Inorganic Chemistry Communications (v.6, #10)

Contents List (iii-iv).

Low temperature activation of Cp* 2Ti[η 1,η 1- CH2CH(CH2CHCH2)CH2] (3) with [HN(CH3)(C6H5)2] [B(C6F5)4] led to the formation of Cp* 2Ti[η 1,η 2-CH2CH(CH3)CH2CHCH2][B(C6F5)4] (6) as determined by 1H NMR spectroscopy. Cp* 2Ti[η 1,η 2-CH2CH(CH3)CH2CHCH2][B(C6F5)4] undergoes rapid quantitative β-allyl elimination at temperatures as low as −140 °C. The resulting cationic titanium allyl complex [Cp* 2Ti(η 3-CH2CHCH2)][B(C6F5)4] (4) exhibits a static structure at low temperatures, but interconversion of η 3η 1 binding modes can be observed at higher temperatures. Lineshape analysis of this process yielded ΔG (−10 °C)= 13.7 ± 0.6 kcal mol−1, ΔH =9.8 ± 0.6 kcal mol−1, and ΔS =−15 ± 3 eu. The use of neutral borane B(C6F5)3 also resulted in β-allyl elimination with the formation of [Cp* 2Ti(η 3-CH2CHCH2)][CH2=CHCH2B(C6F5)3] (8).
Keywords: Metallocene; Alkyl-alkene Complex; Titanium; β-Allyl elimination;

Cyclohexadiene-linked clusters: synthesis and molecular structure of [{Os4(CO)8(MeCCMe)(η6-C6H6)}2222-C6H8-1,3)] by Andrew J. Edwards; Jack Lewis; Chi-Keung Li; Catherine A. Morewood; Paul R. Raithby; Gregory P. Shields (1291-1293).
The linked clusters [{Os4(CO)8(RCCR)(η6-C6H6)}2222-C6H8-1,3)] and [{Os4(CO)8(RCCR)(η6-C6H6)}2222-C6H8-1,4)] (R=Me, Ph) have been prepared by the reaction of two equivalents of [Os4(CO)9(RCCR)(η6-C6H6)] with an equivalent of 1,3- or 1,4-cyclohexadiene in the presence of MeCN.The reaction of [Os4(CO)9(RCCR)(η6-C6H6)] (R=Me, Ph) with Me3NO in the presence of 1,3-cyclohexadiene or 1,4-cyclohexadiene yields the clusters [{Os4(CO)8(RCCR)(η6-C6H6)}2222-C6H8-1,3)] and [{Os4(CO)8(RCCR)(η6-C6H6)}2222-C6H8-1,4)], respectively. The molecular structure of [{Os4(CO)8(MeCCMe)(η6-C6H6)}2222-C6H8-1,3)] has been determined by single crystal X-ray diffraction, and represents the first example of two osmium cluster fragments linked by 1,3-cyclohexadiene through a μ222-bridge.
Keywords: Cluster; Osmium; Cyclohexadiene; Carbonyl; Crystal structure;

The reaction of CdCl2 with bis(2-pyridylmethyl)amino-4-butyric acid (Hpmab) leads to the formation of binuclear complex [(Hpmab)(Cl)CdII(μ-Cl)2CdII(Cl)(Hpmab)] (1). Complex 1 can be regarded as two distorted octahedrons sharing the basal edge that contain the bridging chloro ligands, in each of which resides at a center of inversion. Cyclic voltammetry of 1 gives one oxidation and two reduced processes.
Keywords: Crystal structure; Binuclear cadmium(II) complex; Bis(2-pyridylmethyl)amino-4-butyric acid; Bridged chlorides; Octahedral geometry;

