title: Amitriptylinium picrate: conformational disorder.
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.
authors.affiliation: Department of Studies in Chemistry, University of Mysore, Manasagangotri, Mysore 570 006, India.
authors.forename: S
authors.initials: S
authors.lastname: Bindya
authors.forename: Wing-Tak
authors.initials: WT
authors.lastname: Wong
authors.forename: M A
authors.initials: MA
authors.lastname: Ashok
authors.forename: H S
authors.initials: HS
authors.lastname: Yathirajan
authors.forename: R S
authors.initials: RS
authors.lastname: Rathore
mesh_terms: D000639:Amitriptyline / Q000737:chemistry*; D000929:Antidepressive Agents, Tricyclic / Q000737:chemistry; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008968:Molecular Conformation; D010851:Picrates / Q000737:chemistry*
chemical_list: D000929:Antidepressive Agents, Tricyclic; D010851:Picrates; D000639:Amitriptyline