DIFFERENCE-DENSITY DISTRIBUTION OF A PRISMANE DERIVATIVE

Dimethyl propella[3]prismane dicarboxylate (dimethyl 2,10).0(3,9).0(9, 11)]hexadeca-2,10-dicarboxylate), C20H26O4, M(r) = 330.4, Pnma, a = 15 .129 (1), b = 14.853 (1), c = 7.768 (1) angstrom, V = 1745.7 (5) angst rom3, Z = 4, D(x) = 1.26 g cm-3, lambda(Mo Kalpha) = 0.71071 angstrom, mu = 0.0805 mm-1, F(000) = 712, T = 95 K. The steric strain of this p olycyclic compound is indicated by bent bonds. From the difference ele ctron-density distribution we determined a bending of 19-degrees for t he bonds in the plane of the three-membered ring and a bending of 7.5- degrees in the planes of the four-membered rings.