Optical and infrared properties of a series of pyramidalized olefin Pt-complexes - DFT study

We report Density Functional Theory (DFT) calculations providing the geometrical and electronic structures, as well as the vibrational and optical properties of the homologous series of Pt-pyramidalized olefin complexes (CH2)(n)-(C8H10)Pt(PX3)(2), where X = H and Ph, and n = 0, 1, 2, and 3. All complexes were geometry optimized for the singlet ground state in vacuum using DFT methods with B3LYP exchange-correlation functional and the Effective Core Potential LANL2DZ basis set, within the frame of Gaussian03 quantum chemistry package. Electronic transitions were calculated at the same level of theory by means of Time Dependant-DFT. For both X = H and X = Ph complexes and regardless of n, the electronic absorption bands are located in the UV region of the spectrum, most transitions being assigned to metal to ligand charge transfers. We compare and contrast the complexes revealing the role of the number of CH2 groups, n, on the geometry, and infrared and optical spectra. The relevance of these Pt-based compounds as possible pigments for dye-sensitized solar cells is discussed.