Preparation, Crystal Structure, Vibrational Spectra, and Thermal Behavior of N, N-Dimethylpiperazinium(2+) Hydrogen Selenite

The X-ray structural analysis of N,Nʹ-dimethylpiperazinium(2+) hydrogen selenite has been carried out. The substance crystallizes in the orthorhombic space group Pbcn, a=14.682(2), b=6.4910(10), c=13.065(2) ?; V=1245.1(3) ?3, Z=8, R= 0.0234 for 2135 observed reflections. The cations of trans-N, Nʹ-dimethylpiperazinium(2+) in the chair conformation are arranged roughly plane-parallel above one another. Hydrogen selenite anions linked by H-bonds form infinite chains, which are interconnected with N,Nʹ-dimethylpiperazinium(2+) groups by N–H···O hydrogen bonds. The FTIR and FT Raman spectra of natural and deuterated compounds were recorded and interpreted. The FTIR spectra were studied down to a temperature of 90 K. The thermoanalytical properties were studied by the TG, DTG, and DTA methods in the 293–573 K temperature range. DSC measurements were carried out in the 95–403 K temperature range. No thermal effect indicating phase transition was observed in this temperature region.