Single-crystal-to-single-crystal structural transformations of two sandwich-like Cu(II) pyrazolate complexes and their excellent catalytic performances in MMA polymerization

Reactions of Cu(OAc)(2)center dot H2O with dmnpzH in EtOH produce a heptanuclear copper(II) pyrazolate complex [Cu-7(OH)(2)(OAc)(6)(dmnpz)(6)(EtOH)(6)], which is able to undergo a SCSC structural transformation from a lower symmetry structure to a higher symmetry structure via replacement of ligated-EtOH molecules with MeOH; both complexes along with the solvent-free species exhibit high catalytic activity in the polymerization of MMA.