Inorganic Chemistry Communications (v.7, #9)

Contents list (iii-iv).

Density functional molecular orbital calculations at the BP86 level were performed to investigate rotational barrier of vinylidene ligand in the model complexes OsHCl(C=CH2)(L)2 (L = PMe3, PH3, PF3). Results of calculations indicate that the rotational barrier increases with the increasing π-accepting ability of phosphine. This result has been explained on the basis of the extent of π-interaction between metal and vinylidene ligand in the complexes.
Keywords: Vinylidene complexes; DFT study; Phosphine; Osmium;

Zinc oxide (ZnO) with flowerlike and needlelike shapes has been successfully synthesized by a simple microwave-assisted solution phase approach using an imidazolium salt 1-n-butyl-3-methyl imidazolium tetrafluoroborate ([BMIM]BF4) (an ionic liquid). By controlling experimental conditions, exclusive ZnO needles or flowers could be synthesized in a short period of time (5 or 10 min).
Keywords: Zinc oxide; Ionic liquids; Microwave-heating; Shape-control;

A new approach to novel homobimetallic palladium complexes by D. Taher; B. Walfort; H. Lang (1006-1009).
Mononuclear trans-(PPh3)2Pd(I)(C6H4-4-I) (3), which is accessible by the oxidative addition of C6H4-1,4-I2 (2) to (Ph3P)4Pd (1), reacts with [AgOTf] (4) in a 1:1 molar ratio to give trans-(PPh3)2Pd(C6H4-4-I)(OTf) (5). Complex 5 affords on treatment with 0.5 equivalents of 4,4′-dicyanobiphenyl (6) homobimetallic trans-[(PPh3)2(C6H4-4-I)Pd ← NC―C6H4]2(OTf)2 (7). The latter species rearranges to give trans-[(PPh3)2(C6H4-4-PPh3)Pd ← NC―C6H4]2(OTf)4 (8) and [(PPh3)(C6H4-4-PPh3)Pd(μ-I)]2(OTf)2 (9), respectively. A possible mechanism for the formation of 8 and 9 will be presented. The solid-state structure of 8 is reported. In 8 two [trans-(PPh3)(C6H4-4-PPh3)Pd]2+ fragments are bridged by the 4,4′-dicyanobiphenyl unit.
Keywords: Palladium; Oxidative addition; Phosphane; Homobimetallic; 4,4′-dicyanobiphenyl; X-ray structure;

Azomethine ylides, generated from the reactions of different aldehydes (RCHO) 1ad with sarcosine, reacted with endohedral metallofullerenes M@C82 (M = Gd, Y) affording multi-substituted metallofulleropyrrolidines. The formation of these derivatives was confirmed by matrix assisted laser desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometry and some of them were isolated by recycling HPLC.
Keywords: Cycloaddition; Endohedral metallofullerenes; Fullerenes; Fulleropyrrolidines;

One-step fabrication of selenium and tellurium tubular structures by Ai-Miao Qin; Yue-Ping Fang; Cheng-Yong Su (1014-1016).
Single-crystal Se and Te tubular structures have been synthesized in one step by a hydrothermal method and characterized by means of X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and selected-area electron diffraction (SAED). The hollow prismatic morphology of the tubular structures has been revealed and explained based on the nucleation and growth mechanism of the highly anisotropic crystal structures of Se and Te.
Keywords: Hydrothermal synthesis; Selenium; Tellurium; Tubular structure;

Novel group 14 elements-bridged self-assembled supramolecules from pyrimidine derivatives and palladium ions by Yoshiyuki Miura; Masato Nanjo; Kunio Mochida; Takeaki Iwamoto; Mitsuo Kira (1017-1018).
A solvent-free complex of dimethyldi(5-pyrimidyl)silane with (ethylenediamine)palladium dinitrate in ratio of 1:3 afforded hitherto unknown three-dimensional, silicon-bridged, self-assembled, cage-like supramolecule via dative: bonding to the transition metal centers. The structure of the supramolecule was fully identified by spectroscopic methods and X-ray diffraction analysis. A germanium analogue was also prepared in the same way.
Keywords: Supramolecule; Pyrimidine derivatives; Heavier carbon homologues; X-ray diffraction;

Two new bis(pyridyl)terephthalate ligands were synthesized in good yields from the reaction of either 2-pyridylcarbinol or 2-pyridinepropanol with terephthaloyl chloride in the presence of triethylamine. Mixing these ligands with silver(I) salts resulted in the formation of crystalline helical polymeric complexes. In the complexation involving silver triflate, two separate structures were obtained, one of which contained water in the asymmetric unit.
Keywords: Coordination polymer; Helix; Silver; Pyridine;

