Crystal structure and conformational analysis of 1-[N-(2-bromophenyl)]naphthaldimine

1-[N-(2-bromophenyl)]naphthaldimine (C17H12NOBr) (1) was synthesised and its crystal structure was determined. The compound 1 is orthorhombic, space group P2(1)2(1)2(1) with a = 12.653(2), b = 13.7311(14), c = 7.9799(12) Angstrom, V = 1386.4(4) Angstrom(3), Z = 4, D-c = 1.563 g cm(-3), mu(Mo K-alpha) = 2.959 mm(-1), R = 0.032 for 499 reflections I > 2sigma(I)]. There is an intramolecular hydrogen bond of distance 2.473(3) A between the hydroxyl oxygen atom and imine nitrogen atom, the hydrogen atom essentially being bonded to the oxygen atom. Minimum energy conformation was calculated as a function of torsion angle theta(C10-C11-N1-C12) varied every 5 degrees. The optimized geometry of the crystal structure corresponding to the non-planar conformation is the most stable conformation in all calculations. The results strongly indicate that the minimum energy conformation is primarily determined by hydrogen-hydrogen repulsions between the ortho-hydrogen atoms on the aldehyde rings. Complementary IR, H-1 NMR and UV measurements in solution and in the solid state were carried out. (C) 2003 Elsevier B.V. All rights reserved.