Induced crystallization of polymeric Cd(II)-DMPYS assemblies (DMPYS=4,6-dimethyl-pyrimidine-2-thiolato): synthesis and chaining structures of α- and β-[Cd(DMPYS)2] n by Ernesto Schulz Lang; Gelson Manzoni de Oliveira; Gleison Antonio Casagrande; Ezequiel M Vázquez-López (1297-1301).
The reaction product of cadmium acetate dihydrate with 4,6-dimethyl-2-pyrimidinethiol (DMPYSH) in ethanol solubilizes by stirring with DMSO {(CH3)2SO} or ammonium diethyl dithiophosphate affording the title compounds α-(1) and β-[Cd(DMPYS)2] n (2). The slow evaporation of the ethanolic solutions allows the suitable crystallization of both polymers and their X-ray diffraction analysis. The complexes 1 and 2 crystallize in the space groups P21/c and Pca21, assembling polymeric, single chains along the crystallographic axis a (1) and b (2). The cadmium centers achieve a distorted octahedral coordination in the whole lattice with the support of four (in 1) and three (in 2) DMPYS molecules. Although in both compounds the anionic ligand DMPYS realizes μ-S and chelating S,N(ring) bonds, in 2 the bridging S-bonds are singly strengthened by two bidentate bridging bonds of the pyrimidine N-atoms. The polymeric lattice of both compounds is unknown up to date, and probably is matured by the slow splitting of the chelating DMSO and ammonium diethyl dithiophosphate from de Cd coordination sphere of the primary insoluble complexes.
Keywords: Cadmium-supramolecular assemblies; Polymeric cadmium chains; Cd-[4,6-dimethyl-pyrimidine-2-thiolato]-complexes;

Preparation and characterization of NiO nanofibres via an electrospinning technique by Hongyu Guan; Changlu Shao; Shangbin Wen; Bin Chen; Jian Gong; Xinghua Yang (1302-1303).
Thin PVA/nickel acetate composite fibres were prepared by using sol–gel processing and electrospinning technique. After calcinations of the above precursor fibres, NiO nanofibres with a diameter of 50–150 nm could be successfully obtained. The fibres were characterized by SEM, FT-IR, WAXD, respectively. The results showed that the crystalline phase and morphology of NiO fibres were largely influenced by the calcination temperature.
Keywords: NiO nanofibres; PVA/nickel acetate composite; Electrospinning; PVA;

Two unusual copper complexes [Cu(Hnta)(afo)] (1) and [Cu3(nta)2(bpe)2(H2O)4] · bpe·10H2O (2) were synthesized and characterized. 1 displays a novel zigzag chain structure via tetradentate Hnta ligands and 2 forms two-dimensional network via hydrogen bonds interactions between the coordination water molecules and nta or free bpe ligands.
Keywords: Copper complex; Crystal structure; Nitrilotriacetate; 4,5-Diazafluoren-9-one; Hydrogen-bonding;

Approaches to bi- and trimetallic platinum and palladium complexes using the DPPEPM ligand by Padma Nair; Gordon K. Anderson; Nigam P. Rath (1307-1310).
Bis{(diphenylphosphinoethyl)phenylphosphino}methane (DPPEPM) reacts with [PtR2(cod)] in 1:1 ratio to give [PtR2(DPPEPM-PP)] (2a, R=Me; 2b, R=Ph), whereas with [PtCl2(cod)] or [PdCl2(cod)] it yields the ionic species [M(DPPEPM-PP)2]2+ (3 and 4). With [MClMe(cod)], the product is [MMe(DPPEPM-PPP)]+ (5, M=Pt; 6, M=Pd), in which one of the internal P atoms of the ligand is uncoordinated. These complexes undergo oxidation of the free P atom to give 7 and 8 on standing in solution. Complexes 2–4 may be used to construct bimetallic and trimetallic mixed metal complexes. The molecular structures of 7 and [PtMe2(μ-DPPEPM)PdCl2] (11) are reported.
Keywords: Platinum and palladium complexes; Crystal structure(s); Tetraphosphine ligands;