The useful synthetic precursor [Re(CO)3(H2O)3]Br (1) may be prepared in nearly quantitative yield by refluxing [Re(CO)5]Br in H2O for 24 h. Upon concentrating the solution, compound 1 is isolated as a microcrystalline light green powder, which is soluble in water and polar organic solvents. Recrystallization from methanol affords [Re(CO)3(MeOH)2Br] (2), while recrystallization from acetonitrile provides the crystalline [Re(CO)3(CH3CN)2Br] (3). The lability of the aqua ligands of 1 is also manifested upon recrystallization from ethyl acetate/hexane, which yields [Re(CO)3(OH)]4  · 4H2O (4  · 4H2O). The reaction chemistry of 1 with dipyridylamine has been compared to that of the conventional starting material [NEt4]2[Re(CO)3Br3] and shown to produce a monophasic compound, free of contamination with NEt4Br. Crystal data: C7H6BrN2O3Re (3): orthorhombic Pnma, a  = 6.2289(3) Å, b  = 13.1323(7) Å, c  = 13.1700(7) Å, V  = 1077.3(1) Å3, D calc  = 2.665 g/cm3. C3H3O5Re (4  · 4H2O): tetragonal I-4, a  = 11.5964(3) Å, c  = 8.8764(4) Å, V  = 1193.67(7) Å3, D calc  = 3.397 g/cm3.
Keywords: {Re(CO)3}+1 core; Radiopharmaceuticals; ‘Aqua ion’ {Re(CO)3(H2O)3}+1;

[PPh4][Et4N]2[S2MoS2CuS2MoS2] (2b) has been synthesized by the reaction between [PPh4]2[S2MoS2CuCl] (2a) and [Et4N]2[MoS4] as a model of the heterometal sulfide core of an orange protein (ORP) isolated from the sulfate-reducing organism, Desulfovibrio gigas. 2a and 2b are structurally characterized by single crystal X-ray crystallography. Comparison of the structural data between ORP and 2b clearly suggests that the model complex ideally duplicates the reported structural features of the ORP metal cluster as analyzed by EXAFS. The Mo1⋯Cu⋯Mo2 angle in 2b significantly deviates from linearity (17°). This is related to the unequal bonding of the two chelated [MoS4]2− ligands to the central Cu as is revealed by unequal Cu–S and Mo–Sbr bond lengths in the X-ray structural data. The step-wise approach for the synthesis of 2a and 2b is essential as direct reaction of CuI, like other d10 metal ions, with [MoS4]2− led to the formation of high nuclearity cluster which thermodynamically is more favorable. The structural instability of 2b and also of ORP may reflect the inability of ORP to act as a structurally stable entity in a manner similar to that in copper–molybdenum antagonism. One oxidation peak potential (E pa  = 0.26 V vs. Ag/AgCl) of 2b is observed by cyclic voltammetry. 2b by iodine oxidation produced an EPR active CuII species [g  = 2.40, g  = 2.08, A  = 112 (104 cm−1), A  = 14 (104 cm−1)].
Keywords: Synthesis; Orange protein; Cu–Mo–S-Cluster; Crystal structure; Desulfovibrio gigas;

Supramolecular self-assembly of porphyrin–fluorescein hybrid with amino-porphyrinatocopper(II) and its fluorescence strengthening character by Jia-Zheng Lu; Jin-Wang Huang; Li-Fen Fan; Jie Liu; Xian-Li Chen; Liang-Nian Ji (1030-1033).
The supramolecular self-assembly of porphyrin–fluorescein hybrid (Fl-PPTPP) with copper(II) complexes of 5-(p-amino-phenyl)-10,15,20-triphenylporphyrin (p-APTPP), Cu(II)(p-APTPP), by carboxyl-amino type hydrogen-bonding was studied using ESMS, UV–Vis spectra and fluorescence spectroscopic titration. A novel fluorescence strengthening character was observed in a fluorescence spectroscopic titration experiment for Fl-PPTPP/Cu(II)(p-APTPP) system and the formation constant of (Fl-PPTPP)–Cu(II)(p-APTPP) supramolecular complex was determined from the fluorescence spectroscopic titration data.
Keywords: Porphyrin–fluorescein hybrid; Supramolecular self-assembly; Hydrogen-bonding; Amino-porphyrinatocopper(II); Fluorescence strengthening character;

Unusual magnetic property associated with a structural phase transition within a new ion-pair complex by Chun-Lin Ni; Dong-Bin Dang; Yi-Zhi Li; Zuan-Ru Yuan; Zhao-Ping Ni; Zheng-Fang Tian; Qing-Jin Meng (1034-1036).
A novel ion-pair complex, [BrbzPyNH2][Ni(mnt)2], where [BrbzPyNH2]+  = 1-(4′-bromobenzyl)-4-aminopyridinium and mnt2−  = maleonitriledithiolate, forms a completely segregated uniform stacking column with the Ni⋯Ni distance 3.952 Å and undergoes a magnetic phase transition from paramagnetism in the high-temperature (HT) phase to diamagnetism in the low-temperature (LT) phase at around 105 K.
Keywords: 1-(4′-bromobenzyl)-4-aminopyridinium; Bis(maleonitriledithiolate)nickelate(III) complex; X-ray structure; Magnetic phase transition;

