Syntheses, crystal structures and fluorescent properties of R,R-DIOP based copper (I) and cadmium (II) complexes {R,R-DIOP = (4R,5R)-trans-4,5-bis(diphenylphosphinomethyl)-2,2-dimethyl-1,3-dioxalane}

Two chiral complexes, [CuCl(R,R-DIOP)]2 (1) and [CdCl2(R,R-DIOP)]n (2), have been synthesized by reaction of CuCl or CdCl2 with chiral diphosphine ligand R,R-DIOP under argon. They were characterized by elemental analysis, IR, UV–vis, fluorescence spectra and single-crystal X-ray diffraction. X-ray analysis indicates that the metal centers (CuI for 1 and CdII for 2) are both in distorted tetrahedral environment, but 1 is a binuclear complex in which CuI ions are surrounded by two μ2-bridging chloride ions and two bismonodentate coordinated R,R-DIOP ligands; while 2 is a helical polymer along b axis and each CdII ion is coordinated with two chloride ions and two P atoms of two μ2-bridging R,R-DIOP ligands. Both of them crystallize in monoclinic system, space group P 21, with a = 9.8855(7) Å, b = 37.857(3) Å, c = 23.9585(16) Å, β = 92.0920(10)°, Z = 6 for (1) and a = 10.1740(8) Å, b = 13.9899(11) Å, c = 11.4007(9) Å, β = 108.3690(10)°, Z = 2 for (2). Fluorescence measurements show that complex 1 can emits much strong blue emission than 2 at room temperature in the solid state.