CdL(3)(ClO4)(2), ZnL(2)X(2), CdL(2)X’(2) . nH(2)O (where L is N-1-isopropyl-2-methyl-1,2-propanediamine, X is Cl, Br, I, ClO4, SCN, 0.5SO(4) and 0.5SeO(4); n = 0 when X’ is Cl, Br, I, SCN and 0.5SO(4); n = 3 when X’ is ClO4; n = 4 when X’ is 0.5SeO(4)) and MLX(2) (M is Zn(II) or Cd(II) and X is Cl, Br and I) were synthesized from solution. The species CdL(2)(ClO4)(2) and MLX(2) (M is Zn(II) or Cd(II) and X is Cl, Br and I) were synthesized from the corresponding parent complexes by the temperature-arrest technique. CdL(2)(SCN)(2) exists in two isomeric forms and bath have been synthesized. One of the isomers undergoes an irreversible phase transition (102-120 degrees C, Delta H = 12.8 kJ mol(-1)) and transforms to the other form in the solid phase. ZnL(2)(ClO4)(2) shows a reversible phase transition (178-208 degrees C, Delta H = 9.2 kJ mol(-1)) upon heating in the solid phase. CdL(2)(ClO4)(2) undergoes a reversible phase transition (73-98 degrees C, Delta H = 4.4 kJ mol(-1)) and then on further heating shows time-dependent reversible phase transitions (136-190 degrees C, Delta H = 15.3 kJ mol(-1)) in the solid phase. The phase transition in CdL(2)(SCN)(2) is due to the change in coordination mode of the thiocyanate ion, whereas in CdL(2)(ClO4)(2), the time-dependent reversible phase transition is due to conformational changes in the diamine chelate rings.