title: Reinvestigation of L-tryptophan picrate: establishment of the existence of the L-tryptophan L-tryptophanium dimeric cation.
abstract: A crystal structure redetermination of the L-tryptophan picrate crystal previously studied by Ishida et al. (Chem. Pharm. Bull. 41 (1993) 433-438) showed that it comprises L-tryptophan L-tryptophanium dimeric cation, one picrate anion and picric acid. The O⋯O distance of the O-H⋯O hydrogen bond in the dimeric cation is equal to 2.470(6) Å. The infrared spectrum of the crystal was registered and analyzed. The infrared spectrum of the crystals contains a broad absorption band centered at ca. 1170 cm(-1), which is assigned to the stretching vibration of the O-H bond.
authors.affiliation: Institute of Applied Problems of Physics, NAS of Armenia, 25 Nersessyan Str., 0014 Yerevan, Armenia. aram.m.petrosyan@gmail.com
authors.forename: A M
authors.initials: AM
authors.lastname: Petrosyan
authors.forename: M
authors.initials: M
authors.lastname: Fleck
authors.forename: V V
authors.initials: VV
authors.lastname: Ghazaryan
mesh_terms: D000096:Acetone / Q000737:chemistry; D002412:Cations; D018360:Crystallography, X-Ray; D019281:Dimerization; D006860:Hydrogen Bonding; D008968:Molecular Conformation; D010851:Picrates / Q000737:chemistry*; D012996:Solutions; D013055:Spectrophotometry, Infrared; D055672:Static Electricity; D014364:Tryptophan / Q000737:chemistry*
chemical_list: D002412:Cations; D010851:Picrates; D012996:Solutions; D000096:Acetone; D014364:Tryptophan