Intramolecular hydrogen bonding and tautomerism in 1-[N-(4-bromophenyl)]aminomethylidene-2(1H) naphthalenone

1-[N-(4-bromophenyl)]aminomethylidene-2(1H)naphthalenone (C17H12NOBr) (1) w as synthesized and its crystal structure was determined. Compound (1) is mo noclinic, space group P2(1)/n with a = 4.808(1) Angstrom, b = 20.617(1) Ang strom, c = 13.750(1) Angstrom, beta = 93.004(1)degrees, = 1361.11(3) Angstr om (3), Z = 4, D-c = 1.592 g.cm(-3), mu (Mo K-alpha) = 3.014 mm(-1), R = 0. 051 for 1013 reflections [I > 2 sigma (I)]. There is a strong intramolecula r hydrogen bond of distance 2.544(2) Angstrom between the hydroxyl oxygen a tom and imine nitrogen atom, the hydrogen atom essentially being bonded to the nitrogen atom, The title molecule is not planar. X-ray crystal structur e determination reveals the existence of the keto (or predominantly keto) t automer in (1). Spectra of compound (1) were observed by IR and NMR, and UV -visible spectra of (1) were studied in different solvents and acidic media .