Crystal and molecular structural studies of (±)- and meso-bivalvane

Abstract

The crystal and molecular structures of (±)- and meso-bivalvane have been determined by single-crystal three-dimensional X-ray diffraction methods. The (±)-hydrocarbon (2) crystallizes in the monoclinic space group P2₁/c with lattice parameters a= 9.779(1), b= 17.219(2), c= 9.635(1)Å, and β= 99.89(1)°. The structure was refined to R 0.049 for 1 853 observed reflections. The meso-hydrocarbon (4) is also monoclinic, space group P2₁/n, with Z= 2 in a cell of dimensions a= 6.377(1), b= 6.306(1), c= 19.553(2)Å, and β= 90.87(1)°. The molecule spans a crystallographic inversion centre. Refinement converged at R 0.039 for 928 observed reflections. Both bivalvanes adopt strain-free extended conformations, the triquanane-part structures of which appear to be regular in their geometry.