Copper(II) Acetate/Bis(4-pyridylthio)methane System: Synthesis, Structural Diversity, and Single-Crystal to Single-Crystal Transformation

Four new coordination compounds have been obtained by the reaction of copper(II) acetate with SCS [bis(4-pyridylthio)methane], namely, [Cu-2(AcO)(4)(SCS)] (1), [Cu-2(AcO)(4)(SCS)]center dot solv (2), [Cu-4(AcO)(8)(SCS)(5)(H2O)(6)]center dot 4H(2)O (3), and [Cu-4(OH)(2)(AcO)(6)(SCS)(2)]center dot 10H(2)O (4). Structural diversity is achieved by the copper acetate moiety in combination with the flexibility of the SCS ligand. X-ray structural analysis revealed that the compounds have different structural motifs: linear chains in 1, zigzag chains in 2, undulated tetramers in 3, and ladder-like chains in 4. The structures are further connected through hydrogen-bonding interactions with trapped solvent molecules in the crystal lattices (2-4). Guest molecules have a decisive influence on the final crystal system for 2-4. Compound 2 exhibits a temperature-induced single-crystal to single-crystal (SC-SC) transformation, and phase transitions from 2 and 3 to 1 have been found in an irreversible desolvation or recrystallization process.