Joel D. Oliver

The crystal structure of -(diphenylphosphino) phenyl--1,2-dicarbomethoxyethenyltriphenylphosphineplatinum.

Abstract The structure of o -(diphenylphosphino) phenyl- cis -1,2-dicarbomethoxyethenyltriphenylphosphineplatinum,(Ph3P)[Ph2P(C6H4)]Pt- cis -(CO2MeCCHCO2Me), has been determined by single crystal X-ray diffraction methods. The crystals are triclinic, space group P 1 , two molecules per unit cell with dimensions a = 12.560(1), b = 13.600(1), c = 11.452(1) A, α = 110.01(1), β = 97.58(1), and γ = 91.03(1)°. A calculated density of 1.57 g cm−3 for two formula units per cell is consistent with the measured value of 1.56(2) g cm−3. The coordination about the platinum atom is square-planar with the two phosphine ligands oriented cis with respect to one another. The σ-bonded vinyl group also possesses cis stereochemistry. The geometry of the four-atom metallocyclic ring in this compound is compared to those of metallocyclobutene and platinacyclobutane complexes. The average PtP bond length is 2.330(2) A and the observed PtC bond lengths are 2.059(8) and 2.026(8) A. These bond lengths are discussed in terms of the trans -influence. Full-matrix least-squares refinement has yielded R = 0.047 (0.048 for weighted R) based on the 5208 reflections whose intensities are significantly above background (Inet ≥ 10 counts s−1).

The crystal structure of methyl[hydrotris(pyrazol-1-yl)borato]carbonylplatinum(II)

Abstract The crystal structure of methyl[hydrotris(pyrazol-1-yl)borato]carbonylplatinum(II) has been determined by single crystal X-ray diffraction techniques. Crystals of (CH3)[HB(C3N2H3)3]Pt(CO) are monoclinic, P21/c,a = 14.416(1), b = 7.951(1), c = 12.990(1) A, β = 104.35(1)°. The observed density (2.04 g cm−3) agrees favorably with that calculated (2.08 g cm−3) on the basis of four molecules per unit cell. The structure was solved by the Patterson method and has been refined by full-matrix least squares techniques to a final R1 value of 0.041 (R2 = 0.039) for 2124 reflections. The compound is square-planar with only two of the three pyrazolyl groups coordinated to the platinum atom. The platinum atom is located 0.015(1) A above the plane defined by the four donor atoms. The uncoordinated pyrazolyl group is disordered with the shortest intramolecular distance involving platinum and any non-hydrogen atom of that ring being 3.30(1) A. The PtN distances are 2.036(9) and 2.064(9) A; PtC(methyl) and PtC(carbonyl) distances are 2.070(12) and 1.798(16) A, respectively.

Rotational isomerism in methallyl iodide

Abstract Infrared spectra were obtained for methallyl iodide (3-iodo-2-methylpropene)in the liquid state at room temperature and for the vapor state at a series of temperatures. The spectra show that this compound exists in only one form in the neat liquid at room temperature. In the vapor, the concentration of a second form becomes appreciable at elevated temperatures. The energy difference between the two forms in the vapor state is about 4 Kcal/mole. Some of the infrared bands were assigned.

Sterically crowded platinum(II) phosphine cations

Abstract Cationic platinum(II) hydrides [HPtL 2 L′] + (L = phosphines) have been prepared and the ligand steric effects studied; the crystal and molecular structure of trans -[PtH(PCy 3 ) 2 PPh 3 ] PF 6 is described.

X-Ray structure of a novel bidentate polypyrazolylborate complex: carbonyl[hydrodotris(pyrazol-1-yl)borato]methylplatinum

The crystal structure of a bidentate hydridotris(pyrazol-1-yl)borate complex with platinum(II) is reported.