Synthesis, spectral, electrochemical, crystal structure studies of two novel di-μ-halo-bis[halo(2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline)cadmium(II)] dimer complexes and their thermolysis to nanometal oxides

•Two neutral dimer Cadmium(II) complexes of general formula [Cd2(dmdphphen)2X4] were synthesized.•The desired complexes were fully characterized.•Complex 1 was characterized by X-ray single crystal.

Two new neutral dimer Cadmium(II) complexes, [Cd2(dmdphphen)2X4] and where X = Cl (complex 1), Br (complex 2), and dmdphphen = 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, were synthesized and characterized by an elemental analysis, UV–Vis, IR, TG/DTA, CV and single crystal X-ray diffraction. Complex 1 crystallizes in the triclinic system with the space group P-1 with unit cell parameters a = 10.1124(8) Å, b = 10.8875(8) Å, c = 11.5730(9) Å, α = 108.323(3)°, β = 107.010(3)°, γ = 91.260(3)° V = 1147.51(15) Å3 and Z = 1. The Cd(II) ions are located in a slightly distorted square-pyramidal geometry. The complexes exhibit a quasi-reversible one electron response at −570 mV vs. Cp2Fe/Cp2Fe+, which has been assigned Cd(II)/Cd(III) couples. TG/DTA result shows that these complexes are very stable and decomposed through one step reaction. Calcination of Complex 1, revealed the formation of Cubic nanoparticle CdO.