Amitriptylinium picrate: conformational disorder

Acta Crystallogr C. 2007 Sep;63(Pt 9):o546-8. doi: 10.1107/S0108270107037468. Epub 2007 Aug 17.

Abstract

In the structure of the title salt [systematic name: 3-(10,11-dihydro-5H-dibenzo[a,d][7]annulen-5-ylidene)-N,N-dimethylpropan-1-aminium 2,4,6-trinitrophenolate] of a tricyclic antidepressant, C(20)H(24)N+.C(6)H(2)N(3)O(7)-, the dimethylaminopropyl subunit possesses a classical static conformational disorder. The central cycloheptadiene ring adopts a bent conformation that is intermediate between boat and chair forms, leading to a butterfly shape for the hetero-tricyclic moiety. In a complementary fashion, donors from amitriptyline and acceptors from picrate form intermolecular C-H...O hydrogen bonds and N-H...O salt bridges. These hydrogen bonds cluster amitriptyline and picrate ions into a closed R4(4)(36) hetero-tetramer, whereas intermolecular C-H...pi interactions between amitriptyline ions cluster them into homo-dimers. Significant pi-pi stacking interactions are also observed between aromatic rings of amitriptyline and picrate, and these, combined with the C-H...pi interactions, associate molecules into linear arrays along the [111] direction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amitriptyline / chemistry*
  • Antidepressive Agents, Tricyclic / chemistry
  • Crystallography, X-Ray
  • Hydrogen Bonding
  • Models, Molecular
  • Molecular Conformation
  • Picrates / chemistry*

Substances

  • Antidepressive Agents, Tricyclic
  • Picrates
  • Amitriptyline