Donald D. Titus

The solid state structure of triphenyltelluronium cyanate-chloroform()

Three-dimensional X-ray crystal structure analysis shows that the organotelluronium salt, triphenyltelluronium cyanate-chloroform(), exists as a tetramer in the solid state with both end-to-end and terminally bridging NCO groups. The oligomer is predominantly ionic with tellurium—nitrogen and tellurium—oxygen distances significantly shorter than respective van der Waals distances. Refinement of the structure, based on 3817 reflections collected by automatic diffractometry, converged to a conventional R factor of 4.9% and a weighted R factor of 4.2%. Crystal data for Ph3Te(NCO) · CHCl3 are as follows: a = 12.083(6)A, b = 12.900(12)A, c = 13.878(10)A, α = 95.83(7)°, β = 103.47(7)°γ = 98.87(6)°, V = 1901A3 (temperature = 23°C) and Z = 4.

The molecular characterization of an organotellurium “anhydride”, bis(isothiocyanatodiphenyltellurium(IV)) oxide, ((C6H5)2TeNCS)2O

Abstract The first structural characterization of a member of the class of compounds R2Te(X)OTe(X)R2 is reported. Three-dimensional X-ray crystal structure analysis shows that (Ph2TeNCS)2O is molecular in the solid state. The molecule has two-fold symmetry, with the rotation axis passing through the oxygen atom and bisecting the Te-O-Te angle. The ether-like Te-O-Te moiety is bent, 121.7(4)°, with a Te-O distance of 1.985(4)A. An intermolecular Te-S contact at 3.416(3)A completes a square-pyramidal geometry around the tellurium atom, and links the molecules into chains running parallel to the c axis. The Te-N bond distance, 2.40(1)A, is considerably longer than the sum of covalent radii, indicating a tendency toward ionic character in the bond. Refinement of the structure, based on 1662 reflections collected by automatic diffractometry, converged to a conventional R factor of 6.5% and a weighted R factor of 6.2%. Crystal data for (Ph2TeNCS)2O are as follows: space group C2/c, a = 18.540(5)A, b = 13.487(6)A, c = 10.934(4)A, β = 94.72(2)°, V = 2725A3 (23 ± 1°C) and Z = 4.

The crystal structure of triphenylselenonium isothiocyanate

Abstract Three dimensional X-ray crystal structure analysis shows that triphenylselenonium isothiocyanate consists of discrete ion pairs in the solid state with each pair having an Se-N contact (3.197(4)A) and SeC(NCS) contact (3.260(5)A) significantly shorter than the respective van der Waals distance. These short distances are accompanied by acute SeNC (83.0(3)°) and SeCN (76.8(3)°) angles, and suggest a weak interaction between the triphenylselenonium cation and the π-electron system of isothiocyanate anion. Ph 3 Se(NCS) is neither isomorphous nor isostructural with Ph 3 Te(NCS). Refinement of the structure, based on 3126 reflections collected by automatic diffractometry, converged to a conventional R factor of 5.5% and a weighted R factor of 5.2%. Crystal data for Ph 3 Se(NCS) are as follows: a = 12.417(4)A, b = 11.556(5)A, c = 12.633(3)A, β = 113.17(2)°, V = 1666A 3 (23 ± 2°C) and Z = 4; space group P2 1 /c.

Preparation of the dimethylphenyltelluronium and triphynltelluronium ions by direct phenylation with NaBPh4

New reactions are described for the formation of CTe bonds by the use of an organoborate. Accordingly, dimethyltellurium dichloride, Me2TeCl2, and diphenyltellurium dichloride, Ph2TeCl2, undergo direct and facile phenylation reactions with sodium tetraphenylborate at room temperature in methanol and water, respectively, to produce dimethylphenyltelluronium and triphenyltelluronium tetraphenylborate, respectively. Tellurium tetrachloride in benzene undergoes triarylation with excess NaBPh4 to yield Ph3Te+BPh4-.

X-Ray structure of triphenyltelluronium thiocyanate: an oligomeric organotelluronium salt

X-Ray structural results shows that the solid organo-tellurium salt Ph3Te(NCS) exists as discrete dimers and tetramers formed from bridging NCS groups with intra Te ⋯ N and Te ⋯ S distances significantly shorter than respective van der Waals distances.

The crystal and molecular structure of hydridotetrakis(diethyl phenylphosphonite)cobalt(I)

An X-ray structure determination of the title compound shows that the co-ordination about the cobalt atom is approximately trigonal bipyramidal; n.m.r. data indicate that the complex is non-rigid in solution.