Crystallographic characterization of the first reported crystalline form of the potent hallucinogen (R)-2-amino-1-(8-bromobenzo[1,2-b;5,4-b']difuran-4-yl)propane or `bromodragonfly': the 1:1 anhydrous proton-transfer compound with 3,5-dinitrosalicylic acid

Abstract

The 1:1 proton-transfer compound of the potent substituted amphetamine hallucinogen (R)-2-amino-1-(8-bromo­benzo[1,2-b;5,4-b']difuran-4-yl)propane (common trivial name `bromo­dragonfly') with 3,5-dinitro­salicylic acid, namely 1-(8-bromo­benzo[1,2-b;5,4-b']difuran-4-yl)propan-2-aminium 2-carb­oxy-4,6-dinitro­phenolate, C13H13BrNO2+·C7H3N2O7-, forms hydrogen-bonded cation-anion chain substructures comprising undulating head-to-tail anion chains formed through C(8) carboxyl-nitro O-H...O associations and incorporating the aminium groups of the cations. The intra­chain cation-anion hydrogen-bonding associations feature proximal cyclic R33(8) inter­actions involving both an N+-H...Ophenolate and the carboxyl-nitro O-H...O associations and aromatic [pi]-[pi] ring inter­actions [minimum ring centroid separation = 3.566 (2) Å]. A lateral hydrogen-bonding inter­action between the third aminium H atom and a carboxyl O-atom acceptor links the chain substructures, giving a two-dimensional sheet structure. This determination represents the first of any form of this compound and is in the (R) absolute configuration. The atypical crystal stability is attributed both to the hydrogen-bonded chain substructures provided by the anions, which accommodate the aminium proton-donor groups of the cations and give crosslinking, and to the presence of the cation-anion aromatic ring [pi]-[pi] inter­actions.