Effect of reaction conditions on the assembly, structures and fluorescent sensing behaviors of Cd(II) metal-organic complexes

Three Cd(II) metal-organic complexes, namely [Cd(phen) 2 Cl 2 ]( 1 ), [Cd(phen)Cl 2 ]( 2 ) and [Cd(phen)(cam)]· H 2 O( 3 )(phen=1,10-phenanthroline, H 2 cam=camphoric acid), were hydrothermally synthesized using Cd 2+ , phen and H 2 cam as raw materials under different conditions of pH values, reaction temperatures or reactant ratios. The prepared complexes were structurally characterized by means of single-crystal X-ray diffraction, and the results show that complex 1 is a 2D supramolecular complex, which consists of [Cd(phen) 2 Cl 2 ] mononuclear subunits, while complex 2 shows a 1D chain structure, in which Cd(II) ions are connected by chloride(Cl – ) bridges, with phen hanging on both sides of the chain. No cam anions have been observed in the structures of complexes 1 and 2 . In complex 3 , cam connects Cd(II) ions to construct a 2D network, in which phen acts as terminal ligands. The adjacent 1D chains for complex 2 and the adjacent 2D layers for complex 3 are further linked by hydrogen bonding interactions or π-π intermolecular interactions to form 3D supramolecular networks, respectively. The effects of reaction conditions on the assembly and structures of the complexes have been discussed. The fluorescent and photocatalytic properties of complexes 1 ― 3 and the fluorescent sensing behaviors of complexes 2 and 3 have also been investigated.