Orbital and molecular design of new naphthyl-salen type transition metal complexes toward DSSC dyes

Dye sensitized solar cells (DSSC) emerged as a new class of low cost energy conversion devices. In this study, we investigated a class of transition metal complexes [ML(CH₃OH)]; M = Mn(l), Fe(2), Co(3), Ni(4), Cu(5) and Zn(6) and H₂L is naphthyl-salen Schiff base ligand. The COOH group of the complexes leads to better ability for adsorption of dyes. These complexes were characterized employing elemental analysis, powder X-ray analysis, IR, UV-Vis-NIR electronic spectroscopy and so on. Light absorption of the all the complexes shows that it-conjugated naphthyl ring makes these complexes efficient as dyes in DSSC. However, spatial distribution of excited orbitals associated with absorption properties (UV-Vis absorption spectra) calculated by TD- DFT method revealed one of the important factors about orbitals and molecular design of metal complexes for DSSC dyes.