Structural Chemistry & Crystallography Communication

Sarcosinium and Betainium Picrates

Reactions of sarcosine (N-methylglycine) and betaine (N-trimethylglycine) with picric acid in aqueous media were studied in comparison with previously studied reaction of glycine with picric acid. In contrast to glycine, where glycine glycinium picrate salt with dimeric cation is formed at both 2:1 and 1:1 molar ratios, in cases of sarcosine and betaine reactions at both 2:1 and 1:1 molar ratios lead to formation of sarcosinium picrate and betainium picrate. Crystal and molecular structures of sarcosinium picrate and betainium picrate were determined by single crystal X-ray diffraction analysis at 200 K. Both salts crystallized in monoclinic system (space groups P21/c and C2/c respectively). In both cases asymmetric units contain one formula unit and carboxyl groups of cations form hydrogen bonds with phenolic oxygen atoms of picrate anions with O···O distances 2.5861(13) Å and 2.5265(13) Å respectively. Similarity and dissimilarity of two structures are analyzed and discussed. Vibrational (infrared and Raman) spectra of both salts were recorded and discussed.

Author(s):

Petrosyan AM, Ghazaryan VV, Giester G and Fleck M

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