One novel polynuclear complex [Cu2(bpc)2(N3)4Ca(H2O)2Na2(H2O)2] n having three different transition and non-transition metal centres by Sutapa Sen; Chirantan Roy Choudhury; Nirmal Kumar Karan; Amitabha Datta; Samiran Mitra; R.K.Bhuban Singh; Volker Gramlich (1311-1314).
The complex [Cu2(bpc)2(N3)4Ca(H2O)2Na2(H2O)2] n (1) (bpc2−=2,2-bipyridyl-3,3-dicarboxylate) has been prepared and characterised by elemental analyses, spectroscopic and single crystal X-ray diffraction study. Single crystal X-ray analysis revealed a novel polynuclear complex containing three different metal centres such as an alkali metal (sodium), an alkaline earth metal (calcium) and a transition metal atom (copper) connected together by azide and carboxylato groups.
Keywords: Copper; Calcium; Sodium; BPC dianion; Crystal structure;

Synthesis and characterization of silver(I) complexes [AgL]2[BF4]2 and [Ag(OAc)L] [L=(CH2NHCOC2H4PPh2)2] by Yat Li; Ka-Fu Yung; Hoi-Shan Chan; Wing-Tak Wong; Wai-Kwok Wong; Man-Chung Tse (1315-1318).
The interaction of (CH2NHCOC2H4PPh2)2, L, with one equivalent of AgBF4 and AgOAc gave [AgL]2[BF4]2 1 and [Ag(OAc)L] 2, respectively. X-ray crystallographic studies showed that the ligand adopts a linear conformation in dimeric complex 1 and a bent conformation in polymeric complex 2. Both compounds exhibited temperature-dependent 31P{1H} NMR spectra.
Keywords: Silver(I) complex; Bis(ethylamidophosphine); Crystal structure; Temperature-dependent 31P{1H} NMR study;

Hydrothermal reactions of lead(II) salts with N-isobutylimino-bis(methylene-phosphonic acid), C4H9N(CH2PO3H2)2 (H4L), under different conditions lead to two new lead(II) diphosphonates, namely, a layered Pb10L2(HL)4 1, and Pb2L 2 with a microporous network structure.
Keywords: Hydrothermal synthesis; Porous material; Layer compound; Lead(II) diphosphonates; Crystal structure;

Coordination assembling of nickel tetrathiooxalate on surface of CdS nanocrystals by Lin Guo; Jie Dai; Guo-Qing Bian; Ding-Xian Jia; Qin-Yu Zhu; Jia-Sheng Zhang (1323-1325).
Layer-by-layer assembled poly (nickel tetrathiooxalate, [Ni (TTO)]) on surface of CdS nanocrystals was characterized by IR, TEM and XPS spectra. The room temperature conductivity (lg  σ RT) of the CdS samples changes from 10−9 to 10−4 S cm−1 with increasing of the number of [Ni (TTO)] layers from 0 to 18.
Keywords: Surface-modification; Cadmium sulfide; Coordination assembling; Tetrathiooxalate;

A novel crystalline solid, [Cu(II)2(O2CPh)4(2,5-dmpyz)] n (2,5-dmpyz = 2,5-dimethyl-pyrazine), was synthesized and characterized by single-crystal X-ray diffraction analysis. The compound demonstrates multistep phase transition induced by CO2 adsorption, which readily obeys the ClausiusClapeyron equation in terms of the set of partial pressures of CO2 and transition temperatures.
Keywords: Dinuclear Cu complex; Coordination polymer; Phase transition; Crystal structure; Carbon dioxide;

Polymer-assisted hydrothermal synthesis of trigonal selenium nanorod bundles by Zhenghua Wang; Xiangying Chen; Jianwei Liu; Xiaogang Yang; Yitai Qian (1329-1331).
Uniform trigonal selenium (t-Se) nanorod bundles were synthesized by using Na2SeSO3 as reactant via a polymer-assisted hydrothermal method at 180 °C. The products were analyzed by using X-ray powder diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy. The probable formation mechanism was discussed.
Keywords: Nanomaterials; Surfactant; Hydrothermal synthesis; Semiconductors;

