The results of mild-infrared spectroscopy and X-ray studies of the third member of the 4-n-alkyl-4'-isothiocyanatobiphenyl (nTCB) homologous series are presented. Correspondence between the phase transitions observed by means of the IR spectroscopy and those given by the adiabatic calorimetry was found. The structure of five solid phases was obtained by X-ray measurements. IR spectroscopic and X-ray data give the arguments supporting the identification of the glass of smectic E phase. Assignment of the IR vibrational bands, in the smectic E, in the glass of smectic E, and in one of the crystalline phases, with help of the hybrid B3LYP/6-311++G(d,f) functional calculations is presented.