Structure of an inclusive compound of bis(piperidinium-4-carboxylate)hydrogen semi-tartrate with water and methanol studied by X-ray diffraction, NMR, FTIR and DFT methods
✍ Scribed by Z. Dega-Szafran; Z. Fojud; A. Katrusiak; M. Szafran
- Publisher
- Elsevier Science
- Year
- 2009
- Tongue
- English
- Weight
- 976 KB
- Volume
- 928
- Category
- Article
- ISSN
- 0022-2860
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✦ Synopsis
The complex consisting of two piperidine-4-carboxylic acid, L-tartaric acid, water and methanol molecules has been synthesized and characterized by X-ray diffraction, 1 H, 13 C NMR, 13 C CP MAS NMR, FTIR spectra and DFT calculations. The title complex is composed of the following units: piperidinium-4-carboxylate (P4C), piperidinium-4-carboxylic acid (P4CH), semi-tartrate anion (TA), water and methanol; it crystallizes in orthorhombic space group P2 1 2 1 2 1 . TA anions form infinite chains through the COOHÁÁÁOOC hydrogen bond of 2.503(5) Å. The zwitterionic P4C molecules are linked by the N + HÁÁÁOOC hydrogen bond of 2.780(5) Å into chains. The P4CH cation is a bridge between the TA and P4C chains. P4CH and P4C form a homoconjugated cation through the COOHÁÁÁOOC hydrogen bonds of 2.559(5) Å. Water interacts with TA and P4CH, while methanol interacts only with water. In the optimized molecule of the (P4C) 2 HÁTAÁH 2 OÁHOCH 3 complex, the components form a cyclic oligomer through four O-HÁÁÁO and four N-HÁÁÁO hydrogen bonds. The 1 H and 13 C NMR spectra elucidate the structure of the title complex in the aqueous solution. The 13 C CP MAS NMR spectrum is consistent with the X-ray results. The FTIR spectrum confirms a very complex structure of the title compound.