Chiral discriminations of complexes with D3 symmetry. Molecular structure and crystal-packing mode of (–)589-tris[(–)-O,O′-1(R),2(R)-dimethylethylene dithiophosphato]chromium(III), [Cr{(–)bdtp}3]

Abstract

The molecular structure and crystal-packing mode of [Cr{(–)bdtp}₃][bdtp =O,O′-1(R),2(R)-dimethylethylene dithiophosphate] have been determined from single-crystal X-ray diffraction data and refined by full-matrix least-squares methods to R 0.0435. The optically active crystal has unit-cell dimensions a= 11.699(1), b= 12.738(2), c= 16.827(2)Å, space group P2₁2₁2₁ and Z= 4. The ligand has two ring planes: an inner four-membered chelate ring and an outer five-membered ring. The complex exhibits approximate D₃ symmetry and the three inner rings and the three outer rings each form a propeller of opposite handedness. The crystal-packing mode and the chiral recognitions have been compared with those of D₃ tris(chelate)metal complexes involving a single propeller system.