PHOSPHORUS CHEMICAL-SHIFT ANISOTROPIES IN SOLID TRIPHENYL PHOSPHITE AND MER,TRANS-BIS(TRIPHENYL PHOSPHITE)TRICARBONYL(THIOCARBONYL)CHROMIUM(0), CR(CO)3(CS)[P(OPH)3]2

The P-31 chemical shift anisotropies have been measured for solid triphenyl phosphite, P(OPh)3 (at 128 K), and the complex with the tricarbonyl(thiocarbonyl)chromium(0) moiety, mer,trans-Cr(CO)3(CS)[P(OPh)3]2 (at 298 K). The shift tensor is axially symmetric in the phosphite ligand, and the major change upon complexation occurs for the components of the shift tensor perpendicular to the bond direction. The crystal structure of the chromium complex has been determined by single-crystal X-ray diffraction at 293 K. The complex crystallizes in the centric P2(1)/n (No. 14) space group with cell constants (at 20-degrees-C) a = 8.166(3) angstrom, b = 11.530(2) angstrom, c = 20.183(2) angstrom, beta = 96.43(1)degrees, and Z = 2. The molecule is disordered on a crystallographically imposed inversion center so that the thiocarbonyl ligand is superimposed on the trans carbonyl ligand (50:50).