Abstract
A new series of Zn(II) supramolecular isomers containing ditopic 1,3-di(pyridin-4-yl)urea (4bpu) ligand were synthesized and characterized by infrared analysis, elemental analysis and TGA as well as single-crystal X-ray diffraction analysis. Four solvent-induced pseudopolymorphic zinc (II) coordination polymers (CPs), namely, {[Zn(4bpu)(OAc)(2)](CH(3)OH)}(n) (1), {[Zn(4bpu)(OAc)(2)](C(2)H(5)OH)}(n) (2), {[Zn(4bpu)(OAc)(2)](HOCH(2)CH(2)OH)}(n) (3), and {[Zn(4bpu)(OAc)(2)](0.5H(2)O)}(n) (4), were prepared by the reaction of Zn(OAc)(2).2H(2)O and 4bpu via self-assembly under varying solvent systems. Also, a pair of polymorphic coordination polymers namely, {[Zn(4bpu)(OAc)(2)](CH(3)OH)}(n) (1α) and {[Zn(3)(4bpu)(3)(OAc)(6)](CH(3)OH)(2)}(n)(1β), was prepared in the presence of different organic additives. Single-crystal X-ray diffraction confirmed that 1-4 and 1α display 1D polymeric zig-zag chains and 1β exhibits 1D triple-stranded ladders that were self-assembled through various supramolecular interactions. In addition, a series of dissolution-recrystallization structural transformations (DRST) were performed on these supramolecular isomers.