Crystal Structure of N-Methyl-3-t-isopropyl-r-2,c-6-diphenylpiperidin-4-one

N-Methyl-3-t-isopropyl-r-2,c-6-diphenylpiperidin-4-one (NMIDPPO), crystallizes in monoclinic space group P21/c with a = 16.666(6), b = 12.349(5), c = 18.778(7)A; β = 111.74(1)°, V = 3590(2)A3, Z = 8, Dcal = 1.138 Mg/m3. The structure was solved by direct methods and refined by full-matrix least-squares procedures to a final R-value of 0.0556 for 5078 observed reflections. There are two crystallographically independent molecules in the asymmetric unit. The piperidine rings in both molecules adopt the chair conformation with the planar phenyl rings substituted equatorially at the 2,6 positions. The C-H…O type of intermolecular hydrogen bonds and C-H…π weak interactions stabilize the molecules in the unit cell in addition to the van der Waals forces.