On the Absence of Doubly Bonded Te═O Groups in TeO Glass.

Tellurium oxide clusters (TeO) were investigated through density functional theory to gain information on the structure of TeO glass. Among a large number of stable conformers studied, a cyclic, nonsymmetric structure was optimized without terminal Te═O double bonds. The dimer of this structure, (TeO), gives calculated Raman and infrared spectra in very good agreement with the experimental ones, with its total pair distribution function being also in agreement with results of neutron and high-energy X-ray diffraction studies.

Short-Range Disorder in TeO Melt and Glass.

High-resolution X-ray pair distribution functions for molten and glassy TeO reveal coordination numbers ≈ 4. However, distinct from the known α-, β-, and γ-TeO polymorphs, there is considerable short-range disorder such that no clear cutoff distance between bonded and nonbonded interactions exists. We suggest that this is similar to disorder in δ-TeO and arises from a broad distribution of asymmetric Te-O-Te bridges, something that we observe becomes increasingly asymmetric with increasing liquid temperature.

Tetrathiomolybdate Complexes of Rhodium(I) with Molybdenum-Rhodium Interactions.

The synthesis and characterization of the tetrathiomolybdatorhodium(I) monoanionic complexes [L2Rh(μ-S)2MoS2](-) (L = CO (3), P(OPh)3 (4), P(O-o-Tol)3 (P(o-CH3C6H4)3; 5), P(OMe)3 (6), P(OEt)3 (7), P(O-i-Pr)3 (8); L2 = COD (1,5-cyclooctadiene; 2), cis-dppen (cis-Ph2PCH═CHPPh2; 9), dppe (Ph2PCH2CH2PPh2; 10), dppb (Ph2P(CH2)4PPh2; 11)) is presented. The complex 2 (NEt4(+) salt) was characterized by X-ray diffraction analysis. A detailed DFT study of the electronic structures of 2-4 and 6-8 has revealed the existence of extended electron delocalization over the four-membered Rh(μ-S)2Mo ring and hence the possibility of electronic communication between the metal centers.

Theoretical elucidation of a classic reaction: protonation of the quadruple bond of the octachlorodimolybdate(II,II) [Mo2Cl8]4- anion.

The protonation reaction of the unbridged quadruple metal-metal bond of [Mo(2)Cl(8)](4-) anion producing the triply bonded hydride [Mo(2)(μ-H)(μ-Cl)(2)Cl(6)](3-) is studied by accurate Density Functional Theory computations. The reactant, product, stable intermediates, and transition states are located on the potential energy surface. The water solvent is explicitly included in the calculations.