The Ox2013;H···O, Ox2013;H···N and Cx2013;H···O hydrogen bonds in 1,4-dimethylpiperazine mono-betaine monohydrate
摘要
1,4-Dimethylpiperazine mono-betaine (1-carboxymethyl-1,4-dimethylpiperazinium inner salt, MBPZ) crystallizes as monohydrate. The crystals are orthorhombic, space group Pccn. Two MBPZ molecules and two water molecules form a cyclic oligomer, (MBPZ·H2O)2. The Ox2013;H···O and Ox2013;H···N hydrogen bonds are of 2.769(1) and 2.902(1) Å, respectively. The dimers interact with the neighboring molecules through the Cx2013;H···O hydrogen bonds of 3.234(1) Å. The piperazine ring assumes a chair conformation with the N(4)x2013;CH3 and N+(1)x2013;CH2COO− groups in the equatorial position and the N+(1)x2013;CH3 group in the axial one. The FTIR spectrum is compared with that calculated by the B3LYP/6-31G(d,p) level of theory.