Abstract:Dilithium 5, 5′-bistetrazole-1, 1′-diolate(Li2DHBT), disodium 5, 5′-bistetrazole-1, 1′-diolate(Na2DHBT) and dipotassium 5, 5′-bistetrazole-1, 1′-diolate(K2DHBT)were synthesized from 5, 5′-bistetrazole-1, 1′-diole with high yields over 90%, while dihydroxylammonium 5, 5′-bistetrazole-1, 1′-diolate(HATO) was synthesized by ion exchange reaction with lithium ions with high yield of 94.1%.Using the laser monitoring technique, the solubilities of HATO、Li2DHBT、Na2DHBT and K2DHBT in water from 20 ℃ to 60 ℃ were measured by dynamic method.The experimental data were correlated with the ideal solution model and Apelblat equation.Results show that the solubilities of four kinds of salts increase with increasing temperature.The average relative deviations between experimental and calculated data by ideal solution model and Apelblat equation are less than 3.5%, while the Apelblat equation gives the better fit with the experimental data.The enthalpies of dissolution of HATO, Li2DHBT, Na2DHBT, K2DHBT are 27.991, 27.632, 31.125 kJ·mol-1 and 17.991 kJ·mol-1, and the entropy of dissolution of HATO, Li2DHBT, Na2DHBT, K2DHBT are 23.431, 36.807, 41.251 J·mol-1·K-1 and 3.139 J·mol-1·K-1, respectively.