Solid-to-solid polymorphic phase transitions in two isostructural Bi(III) complexes with 1-phenylethyl-N-ethylthiosemicarbazide and halogens

Two isostructural (in room temperature) complexes of Bi(III) with halogens and sulfur ligands have been investigated in terms of the solid-to-solid phase transitions indicated by temperature. Both chloride and bromide (X) complexes of the general formula (& mu;(2)-X)-(BiX2L2)(2) exhibit some phase transitions between 100 and 333 K, which, apart from the numerous similarities, show significant differences, which have been noted and analyzed in detail in this paper by using different techniques, i.e., powder and single crystal diffraction or DSC. The obtained results have also been collated with those obtained for solid solutions of both complexes.