Dinuclear cadmium(II) complexes with distorted octahedral/monocapped trigonal prism coordination geometries: synthesis, crystal structure, DFT/TD-DFT calculation and photocatalytic degradation of methylene blue

Two dinuclear cadmium(II) complexes [Cd2(L1)2(dca)(NO3)] (1) and [Cd2(L2)2(SCN)(NO3)] (2) (HL1; 2-methoxy-6-[(2-phenylamino-ethylimino)-methyl]-phenol; and HL2; 2-[(2-ethylamino-ethylimino)-methyl]-6-methoxy-phenol) have been synthesized and characterized by X-ray crystal structure determination, FTIR, and mass spectroscopic studies. In complex 1, two metal centers have different coordination geometries, one is a distorted octahedral and another is a distorted monocapped trigonal prism. Whereas in complex 2, both metal centers possess distorted octahedral geometries. Experimental data of UV-vis electronic absorption spectral data have been compared with the calculated data obtained by DFT and TD-DFT calculation using B3LYP functional. The photocatalytic activities of the complexes have been studied using UV absorption spectroscopic technique and the results show that in presence of UV light both complexes 1 and 2 are active for photocatalytic decomposition of methylene blue (MB) by 54.0% and 50.3%, respectively. [Display omitted] Two Cd(II) complexes [Cd2(L1)2(dca)(NO3)] (1) and [Cd2(L2)2(SCN)(NO3)] (2) (HL1 = 2-methoxy-6-[(2-phenylamino-ethylimino)-methyl]-phenol; and HL2 = 2-[(2-ethylamino-ethylimino)-methyl]-6-methoxy-phenol), have been synthesized and characterized by single crystal structure analysis, IR and mass spectroscopic studies. Both the complexes 1 and 2 possess a triclinic crystal system with space group P1¯. In complex 1, geometry around one metal centre is distorted octahedral and other centre is distorted monocapped trigonal prism, whereas in complex 2, both the metal centres possess distorted octahedral geometries. Strong NH⋅⋅⋅O and weak aromatic CH⋅⋅∙O hydrogen bonding interactions in 1 and strong NH⋅⋅⋅O and NH⋅⋅⋅S hydrogen bonding in 2 results 1D and 2D supramolecular structures, respectively. Experimentally determined electronic spectral data have been compared with the calculated data obtained by DFT and TD-DFT calculation. Photocatalytic abilities of 1 and 2 have been examined by using spectroscopic technique and found that in presence of UV light both the complexes catalytically decomposed methylene blue by 54.0 % and 50.3 %, respectively.