Abstract: The heat capacities of samples were measured by Differential Scanning Calorimetry(DSC), using scanning enthalpy method. The accuracy of the heat capacity measurements was appoximately 1 per cent by the method. The heat capacities of bis(n-octadecylammonium) tetrachlorometal-iates (Ⅱ), (n-C_(18)H_(37)NH_3)_2MCl_4 (M=Mn, Zn; short notation C_(18)M), were measured from 190 to 410 K. The enthalpies and entropies of the solid-solid phase transitions for C_(18)M were calculated. The selected thermodynamic functions were given at intervals of 5 K from 190 to 410 K.

Key words: Scanning enthalpy method, Heat capacity, Solid-solid phase transition enthalpy, Bis(n-octadecylammonium) tetrachloro-metallated(II)