Electric conductances of tributylammonium (n-Bu(3)NH(+)) or diethylcyclohexylammonium (Et(2)N(C6H11H+) halides (chloride, bromide, and iodide) were measured in benzonitrile at 15, 25, 35, and 45 degrees C. Observed molar conductivities (Lambda/S cm(2) mol(-1)) for (0.4-6,0) x 10(-3) mol dm(-3) of the salts were analyzed by our method The ion pair and the "symmetrical" triple ion formation constants of the trialkylammonium chlorides (R(3)NHCl) decreased (instead of decreasing permittivity) with increasing temperature. Constant values of Walden products (Lambda(0) eta) of the ions over temperature changes suggested a constant solvation ability of the solvent within the temperature range. The temperature dependency of the formation constants for the bromides (R(3)NHBr) was smaller than that for the chlorides. The formation constants for the iodides (R(3)NHI) were almost independent of temperature. Thermodynamic parameters (Delta G(0), Delta H-0, and Delta S-0) for the ion pair and triple ion formation constants of the six salts were evaluated.