Concentration Gradient-Induced Syntheses and Crystal Structures of Two Copper(II) Coordination Polymer Based on Phthalic Acid and 2,2'-Bipyridine.

The reaction of copper nitrate, phthalic acid (1,2-HBDC), and bipyridine in ammonia/ethanol media affords two multi-copper (II) cluster-based coordination polymers, namely {[Cu(bpy)(OH)(BDC)]·2OH·13HO} () and {[Cu(BDC)(bpy)(HO)]·3HO} (), under ambient conditions, with forming at the bottom and at the upper edge of the same beaker. The single-crystal structures reveal that it is a rare case of gradient-induced formation of different multi-copper(II) cluster-based CPs within a single-solution chemical reaction. crystallizes in the monoclinic system, sp. gr. 2/c, and is composed of chair-like tetranuclear [Cu(-OH)(bpy)(BDC)] clusters as secondary building units, bridged by BDC ligands to form a two-dimensional layer framework, while crystallizes in the monoclinic system, sp. gr. 2/n, with binuclear [Cu(1,2-BDC)(bpy)(HO)] clusters linked by bridging BDC ligands to form a one-dimensional looped double chain. Through intermolecular - stacking and hydrogen bonds between the coordination water, lattice water, and free oxygen atoms from carboxylate, both compounds yield a 3D supramolecular structure.