Inorganic Chemistry Communications (v.3, #2)

Reaction of Mo2Cl4(dppm)2 with excess [n-Bu4N][CN] produces [Bu4N]2[Mo2 II,II(CN)6(dppm)2]·2(CH3CN)·2(C6H6) (1) the first example of an edge-sharing bioctahedral compound of Mo(II), that upon exposure to air oxidizes to the mixed valence analog [Bu4N][Mo2 II,III(CN)6(dppm)2]·2(H2O)·2(CH3CN) (2).
Keywords: Dimolybdenum(II,II) complex; Dimolybdenum(II,III) complex; Cyanide complexes; Crystal structures;

The oxidation of cobalt(II) chelate complexes [CoY]2−, where Y=edta (ethylenediaminetetraacetate), pdta (1,2-propanediaminetetraacetate) and cydta (trans-1,2-cyclohexanediaminetetraacetate), by [Co(mal)3]3− (mal=malonate) was catalyzed by chiral [Co(en)3]3+ to yield optically active products with the enantiomeric excesses which increase with increasing concentration of chiral [Co(en)3]3+. Substituents on the ethylenediamine backbone of [CoY]2− had significant effects on the sign and the magnitude in the stereoselectivity. The results are interpreted in terms of a chiral induction mechanism in which the ion pair between [CoY]2− and chiral [Co(en)3]3+ is stereoselectively oxidized by [Co(mal)3]3−. A model is proposed for the relative orientation of oxidant, reductant, and catalysis complexes.
Keywords: Chiral induction; Electron transfer reaction; Stereoselectivity; Anion–anion interactions;

In the reaction of Cu(CH3CO2)2·H2O with diethylenetriamine in equimolar proportion in ethanol in the presence of a slight excess of NaX, the nuclearity of the product is found to depend on the size of the non-coordinating anion X; the larger the anion, the lower the tendency of polymerisation in the counter cation.
Keywords: Crystal structures; Copper(II) complexes; Copper(II) dimer; Acetato bridged complexes;

Synthesis, structures, and conformational analysis of dibenzodioxadisilocins by Masaru Yoshida; Midori Goto; Fusae Nakanishi (59-61).
Novel dibenzodioxadisilocins were prepared using a dehalogenative coupling reaction between (2,6-dichlorophenoxy)t-butyldimethylsilane and dimethyldichlorosilane with magnesium via an intramolecular 1,3-anionic rearrangement of the silyl group. Their structures were unequivocally confirmed by X-ray crystallography. For a comparison with the X-ray data, molecular orbital calculations on the conformations of the organosilicon macrocyclics were also carried out.
Keywords: Heterocycle; Dibenzodioxadisilocin; X-ray crystallography; Molecular orbital calculation;

The complex bis{(μ-chloro)-chloro-[(N-diethylaminothiocarbonyl)benzimido-O-methyl ester-S]mercury(II)} was prepared by the reaction of HgCl2 with N-(diethylaminothiocarbonyl)benzimido-O-methyl ester. The compound has been characterised by FAB mass spectrometry, IR spectroscopy and NMR spectroscopy. The dimeric structure was established crystallographically: space group P-1, a=9.3296(4), b=9.5298(2), c=11.4615(2) Å, α=71.9930(10), β=88.8600(10), γ=65.0150(10)°, Z=1. Each mercury atom takes a tetragonal distorted geometry and is coordinated by two bridging chloride atoms, one terminal chloride atom and one thiocarbonyl sulfur atom of the ligand. The compound is the first example of a chloro-bridged mercury(II) complex of a ligand with a thiourea moiety; the bridge can be designated as symmetric.
Keywords: Crystal structures; Mercury complexes; Chloro-bridged complexes; Thiourea complexes;

A bis(μ-carboxylato-O)-bridged dinuclear zinc(II) complex of [(4-methyl-5-imidazol-1-yl)methylidene]-β-alanine has been synthesized and structurally characterized, in which the μ-carboxylato-O bridge and the metal–metal separation (3.263(4) Å) resemble those in serine/threonine protein phosphatase-1 (PP1).
Keywords: Crystal structures; [(4-Methyl-5-imidazol-1-yl)methylidene]-β-alanine; Zinc; Metalloenzyme model compound;

