Studies on one 2D cadmium(II) coordination polymer and two mononuclear cadmium(II) complexes with trans or cis configuration having 3-bromo, 3,6-dibromo, and 3,8-dibromo 1,10-phenanthroline ligands

Abstract

Three novel Cd(II) complexes, formulated as [Cd(3,8-dibromo-1,10 -phen- κ 2N , N′)( l-tar)] n ( 1), trans-[Cd(3,8-dibromo-1,10 -phen- κ 2N , N′) 2(NO 3- κ 2O , O′) 2]·(CH 3CN) ( 2) and cis-[Cd(3,6-dibromo-1,10-phen- κ 2N , N′)(3-bromo-1,10-phen- κ 2N , N′)(NO 3- 2 O, O′)(CH 3OH- κO)](NO 3) ( 3) (phen = phenanthroline, l-tarH 2 = l-tartaric acid), have been synthesized and characterized in this paper. In coordination polymer 1, the [Cd 2(3,8-dibromo-phen) 2] 4+ cations are bridged by l-tar ligands into an infinite 2D lamellar polymer along the c-axis, and the neighboring 2D polymers are further extended into a 3D supramolecular network by π–π stacking interactions. Complexes 2 and 3 are both mononuclear cadmium complexes but with different conformation ( trans or cis). In the crystal packing structures of 2 and 3, molecules are arranged into three-dimensional (3D) frameworks by intermolecular hydrogen bonding and π–π stacking interactions.