Synthesis, crystal structure, and magnetic property of a novel 2D polymer [Co(PDC)(4,4-bpy)](CH3OH) by Chengzhi Xie; Baofeng Zhang; Xuanwen Liu; Xiaoqing Wang; Huizhong Kou; Guangqiu Shen; Dezhong Shen (1037-1040).
A novel cobalt complex {[Co(PDC)(4,4-bpy)] · (CH3OH)} n (H2PDC = pyridine-2,6-dicarboxylic acid; 4,4′-bpy = 4,4′-bipyridine) was synthesized and its crystal structure has been determined by X-ray diffraction. The complex has a two-dimensional (2D) layer polymeric structure, consisting of six-coordinated cobalt(II) units. Magnetic properties have been investigated in the range of 18–302 K assuming isolated Co(II) ions (without any coupling, J  = 0).
Keywords: Crystal structure; Cobalt complex; 2D infinite layer; Pyridine-2,6-dicarboxylic acid;

The polyoxomolybdate (Bu4N)2[Mo6O19] reacts with AgNO3 in methanol/dimethylformamide solution to give the complex {(Bu4N)2Ag2[Mo8O26]} n , which contains infinite chain of [Mo8O26]4− linked up only by a pair of Ag ions and displays attractive interactions between the two AgI ions.
Keywords: Polyoxometalate; Sandwich complex; Metal–metal interaction; Coordination mode;

Self-assembly of a hydrated chiral C2-symmetric bisferrocenylimine via C–H⋯π and N⋯H–O–H⋯N interactions by Vamsee Krishna Muppidi; Tin Htwe; P.S. Zacharias; Samudranil Pal (1045-1048).
The crystal structure of (1R, 2R)-bis(ferrocenylimine)cyclohexane reveals a helical structure due to self-assembling via C–H⋯π interactions. Hydrogen bonds involving the water molecules present in the crystal lattice and additional C–H⋯π interactions act as bridges between the parallel helices and a two-dimensional network is formed.
Keywords: Ferrocene; Schiff base; Chiral; Crystal structure; C–H⋯π interaction; Helical;

Ferrocenylmethylphosphines ligands in the palladium-catalysed synthesis of methyl propionate by Ian R. Butler; Paul K. Baker; Graham R. Eastham; Kevin M. Fortune; Peter N. Horton; Michael B. Hursthouse (1049-1052).
The synthesis of a range of novel ferrocenylmethylphosphanes ligands is described which have direct application in the palladium catalysed reaction of carbon monoxide, methanol and ethene to obtain methyl propionate, a key intermediate in the preparation of methylmethacrylate.
Keywords: Ferrocene; Catalyst; Methacrylate; Ligand;

A new nitrophenyldicarboxylate-bridged tetranuclear-copper complex combined with 1,10-phenanthroline, [Cu4(nbdc)4(phen)4(H2O)4] · 2H2O, has been synthesized and characterized, and it displayed intense fluorescent emissions. The compound crystallized in triclinic crystal system, space group, P 1 ¯ , a  = 10.9938(8), b  = 13.9064(10), c  = 13.9683(10) Å, α  = 99.770(1), β  = 97.198(1), γ  = 113.401(1)°, V  = 1887.1(2) Å3, Z  = 2.
Keywords: Tetranuclear-copper complex; Hydrogen bonds; Two-dimensional structure; 1,10-phenanthroline; Fluorescent emissions;

In the presence of the organic template molecule, 4-amino-3,5-bis(4-pyridyl)-1,2,4-triazole, a unique acentric coordination polymer based on linear 4,4′-bipyridine (bipy) bridging ligand, {[Cu(bipy)2.5(H2O)](ClO4)2  · (H2O) · (CH3OH)1.5} n (1), was obtained by the reaction of Cu(II) perchlorate with bipy in H2O/CH3OH medium. The bidendate bipy molecules bridge the CuII centers to form a 2-D bilayer framework with an 82  · 10 topology, and the monodendate bipy ligands, locating up and down each 2-D architecture, are involved in significant aromatic stacking interactions with the adjacent 2-D motifs, resulting in a 3-D porous network with large square channels for including the guest solvents and anions.
Keywords: Coordination polymer; Porous material; Aromatic stacking interactions; Organic template; Crystal structure;

