title: Crystal structure and Hirshfeld surface analysis of 1-carb-oxy-2-(3,4-di-hydroxy-phen-yl)ethan-1-aminium chloride 2-ammonio-3-(3,4-di-hydroxy-phen-yl)propano-ate: a new polymorph of l-dopa HCl and isotypic with its bromide counterpart.
abstract: The title mol-ecular salt, C9H12NO4+·Cl-·C9H11NO4, is isotypic with that of the bromide counterpart [Kathiravanet al.(2016 ▸).Acta Cryst.E72, 1544-1548]. The title salt is a second monoclinic polymorph of the l-dopa HCl structure reported earlier in the monoclinic space groupP21[Jandacek & Earle (1971 ▸).Acta Cryst.B27, 841-845; Mostad & Rømming (1974 ▸).Acta Chemica Scand.B28, 1161-1168]. In the title compound, monoclinic space groupI2, one of the dopa mol-ecules has a positive charge with a protonated α-amino group and the α-carb-oxy-lic acid group uncharged, while the second dopa mol-ecule has a neutral charge, the α-amino group is protonated and the α-carb-oxy-lic acid is deprotonated. In the previously reported form, a single dopa mol-ecule is observed in which the α-amino group is protonated and the α-carb-oxy-lic acid group is uncharged. The invariant and variations of various types of inter-molecular inter-actions present in these two forms of dopa HCl structures are discussed with the aid of two-dimensional fingerprint plots.
authors.affiliation: Crystal Growth Laboratory, PG and Research Department of Physics, Periyar EVR Government College (Autonomous), Tiruchirappalli 620 023, India.
authors.forename: Perumal
authors.initials: P
authors.lastname: Kathiravan
authors.affiliation: Crystal Growth Laboratory, PG and Research Department of Physics, Periyar EVR Government College (Autonomous), Tiruchirappalli 620 023, India.
authors.forename: Thangavelu
authors.initials: T
authors.lastname: Balakrishnan
authors.affiliation: Laboratorio de Polímeros, Centro de Química Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla (BUAP), Complejo de Ciencias, ICUAP, Edif. 103H, 22 Sur y San Claudio, CP 72570 Puebla, Puebla, Mexico.
authors.forename: Perumal
authors.initials: P
authors.lastname: Venkatesan
authors.affiliation: Crystal Growth and Thin Film Laboratory, Department of Physics and Nanotechnology, SRM University, Kattankulathur 603 203, India.
authors.forename: Kandasamy
authors.initials: K
authors.lastname: Ramamurthi
authors.affiliation: Laboratorio de Polímeros, Centro de Química Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla (BUAP), Complejo de Ciencias, ICUAP, Edif. 103H, 22 Sur y San Claudio, CP 72570 Puebla, Puebla, Mexico.
authors.forename: María Judith
authors.initials: MJ
authors.lastname: Percino
authors.affiliation: Biomolecular Crystallography Laboratory, Department of Bioinformatics, School of Chemical and Biotechnology, SASTRA University, Thanjavur 613 401, India.
authors.forename: Subbiah
authors.initials: S
authors.lastname: Thamotharan
keywords: Hirshfeld surfaces; crystal structure; cyclic N—H⋯Cl hydrogen bonds; l-dopa