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

Abstract

1-[ N-(2-bromophenyl)]naphthaldimine (C 17H 12NOBr) ( 1) was synthesised and its crystal structure was determined. The compound 1 is orthorhombic, space group P2 12 12 1 with a=12.653(2), b=13.7311(14), c=7.9799(12) A ̊ , V=1386.4(4) A ̊ 3, Z=4, D c =1.563 g cm −3, μ( Mo K α )=2.959 mm −1, R=0.032 for 499 reflections I>2 σ( I)]. There is an intramolecular hydrogen bond of distance 2.473(3) Å 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 θ (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, 1H NMR and UV measurements in solution and in the solid state were carried out.