STRUCTURE OF THE TRIPHENYLBOROXIN-N,N-DIMETHYLETHYLENEDIAMINE 1-1 ADDUCT

C22H27B3N2O3, M(r) = 399.9, orthorhombic, P2(1)2(1)2(1), a = 13.429 (3), b = 14.125 (2), c = 11.964 (3) angstrom, V = 2269 (2) angstrom 3, Z = 4, D(x) = 1.17 g cm-3, lambda(Mo K-alpha) = 0.71073 angstrom, mu = 0.7 cm-1, F(000) = 848, T = 294 K, R = 0.044 for 1279 observed reflections. The B3O3 ring is almost planar but a small fold distortion exists across the ring to yield a shallow boat conformation. Two B atoms have sp2 trigonal planar coordination and the third achieves sp3 tetrahedral coordination by bonding to the NH2 group of N,N-dimethylethylenediamine. The Me2N group does not interact with any B atom. Three distinct B-O distances are observed in the B3O3 ring with mean values B(sp2)-O[B(sp3)] 1.338 (5), B(sp2)-O[B(sp2)] 1.381 (5) and B(sp3)-O[B(sp2)] 1.460 (6) angstrom.