Vibrational study, phase transitions and electrical properties of 4-benzylpyridinium monohydrogenselenate

The title compound C6H5CH2C5H4NH+·HSeO4− crystallizes in the orthorhombic system with the space group Pbca and the following unit cell dimensions: a=27.449(5) Å; b=10.821(6) Å and c=8.830(1) Å.The structure consists of infinite parallel two-dimensional planes built of HSeO4− anions and C6H5CH2C5H4NH+ cations mutually.Differential scanning calorimetry study on 4-benzylpyridinium monohydrogen-selenate was carried out. A high temperature second order phase transition at 363 K was found and characterized by electric measurements. The Raman of polycrystalline sample has been recorded at different temperature between 297 and 373 K.The conductivity relaxation parameters associated with some H+ conduction have been determined from an analysis of the M′′/M′′max spectrum measured in a wide temperature range. An appearance of the superionic phase transition in 4-BSe is closely related to a liberation or even a rotation increase of HSeO4− groups with heating.