous solution containing silver nitrate and ethylenediamine tetraacetic acid (EDTA) under N2 atmosphere. The electrolysis was carried out with controlled-current and controlled-potential, respectively. The products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and selected area electron diffraction (SEAD). Almost uniform silver nanowires were observed in the TEM images. An SEAD revealed the silver nanowires with single crystalline nature.
Keywords: Sonoelectrochemistry; Synthesis; Nanowire; Silver;

The unexpected synthesis of rhodium(I) complexes with the 1-(2-pyridyl)-3-oxo-1-propenoxide anionic ligand by Ana P. Martı́nez; Marı́a P. Garcı́a; Fernando J. Lahoz; Luis A. Oro (245-248).
The enaminone compound 1-(2-pyridyl)-3-dimethylamine-1-propenone (1) reacts with [{Rh(μ-OY)(COD)}2] (OY=OMe, OH) dimers in the presence of water to form a mononuclear square-planar rhodium(I) complex 2, which incorporates the unexpected 1-(2-pyridyl)-3-oxo-1-propenoxide ligand (N, O). The mediation of the metal in this ligand transformation is demonstrated. The crystal structure of [Rh(N,O)(COD)] (2) reveals the coordination of the new propenoxide ligand as a N,O-bidentate with the presence of an additional non-coordinated aldehyde group. Complex 2 reacts with CO by displacement of the COD molecule, but maintaining the N,O-coordination of the chelate propenoxide ligand.
Keywords: Rhodium complex; Chelate N,O ligands; Crystal structure;

The first uranium based liquid crystals. Uranyl metallomesogens from β-diketone and tropolone ligands by Stephen Clark; James M. Elliott; John R. Chipperfield; Peter Styring; Ekkehard Sinn (249-251).
A tropolone ligand (5-hexadecyloxytropolone) complexed with uranyl, produces a very narrow liquid crystal range at high temperatures. A β-diketone ligand (1-[4-decyloxyphenyl]-3-tridecylpropane-1,3-dione) designed for a more extensive liquid crystal range, produces a uranyl liquid crystal at low temperatures, which remains liquid crystalline while supercooling down to room temperature. This opens the way to a host of interesting new superheavy metallomesogens, uranium metallomesogens, low melting metallomesogens, and possible radiopharmaceuticals.

Synthesis of a gold(I) complex with a (thio)phosphine-modified β-cyclodextrin by Manfred T. Reetz; Ioannis D. Kostas; Siegfried R. Waldvogel (252-254).
A gold(I) complex with the bidentate ligand 6A-S-[2-(diphenylphosphino)-ethyl]thio-β-cyclodextrin has been prepared. The complex has been studied by mass spectrometry as well as IR and NMR spectroscopy. The influence of the ligand:metal ratio on the coordination mode has also been examined.
Keywords: β-Cyclodextrin; Bidentate ligand; Gold complex; Antiarthritic drug;

A series of mixed-ligand heterobimetallic complexes of the form MM(C7H4NS2)4(py)2 and MM(C7H4NS2)4(N–N) and complex heterobimetallic salts [M(N–N)3][M(C7H4NS2)4] [M=Co(II) or Ni(II); M=Zn(II) or Hg(II); N–N=ethylenediamine(en) or 1,10-phenanthroline(phen)] has been prepared and characterized by IR and UV–visible spectroscopy, microanalysis and conductivity techniques. Except with NiZn(C7H4NS2)4(py)2 which is insulator all of the compounds exhibit σ rt in the 10−12–10−5   S cm −1 range and semiconduct over 303–393 K.
Keywords: Mixed-ligand heterobimetallic complexes; Electronic spectra; Solid-state conductivity; Semiconductors;

An oxygen-rich chromium (VI) complex, Ph4P[CrO3(OH)], reduces water present in non-aqueous media, viz, acetonitrile or dichloromethane to dihydrogen fuel autocatalytically, while oxidising functionalized organic substrates. The same catalyst also shows a catalase like activity on H2O2 also in non-aqueous media.
Keywords: Oxygen-rich chromium (VI) complex; Water-splitting to dihydrogen; Autocatalysis; Catalase activity;

The title complex was obtained by reacting CoI2 with thiophene-2,5-di(carboxylatomethylenebenzotriazole) in dichloromethane. The single-crystal X-ray structure analysis of the green material reveals a polymeric chain of CoI2 units, tetrahedrally coordinated and connected by the 3-nitrogen atoms of the two benzotriazole groups of the multifunctional ligand. The paramagnetic cobalt(II) polymer can be oxidised by hexachloroethane to give the corresponding cationic cobalt(III) complex [CoI2(C6H4N3CH2CO2C4H2SCO2CH2C6H4N3)(H2O)2]+ which is diamagnetic and precipitates as the green–yellow chloride salt.
Keywords: Cobalt; Polymer; Nitrogen ligand;

Tungsten(VI) complexes of the type trans-[WCl2(diol)(OAr)2] were studied as catalyst precursors for ROMP of norbornene and dicyclopentadiene. These compounds form active catalysts when treated by simple Grignard reagents, such as methyl magnesium iodide or neophyl magnesium chloride. Moreover, polymerisations can be run under ambient atmosphere without complicated inert atmosphere techniques.
Keywords: Alkoxide complexes; Chloro complexes; Phenolate ligands; Tungsten; Catalysis;

The complex hexakis (N-methylimidazole) copper(II) salicylate, [Cu(N-meim)6](sal)2, has been prepared from the reaction of copper(II) aspirinate with N-methylimidazole and was crystallographically and spectroscopically characterized. The complex crystallizes in the space group P21/c with a=13.324(2), b=7.870(1) and c=20.039(3) Å and β=108.41(1)°. It is structure that of a tetragonally distorted octahedral copper(II) cation with six coordinated N-methylimidazole ligands and two salicylate counter ions. The superoxide dismutase (SOD) mimetic activity of the complex has been investigated by utilizing xanthine–xanthine oxidase assay. The results indicate that the complex is potent SOD mimic.
Keywords: Copper(II) salicylate; N-methylimidazole; SOD;

