Structural Investigations Of Benzo[C]Cinnoline Derivatives .1. Structures Of 1-Piperidinobenzo[C]Cinnoline And 3-Piperidinobenzo[C]Cinnoline

Abstract

(1) C17H17N3, M(r) = 263.34, monoclinic, P2(1)/c, a = 8.473 (3), b = 11.556 (4), c = 13.933 (6) angstrom, beta = 92.09 (3)-degrees, V = 1363.3 (3) angstrom-3, Z = 4, D(m) = 1.27, D(x) = 1.283 g cm-3, lambda-(Cu K-alpha) = 1.54180 angstrom, mu = 5.689 cm-1, F(000) = 560, T = 293 K, R = 0.070 for 1701 observed reflections [I less-than-or-equal-to 3-sigma-(I)]. (2) C-17H17N3, M(r) = 263.34, triclinic, P1BAR, a = 8.646 (3), b = 13.064 (4), c = 13.338 (4) angstrom, alpha = 100.91 (3), beta = 99.50 (3), gamma = 106.03 (3)-degrees, V = 1383.5 (4) angstrom 3, Z = 4, D(m) = 1.25, D(x) = 1.264 g cm-3, lambda-(Cu K-alpha) = 1.54180 angstrom, mu = 5.606 cm-1, F(000) = 560, T = 293 K, R = 0.059 for 2040 observed reflections [I greater-than-or-equal-to 3-sigma-(I)]. The rings in the benzo[c]cinnoline skeleton of (1) and (2) are close to planar, while the skeleton itself is non-planar. The dihedral angles between the rings in the benzo[c]cinnoline skeleton are between 6.59 (6) and 14.32 (6)-degrees in (1) and between 1.0 (1) and 3.4 (1)-degrees in the more planar (2). The difference is caused by steric interactions between the piperidino and benzo[c]cinnoline groups in (1). These interactions also cause the piperidino group in (1) to rotate out of the plane of the benzo[c]cinnoline group, while in (2) the whole molecule is close to planar. The piperidino group adopts a slightly distorted chair conformation in both (1) and (2).