CONDENSED MATTER DFT STUDY OF THE OPTICAL AND VIBRATION SPECTRA OF A SERIES OF PLATINUM-OLEFIN COMPLEXES * C.I. OPREA 1 , F. MOSCALU 1 , A. DUMBRAVA 2 , S. IOANNOU 3 , A. NICOLAIDES 3 , M.A. GÎRğU 1 * 1 Department of Physics, Ovidius University of ConstanĠa, Bd. Mamaia 124, ConstanĠa 900527, Romania, *E-mail: girtu@univ-ovidius.ro 2 Department of Chemistry, Ovidius University of ConstanĠa, Bd. Mamaia 124, ConstanĠa 900527, Romania 3 Department of Chemistry, University of Cyprus, Nicosia 1678, Cyprus Received October 28, 2009 We report Density Functional Theory calculations providing the vibrational and optical properties of the homologous series of Pt-pyramidalized olefin complexes (CH 2 ) n -(C 8 H 10 )Pt(PX 3 ) 2 , where X ţ H and Ph, and n ţ 0, 1, 2, and 3. With an emphasis on n ţ 1, we compare and contrast the complexes revealing the role of the additional phenyl groups on the infrared and optical spectra. The relevance of these Pt-based compounds for dye-sensitized solar cells is discussed. Key words: Density functional theory, infrared and optical spectra, olefin, dye-sensitized solar cells. 1. INTRODUCTION In the field of asymmetric catalysis of great importance are platinum-olefin complexes, which have a rich history as ligands in organometallic chemistry [1]. The lability of olefin ligands ensures rapid and quantitative exchange reactions, which allows in situ preparation of optically active catalyst systems. Several such Pt-olefin complexes were found to display a pyramidalized structure [2]. Pyramidalized alkenes are molecules containing carbon–carbon double bonds in which one or both of the sp 2 carbon atoms do(es) not lie in the same plane as the attached atoms [2, 3]. Alkenes of this kind are also interesting due to their intriguing physical properties and their fascinating reactivity [4]. * Paper presented at the 10 th International Balkan Workshop on Applied Physics, July 6–8, 2009, ConstanĠa, Romania. Rom. Journ. Phys., Vol. 56, Nos. 1–2, P. 125–133, Bucharest, 2011