TY - JOUR

T1 - Unusual hydrogen bonding in L-cysteine hydrogen fluoride

AU - Minkov, V. S.

AU - Ghazaryan, V. V.

AU - Boldyreva, E. V.

AU - Petrosyan, A. M.

PY - 2015/8/1

Y1 - 2015/8/1

N2 - L-Cysteine hydrogen fluoride, or bis(l-cysteinium) difluoride-L-cysteine-hydrogen fluoride (1/1/1), 2C3H8NO2S+·2F-·C3H7NO2S·HF or L-Cys+(L-Cys⋯L-Cys+)F-(F-⋯H - F), provides the first example of a structure with cations of the 'triglycine sulfate' type, i.e. A+(A⋯A+) (where A and A+ are the zwitterionic and cationic states of an amino acid, respectively), without a doubly charged counter-ion. The salt crystallizes in the monoclinic system with the space group P21. The dimeric (L-Cys⋯L-Cys+) cation and the dimeric (F-⋯H - F) anion are formed via strong O - H⋯O or F - H⋯F hydrogen bonds, respectively, with very short O⋯O [2.4438 (19) Å] and F⋯F distances [2.2676 (17) Å]. The F⋯F distance is significantly shorter than in solid hydrogen fluoride. Additionally, there is another very short hydrogen bond, of O - H⋯F type, formed by a L-cysteinium cation and a fluoride ion. The corresponding O⋯F distance of 2.3412 (19) Å seems to be the shortest among O - H⋯F and F - H⋯O hydrogen bonds known to date. The single-crystal X-ray diffraction study was complemented by IR spectroscopy. Of special interest was the spectral region of vibrations related to the above-mentioned hydrogen bonds.

AB - L-Cysteine hydrogen fluoride, or bis(l-cysteinium) difluoride-L-cysteine-hydrogen fluoride (1/1/1), 2C3H8NO2S+·2F-·C3H7NO2S·HF or L-Cys+(L-Cys⋯L-Cys+)F-(F-⋯H - F), provides the first example of a structure with cations of the 'triglycine sulfate' type, i.e. A+(A⋯A+) (where A and A+ are the zwitterionic and cationic states of an amino acid, respectively), without a doubly charged counter-ion. The salt crystallizes in the monoclinic system with the space group P21. The dimeric (L-Cys⋯L-Cys+) cation and the dimeric (F-⋯H - F) anion are formed via strong O - H⋯O or F - H⋯F hydrogen bonds, respectively, with very short O⋯O [2.4438 (19) Å] and F⋯F distances [2.2676 (17) Å]. The F⋯F distance is significantly shorter than in solid hydrogen fluoride. Additionally, there is another very short hydrogen bond, of O - H⋯F type, formed by a L-cysteinium cation and a fluoride ion. The corresponding O⋯F distance of 2.3412 (19) Å seems to be the shortest among O - H⋯F and F - H⋯O hydrogen bonds known to date. The single-crystal X-ray diffraction study was complemented by IR spectroscopy. Of special interest was the spectral region of vibrations related to the above-mentioned hydrogen bonds.

KW - amino acid salt

KW - bond/angle distribution

KW - crystal structure

KW - dimeric cation

KW - IR spectroscopy

KW - L-cysteine hydrogen fluoride

KW - short hydrogen bonds

UR - http://www.scopus.com/inward/record.url?scp=84952783386&partnerID=8YFLogxK

U2 - 10.1107/S2053229615013601

DO - 10.1107/S2053229615013601

M3 - Article

C2 - 26243424

AN - SCOPUS:84952783386

VL - 71

SP - 733

EP - 741

JO - Acta Crystallographica Section C: Structural Chemistry

JF - Acta Crystallographica Section C: Structural Chemistry

SN - 2053-2296

ER -