Z. Dega‐Szafran, A. Katrusiak, M. Szafran
Sep 17, 2008
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0
Influential Citations
9
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Journal
Journal of Molecular Structure
Abstract
Abstract 1,4-Dimethylpiperazine di-betaine, DBPZ (1,4-dicarboxymethyl-1,4-dimethylpiperazinium inner salt) crystallizes with two molecules of water. The crystals are triclinic, space group P 1 ¯ , a = 6.181(2) A, b = 6.2600(18) A, c = 8.869(2) A, α = 97.50(2)°, β = 94.40(2)°, γ = 112.48(3)°, Z = 1, R = 0.0418. Double water-molecules bridges link the DBPZ molecules into infinite chains by two sequences of O–H⋯O hydrogen bonds of 2.771(2) and 2.810(2) A. The piperazine ring has a chair conformation with the methyl groups in the axial positions and the CH 2 COO − groups in the equatorial ones. The FTIR spectra of DBPZ(H 2 O) 2 and DBPZ(D 2 O) 2 are interpreted and the assignment of bands to the corresponding vibrations is proposed on the grounds of the spectra calculated by the B3LYP/6-31G(d,p) level of theory. The DBPZ(H 2 O) 2 hydrogen-bonded complex is more stable by 18.5 kcal/mol than anhydrous DBPZ.