Two new 19-vertex metallaboranes, [B18H20Ni(η5-C5H5)][N(CH3)4] and [B18H19(2-THF)Ni(η5-C5H5)], were isolated from the reaction of anti-B18H22 with nickelocene, [Ni(η5-C5H5)2], in high yields. The complexes were characterized by multinuclear NMR (1H, 13C, 11B), IR and UV–vis spectroscopy. Single-crystal X-ray diffraction analyses of these new complexes confirmed their structures as 19-vertex conjuncto-metallaborane clusters.
Keywords: Metallaboranes; Borane clusters; Crystal structures; Nickel–borane complexes;

The new ligand o-C6H4[CH2OCH2C(3-Phpz)3]2 (pz=pyrazolyl ring) reacts with AgBF4 to yield the coordination polymer {o-C6H4[CH2OCH2C(3-Phpz)3]2Ag2(BF4)2} n . The organometallic supramolecular architecture contains two different types of silver(I) cations arranged in bimetallic units forming a 1D coordination polymer. The bimetallic units show three different types of bridging interactions, including a μ-κ12-tris(3-Ph-pyrazolyl)methane unit, a silver η2-bonded to a phenyl group and π–π stacking interactions.
Keywords: 1D coordination polymer; Silver(I); Tris(pyrazolyl)methane ligand; η2-arenel;

An iron(III)trichloride adduct of N-isopropylsalicylaldimine: preparation, X-ray structure and NMR spectroscopic characterization by Jennifer L. Kisko; Michele A. Torzilli; Kai Liu; Ann E. McDermott; Robert H. Beer (283-287).
The reaction of anhydrous iron(III)trichloride and N-isopropylsalicylaldimine (LiprH) in benzene yields the adduct Fe(LiprH)Cl3. The X-ray crystal structure of the compound shows a mononuclear tetrahedral iron(III) center with only the oxygen atom of the potentially bidentate Schiff base ligand coordinated to iron(III)trichloride. The imine nitrogen of the coordinated ligand is protonated and non-coordinating with LiprH binding to iron in its phenolate-iminium (zwitterion) form with a {FeO-   -   -HNC} intraligand hydrogen bond. The solid-state infrared spectrum of Fe(LiprH)Cl3 exhibits an increase in the energy of the CN stretch from 1631  cm −1 in the free ligand to 1649  cm −1 consistent with the protonation of the imine upon coordination. The solution 1H NMR spectrum of Fe(LiprH)Cl3 and the solution 2H NMR spectrum of its deuterated derivative Fe(LiprD)Cl3 also support this coordination mode displaying isotropically shifted iminium C1 H and N2H resonances at 21.8 and −43.7 ppm, respectively. A well-resolved solid-state 15N magic angle spinning NMR resonance with a centerband at 970 ppm can be observed at 25 °C with the 15N enriched derivative of Fe(LiprH)Cl3.
Keywords: Iron(III); Schiff base ligands; X-ray crystal structure; 1H, 2H, and 15H NMR spectroscopy of paramagnetic complexes; Solid-state NMR spectroscopy; Hydrogen bonding;

A polymerizable pyrrole–cobaltocenium receptor for the electrochemical recognition of anions in solution and immobilised onto electrode surfaces by Isabel del Peso; Beatriz Alonso; Francisco Lobete; Carmen M. Casado; Isabel Cuadrado; José Losada del Barrio (288-291).
Electrochemical and 1H NMR investigations showed that the first example of cobaltocenium moiety covalently attached to a pyrrole group (1) recognises and senses anionic guest species not only in solution but also immobilised onto electrode surfaces by electropolymerisation.
Keywords: Molecular recognition; Anion receptors; Cobaltocenium; Modified electrodes; Pyrrole;

Synthesis, spectroscopic studies and structure prediction of the new Tb(3-NH2PIC)3·3H2O complex by M.E. de Mesquita; S.A. Júnior; F.C. Oliveira; R.O. Freire; N.B.C. Júnior; G.F. de Sá (292-295).
The synthesis, spectroscopic properties and structure prediction of the complex of Tb(III) with 3-aminopyridine-2-carboxylic acid (3-NH2PIC) are described. The complex was characterized by elemental analysis and IR, absorption and emission spectra. The C, H and N elemental analysis consistent with the formulation of the compound as Tb(3-NH2PIC)3·3H2O. This complex exhibits a luminescence intensity that is attenuated to that of its Eu+3 congener. The Sparkle model, used for structural computations of lanthanide complexes (SMLC), was applied to the new complex. The calculation used an INDO/S-CI model for determination of the electronic spectrum.
Keywords: Terbium(III); 3-Aminopyridine-2-carboxylic acid; Luminescence; Sparkle model;

The reaction of the [nido-7-(OCH2)-8-Me-7,8-C2B9H9]3− trianion with anhydrous MeMCl3 (M=Si, Ge) in 1:1 molar ratio in dry toluene, followed by re-crystallization from a solution of toluene/heptane, resulted in the formation of the corresponding novel half-sandwich constrained-geometry group 14 metallacarboranes, closo-1-M(Me)-2-(1-η1(σ)-OCH2)-3-Me-η5-2,3-C2B9H9 [M=Si (3), Ge (4)] in 48% and 56% yields, respectively.
Keywords: Silacarborane; Germacarborane; Half-sandwich; C(cage)-Alkyloxo; Constrained-geometry;