William R. Robinson

The crystal structure of the complex of triphenylarsine oxide with tetrachlorocatechol; an adduct stabilized by chelating hydrogen bonds

The 1/1 triphenylarsine oxide adduct of tetrachlorocatechol crystallizes in the orthorhombic space group Pbca with a =15.07±0.02, b =18.82±0.03, and c =16.53±0.02A. An observed density of 1.58g/cm 3 and calculated density of 1.62g/cm 3 indicated the presence of 8 molecules per unit cell. 1219 reflections above background were collected with Cu-Kα radiation using a manual diffractometer of Weissenberg geometry. The structure was solved by Patterson and Fourier techniques and refined by least squares methods (As, O, Cl anisotropic; C, H isotropic) to a conventional R of 0.070 and a weighted R of 0.041. The structure consists of triphenylarsine oxide and tetrachlorocatechol moieties hydrogen bonded together to give discrete monomeric adducts. The arsine oxide oxygen (O As ) is hydrogen bonded symmetrically to the two OH groups of the catechol with an O-O As -O angle of 65.4(4)° and O As -O distances averaging 2.616(11)A. The dimensions of the triphenylarsine oxide and tetrachlorocatechol are equivalent to those observed in other similar compounds except that the configuration of the phenyl rings with respect to the As-O bond is quite distorted. This distortion results from the alternate packing of approximately parallel phenyl and catechol rings along the a axis.

A facile synthesis of small-ion ternary molybdenum sulfides

The reaction of lithiated molybdenum disulfide with hydrogen at 1000°C leads to Mo6S8 in high yield. This material reacts with n-butyl lithium giving Li4Mo6S8, which can be converted to other small-ion ternary molybdenum sulfides (Chevrel phases) by ion exchange in molten salts. The pseudo binary Mo6S6Br2 gives Li2Mo6S6Br2 with n-butyl lithium.

Some Characteristics of Infrared and Raman Spectra and Bonding of a Series of Lanthanide Complexes with L-Proline

Abstract The crystalline lanthanide complexes (except Ce and Pm) with proline were synthesized. The general formula of [Ln(Pro)2(H2O)4]3(ClO4)3 of the complexes were obtained from chemical analysis, elemental analysis, TG-DTA analysis and electrical conductivity. Infrared spectra reveal a considerable shift of the symmetric co2 stretching mode from lower to higher energies in the lanthanide complexes and a decrease of Δv(Δv=vcoo- as -vcoo- s) from 212 cm−1 in proline to about 167 cm−1 in the complexes. The peak mean 405cm−1 in the Raman spectra varies with the total orbital angular smomentum of the lanthanide ions in the ground states, exhibiting a profile of an “inclined w”. These spectral features in the IR and Raman spectra were regarded as strong evidences of Ln-O bonding. The peak near 405cm1 was assigned as the Ln-O stretch modes.

A new class of diosmium(IV) complexes containing both oxide and carboxylate bridges

The reactions of the OsVI complexes OsO2X2(PR3)2(X = Cl or Br) with refluxing carboxylic acids produce a new class of osmium dimers of the type Os2(µ-O)(µ-O2CR)2X4(PR3)2 whose structural details have been confirmed by an X-ray diffraction study of Os2(µ-O2CCH3)2Cl4(PPh3)2.

Stability of thallium(I) transition metal carbonyls

Thallium(I) derivatives of metal carbonyl anions are generally stable with weakly basic anions whereas disproportionation to thallium(III) derivatives occurs with more strongly basic anions.

Crystal structure of a binuclear five-co-ordinate copper(II) complex with tetra-amine macrocyclic ligands and single chloride bridge

Hydrogen bonding between tet b and perchlorate ions stabilizes [Cu(tet b)]2Cl3+ which contains trigonal bipyramidal co-ordinate Cu2+ with an almost linear Cu–Cl–Cu bridge and with the tet b ligand in its most stable, folded form.