The mononuclear compound [Ru(terpy)L], where H2L is 2,6-bis(1,2,4-triazol-3-yl)pyridine, shows an emission lifetime of 65 ns, about 300 times longer than that observed for the parent [Ru(terpy)3]2+ complex.
Keywords: Luminescence; Ruthenium complexes; Terpyridine complexes; Triazole complexes;

Mixing of aqueous solutions of the cluster anion [Re6Se8(CN)6]4− and Zn2+ in the presence of acetic acid (pH 3) leads to precipitation of (H3O)2Zn3[Re6Se8(CN)6]2·20H2O having a three dimensional framework of {Zn3[Re6Se8(CN)6]2}2− formed by Re–CN–Zn covalent interactions. This framework occupies only 41.9% of the unit cell volume. The rest of the space is filled by disordered water molecules and hydroxonium cations.
Keywords: Crystal structures; Cluster compounds; Rhenium complexes; Cyanides complexes; Porosity; Polymers;

Organometallic diaqua complexes of palladium(II) by José Ruiz; Félix Florenciano; Consuelo Vicente; M. Carmen Ramı́rez de Arellano; Gregorio López (73-75).
The protonation of [(C6F5)LPd(μ-OH)2PdL(C6F5)] by triflic acid (CF3SO3H) results in the formation of the diaqua complexes [Pd(C6F5)L(H2O)2][CF3SO3] (L=PPh3 (1) or AsPh3 (2)). The crystal structure of 2 was elucidated by X-ray diffraction analysis revealing the presence of tetrameric units involving hydrogen bonds.
Keywords: Palladium complexes; Aqua complexes; Crystal structures;

Counter cation-controlled air oxidation of manganese derivatives of tetrachlorocatechol by Rafael Ruiz; Andrea Caneschi; Dante Gatteschi; Claudio Sangregorio; Lorenzo Sorace; Miguel Vázquez (76-79).
The potassium salt of the triphenylphosphine oxide adduct of bis(tetrachlorocatecholate)manganese(III) complex reacts with O2 in the presence of K+-sequestering agents at room temperature in MeCN resulting in the formation of the corresponding MnIV-tris(catecholate) species.
Keywords: Catecholato complexes; Hypervalent compounds; Manganese; O–O activation; Oxygenation; Potassium;

Oxidation of [Cp*RuH(dppf)] (1), dppf=1,1′-bis(diphenylphosphino)ferrocene, and [(Cym)RuCl(dppf)](PF6) (2), Cym=p-cymene, occurs at ruthenium for 1 but yields a ferrocenium species for compound 2.
Keywords: EPR; Ferrocene compounds; Oxidation; Ruthenium complexes; Spectroelectrochemistry;

A mononuclear copper(II) complex of a protonated unsymmetrical dinucleating Schiff base ligand by Harry Adams; David E. Fenton; Shabana R. Haque; Sharon E. Spey (83-86).
Reaction of the unsymmetrical and potentially dinucleating Schiff base ligand HL1 with copper(II) salts has given mono- and dinuclear metal complexes. The structure of a mononuclear complex of diprotonated HL1, [Cu(H2L1)(OH2)](ClO4)3·H2O·CH3OH, has been determined.
Keywords: Crystal structures; Copper(II) complexes; Schiff base; Unsymmetrical dinucleating ligand;

A bimetallic building block with terminal free ligands designed for molecular wire synthesis by Nicole L. Wagner; Frank E. Laib; Dennis W. Bennett (87-90).
The reaction between (dppe)2W(N2)2 and CNC6H4NC produces (dppe)2CNC6H4NCWCNC6H4NCWCNC6H4NC(dppe)2, a dimer containing electron-rich metal centers, a protective sheath of organic ligands, and terminal free isocyanide groups.
Keywords: Tungsten complexes; Isocyanide complexes;