Supramolecular structure of the 1:2 complex of 1,4-dimethylpiperazine mono-betaine with squaric acid
| dc.contributor.author | Dega-Szafran, Zofia | |
| dc.contributor.author | Katrusiak, Andrzej | |
| dc.contributor.author | Komasa, Anna | |
| dc.contributor.author | Szafran, Mirosław | |
| dc.date.accessioned | 2018-03-22T14:09:15Z | |
| dc.date.available | 2018-03-22T14:09:15Z | |
| dc.date.issued | 2013-07-01 | |
| dc.description.abstract | The 1: 2 complex of 1,4-dimethylpiperazine mono-betaine (MBPZ) with squaric acid (H(2)SQ) has been characterised by single-crystal X-ray analysis, FTIR and NMR spectroscopies, and by DFT calculations. The crystals are monoclinic, space group P2(1)/c. Two MBPZ cations and four hydrogen squarate anions (HSQ(-)) are linked by strong O(1)=H center dot center dot center dot O(13) (2.525(4) angstrom), O(14)-H center dot center dot center dot O(21) (2.511(4) angstrom) and N(4)-H center dot center dot center dot O(23) (2.607(3)angstrom) hydrogen bonds into a cyclamer R-6(6)(38). In turn, the cyclamers are linked into a helix C-4(4)(20) through two O(24)-H center dot center dot center dot O(11) hydrogen bonds of 2.516(4)angstrom. The piperazinium ring has a chair conformation with N(4)-CH3 and N(1)-CH2COOH substituents in the equatorial positions, and N(1)-CH3 in the axial position. The FTIR spectrum is consistent with the crystal data. Two models of the 1: 2 complex of MBPZ with H(2)SQ have been optimised at the B3LYP/6-311++G(d,p) level of theory and have been used to calculate harmonic IR frequencies. One of the models (2) is dominated by electrostatic attraction between NH(4)(+) and HSQ(-), whereas in the other (3) squaric acid interacts with a zwitterionic MBPZ through the O-H center dot center dot center dot O and O-H center dot center dot center dot N hydrogen bonds. | pl |
| dc.identifier.citation | SUPRAMOLECULAR CHEMISTRY 25 (7) 432-440 | pl |
| dc.identifier.issn | 1061-0278 | |
| dc.identifier.uri | http://hdl.handle.net/10593/22314 | |
| dc.language.iso | eng | pl |
| dc.rights | info:eu-repo/semantics/openAccess | pl |
| dc.subject | X-ray diffraction | pl |
| dc.subject | electrostatic interactions | pl |
| dc.subject | DFT calculations | pl |
| dc.subject | FTIR and NMR spectroscopy | pl |
| dc.subject | hydrogen bonds | pl |
| dc.subject | squaric acid | pl |
| dc.title | Supramolecular structure of the 1:2 complex of 1,4-dimethylpiperazine mono-betaine with squaric acid | pl |
| dc.type | Artykuł | pl |