Controlled Reversible Crystal Transformation of Cu(I) Supramolecular Isomers

Four copper(I) coordination polymers (CPs), {[CuIL]center dot CH3CN]}(n) (1), {[CuIL]center dot CHCl3}(n) (2), {[CuIL]center dot CH2Cl2}(n) (3), and [CuIL](n) (4), were prepared by self-assembly reactions between CuI and (2-pyrazinylcarbonyl)thiomorpholine (L). CPs 1-4 are interconnected by rhomboid Cu-I-2-Cu units. CPs 1 and 4 have one-dimensional loop-chain structures, and 2 and 3 adopt two-dimensional network structures. CPs 1-4 are pseudopolymorphic supramolecular isomers. CPs 2' and 3' are prepared by removal of solvate molecules from CPs 2 and 3, which are polymorphic supramolecular isomers with CP 4. Reversible crystal-to-crystal transformations were observed under appropriate conditions such as solvent or heat.