Structure Reports Online

Volume 66, Part 2 (February 2010)

organic compounds

Acta Cryst. (2010). E66, o366-o367 [ doi:10.1107/S1600536810000280 ]

Trimipraminium maleate

J. P. Jasinski, R. J. Butcher, Q. N. M. Hakim Al-Arique, H. S. Yathirajan and B. Narayana

Abstract: The title compound [systematic name: 3-(10,11-dihydro-5H-dibenzo[b,f]azepin-5-yl)-N,N,2-trimethylpropan-1-aminium hydrogen maleate], C₂₀H₂₇N₂⁺·C₄H₃O₄^-, a maleate salt of trimipramine, crystallizes with four independent cation-anion pairs in the asymmetric unit. The trimipramine cation contains a seven-membered azepine ring with two fused benzene rings whose mean planes are separated by 51.7 (1)°. Intermolecular N-HO and intramolecular O-HO hydrogen bonds pack the ions into chains along [101]. Additional weak intermolecular C-HO interactions help to influence the twist angles of the mean planes of the benzene rings fused to the azepine ring in the cation. A geometry-optimized MOPAC AM1 theoretical calculation supports these observations.