Novel exo-binding mode of an amino alcohol producing a 2D coordination polymer with heterometallic tetranuclear repeating units by Elena A. Buvaylo; Vladimir N. Kokozay; Olga Yu. Vassilyeva; Brian W. Skelton (1061-1064).
A novel two-dimensional coordination polymer with Cd2Cu2 repeating units propagated through the ethanol functions of a monodeprotonated diethanolamine has been synthesized in the open-air reaction of zerovalent copper, cadmium chloride and the amino alcohol in methanol.
Keywords: Heterometallic complex; Coordination polymer; Zero-valent copper; Cadmium chloride; Diethanolamine; Crystal structure;

As part of our efforts to develop ruthenium nitrosyl compounds for use as nitric oxide delivery agents, a new six coordinate {RuNO}6 compound, [Ru(NO)(bpb)Cl] (bpb =  N,N′-bis(2-pyridinecarboxamide)-1,2-benzene dianion) was prepared from the reaction between [Ru(NO)Cl(H2O)2] and N,N′-bis(2-pyridine carboxamide)-1,2-benzene. We report here the characterization of this new compound by 1H, 13C, HH COSY, HMQC and HMBC NMR spectroscopy, IR spectroscopy (ν NO  = 1867 cm−1) and ESI-MS (M + Na+ 505.9).
Keywords: Ruthenium nitrosyl; Carboxamido ligands; {RuNO}6; Photodynamic therapy;

Structural characterization and SOD activity of copper–oxaprozinate by Sabari Dutta; Subhash Padhye; Vickie Mckee (1071-1074).
SOD activity of the diaryl substituted heterocyclic COX-2 inhibitor, viz. oxaprozin (2), is synergistically enhanced upon copper conjugation compared to analogous copper compounds of established COX-1 inhibitors like aspirin (1) and ibuprofen (3). A “paddle-wheel” structure is reported for the dimeric copper complex of oxaprozin.
Keywords: X-ray crystal structure; COX inhibitors; Oxaprozin; Copper conjugation; SOD activity;

A new ester substituted heteroscorpionate ligand by Simone Alidori; Maura Pellei; Claudio Pettinari; Carlo Santini; Brian W. Skelton; Allan H. White (1075-1077).
The new dihydrobis(3-carboxyethyl-5-methylpyrazolyl)borate ligand BpCOOET,Me is prepared as its potassium salt in kerosene solution, using ethyl 3-methylpyrazole-5-carboxylate and KBH4, through careful temperature control. BpCOOET,Me reacts with CuCl and PPh3 to yield the {Cu(BpCOOET,Me)PPh3} complex. BpCOOET,Me and {Cu(BpCOOET,Me)PPh3} have been fully characterized by elemental analyses and FT-IR in the solid state and by NMR (1H, 13C and 31P) spectroscopy and electrospray ionization mass spectrometry in solution. A single crystal structural characterization is reported for {Cu(BpCOOET,Me)PPh3}.
Keywords: Copper(I) complexes; Pyrazole; Scorpionate ligands; Crystal structure;

Half-sandwich halolanthanacarboranes of the “carbons adjacent” C2B4-carborane ligand systems: important synthons for new polyhedral cage constructs by Jianhui Wang; Chong Zheng; Ang Li; Christina L. Allard; Joanna L. Smith; Gauthami Arikatla; John A. Maguire; Narayan S. Hosmane (1078-1081).
The reaction of LnX3 (Ln = Ce, X = Br; Ln = Gd, Lu, X = Cl) with the “carbons adjacent” carborane monoanion, [2,3-(SiMe3)2-2,3-C2B4H5] in 1:2 molar ratio in anhydrous tetrahydrofuran (THF) produced the dimeric half-sandwich halolanthanacarboranes, [closo-1-(X)-1,1-(THF)2-2,3-(SiMe3)2-1-Ln(η5-C2B4H4)]2, in 72–92% yields along with one equivalent of the neutral nido-carborane precursor, 2,3-(SiMe3)2-2,3-C2B4H6. This reliable synthetic route avoided complications such as solvent degradation and oxide ion incorporation that give rise to large multi-lanthanacarborane clusters. This method produced the first isolated halolanthanacarborane half-sandwich in the C2B4-cage systems.
Keywords: Halolanthanacarborane; Half-sandwich complex; Cerium; Gadolinium; Lutetium; Carbons-Adjacent; closo-Metallacarborane; Organometallics; nido-carborane; Synthon;

Synthesis, structure and magnetic properties of the novel heteropolynuclear complex bridged by azido by Shi-Bin Wang; Guang-Ming Yang; Rong-Fang Li; Li-Cun Li; Dai-Zheng Liao (1082-1085).
Synthesis of the first heterometallic hexapolynuclear complex [(CuL)4Mn2(N3)4] · 2MeOH which is bridged by azido and macrocyclic oxamido bridge and especial the azido bridge links to two different metal ions, has been reported in this paper and the complex was characterised by low-temperature magnetic measurements.
Keywords: Macrocyclic complex; Azido bridge; Magnetic property; Crystal structure;