Hydrogen-bonded molecular salts of reduced benzothiazole derivatives with carboxylates: a robust (8) supramolecular motif (even when disordered)
| Autor: | Shaibah, Mohammed A. E., Sagar, Belakavadi K., Yathirajan, Hemmige S., Cordes, David B., Slawin, Alexandra M. Z., Harrison, William T. A. |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: | |
| Zdroj: | Acta Crystallographica Section E: Crystallographic Communications |
| ISSN: | 2056-9890 |
| Popis: | The syntheses and structures of five molecular salts of protonated 4,4,7,7-tetramethyl-3a,5,6,7a-tetrahydrobenzothiazol-2-ylamine (C11H19N2S+) with different deprotonated carboxylic acids (4-methylbenzoic acid, 4-bromobenzoic acid, 3,5-dinitrobenzoic acid, fumaric acid and succinic acid) are reported·In every case, the cation protonation occurs at the N atom of the thiazole ring and the six-membered ring adopts a half-chair conformation (in some cases, the deviating methylene groups are disordered over two sets of sites). The C—N bond lengths of the nominal –NH+=C—NH2 fragment of the cation are indistinguishable, indicating a significant contribution of the –NH—C=N+H2 resonance form to the structure. The syntheses and structures of five molecular salts of protonated 4,4,7,7-tetramethyl-3a,5,6,7a-tetrahydrobenzothiazol-2-ylamine (C11H19N2S+) with different deprotonated carboxylic acids (4-methylbenzoic acid, 4-bromobenzoic acid, 3,5-dinitrobenzoic acid, fumaric acid and succinic acid) are reported, namely 2-amino-4,4,7,7-tetramethyl-4,5,6,7-tetrahydro-1,3-benzothiazol-3-ium 4-methylbenzoate, C11H19N2S+·C8H7O2 −, (I), 2-amino-4,4,7,7-tetramethyl-4,5,6,7-tetrahydro-1,3-benzothiazol-3-ium 4-bromobenzoate, C11H19N2S+·C7H4BrO2 −, (II), 2-amino-4,4,7,7-tetramethyl-4,5,6,7-tetrahydro-1,3-benzothiazol-3-ium 3,5-dinitrobenzoate, C11H19N2S+·C7H3N2O6 −, (III), bis(2-amino-4,4,7,7-tetramethyl-4,5,6,7-tetrahydro-1,3-benzothiazol-3-ium) fumarate, 2C11H19N2S+·C4H2O4 2−,(IV), and the 1:1 co-crystal of bis(2-amino-4,4,7,7-tetramethyl-4,5,6,7-tetrahydro-1,3-benzothiazol-3-ium) succinate and 2-amino-4,4,7,7-tetramethyl-4,5,6,7-tetrahydro-1,3-benzothiazol-3-ium hydrogen succinate 4,4,7,7-tetramethyl-3a,5,6,7a-tetrahydrobenzothiazol-2-ylamine, 1.5C11H19N2S+·0.5C4H4O4 2−·0.5C4H5O4 −. 0.5C11H18N2S, (V). In every case, the cation protonation occurs at the N atom of the thiazole ring and the six-membered ring adopts a half-chair conformation (in some cases, the deviating methylene groups are disordered over two sets of sites). The C—N bond lengths of the nominal –NH+=C—NH2 fragment of the cation are indistinguishable, indicating a significant contribution of the –NH—C=N+H2 resonance form to the structure. The packing for (I)–(V) features a robust local R 2 2(8) loop motif in which the cation forms two near-linear N—H⋯O hydrogen bonds from the N+—H group and syn H atom of the amine group to the carboxylate group of an adjacent anion [(V) shows disorder of one of these bonds over N—H⋯O and N⋯H—O contributors but the same R 2 2(8) loop results for both disorder components]. The anti H atom of the –NH2 group also forms an N—H⋯O hydrogen bond, which results in [001] chains in (I) and (II), isolated centrosymmetric tetramers in (III) and [100] chains in (IV) and (V). Hirshfeld fingerprint plots and contact percentages for the different types of contacts of the cations are discussed. |
| Databáze: | OpenAIRE |
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