The first 1-D double-helical-chain coordination polymer, [(H2O)Cu(BPDC)] (2,2-biphenyldicarboxylate), based upon the binuclear square pyramidal copper(II)-pair motifs has been synthesized under hydrothermal conditions and characterized by single crystal X-ray diffraction technique. [(H2O)Cu(BPDC)] crystallized in orthorhombic crystal system, space group Cmca with unit cell dimensions a=21.073(6) Å, b=7.118(2) Å and c=17.670(5) Å, Z=8.
Keywords: Coordination polymer; One-dimensional structure; Hydrothermal reaction; Helical chain; Binuclear copper; 2,2-Biphenyldicarboxylate;

Iron(III) complexes with phenolate ligands (m-cresolate and tyrosinate) undergo a redox photolysis in aqueous solution upon phenolate → Fe(III) ligand-to-metal charge transfer excitation. At λ irr=577 nm the quantum yields of Fe(II) formation are approximately φ=10−4.
Keywords: Electronic spectra; Charge transfer; Photochemistry; Iron complexes; Tyrosine; Phenol;

A novel supermolecule [HgBr2(ptz)]2  · HgBr2 (ptz=phenothiazine) with uncoordinated inorganic salt HgBr2 presented in a 1D chain was prepared. The bulky ligand phenothiazine has unusual coordination mode with large steric inhibition perpendicular to the chain direction. The uncoordinated HgBr2 molecule was stabilized by multiple weak Hg⋯Br interactions and the whole structure was also stabilized by strong π–π interactions and N–H⋯Br hydrogen bonds to form 2D network.
Keywords: Supermolecule; Coordination mode; 1D chain; Photoluminescence;

A novel linear-chain material with [Pt(terpy)Cl]+ and [Pt(8-QNS)2] (8-QNS=8-quinolinethiolate) moieties shows sandwiched stacking via alternative Pt(II)⋯Pt(II) or Pt(II)⋯S and π⋯π interactions.A novel linear-chain material, [Pt(8-QNS)2][Pt(terpy)Cl]2(ClO4)2 (8-QNS=8-quinolinethiolate; terpy=2,2:6,2″-terpyridine), has been serendipitously isolated and characterized by a crystallographic study. The title compound composed of alternative cationic [Pt(terpy)Cl]+ pairs and [Pt(8-QNS)2] moieties is formed by an interesting rearrangement process, and it shows sandwiched stacking via alternative Pt(II)⋯Pt(II) or Pt(II)⋯S and π⋯π interactions.

The reaction of the sodium salt of the monoanion, nido-[2,3-(Si(CH3)3)2-2,3-C2B4H5], with (chloromethyl)dimethylchlorosilane in a 1:1 molar ratio produced the B(cage)-substituted cluster, nido-5-ClCH2Si(CH3)2-2,3-(Si(CH3)3)2-2,3-C2B4H5 (1), in 81% yield. This product (1) was reacted further with the lithium salt of [closo-1-R-1,2-C2B10H10] monoanion (R=Me, Ph) to give the novel linked and mixed C2B4/C2B10 carborane species, 1-Me-2-[5-SiMe2CH2-2,3-(SiMe3)2-2,3-C2B4H5]-1,2-C2B10H10 (2), 1-Ph-2-[5-SiMe2CH2-2,3-(SiMe3)2-2,3-C2B4H5]-1,2-C2B10H10 (3), in yields of 76% and 81%, respectively.

A novel metal–organic coordination polymer [Fe(phen)(ipt)] n 1 has been hydrothermally synthesized and structurally characterized. Compound 1 exhibits a novel neutral cross double-helical structure composed of left-handed and right-handed helical chains.
Keywords: Coordination polymer; Helical structure; Hydrothermal synthesis; Crystal structure;