The results reported in this work demonstrate the effect of chemical composition and structure type on the melting temperature of ABX3 hybrid organic-inorganic materials. Specifically, the comparison of four novel [TAlA][M(dca)3] structures with 5 known materials facilitated a study of the relationship of thermal properties to chemical structure. The size of A-site alkylammonium cation and Bsite transition metal was altered and found to influence Tm. In particular, increasing the size of the A-site cation from TPrA→TBuA→TPnA was observed to result in an increase in Tolerance Factor, and decrease in melting temperature through an increase in the entropy of fusion.