Classification of Raman active modes of platinum(II) acetylides: A combined experimental and theoretical study

Non-resonance Raman scattering of platinum(II) acetylide molecules is studied both by theory and experiment. Differential cross sections are presented for bis((4-(phenyl-ethynyl)phenyl)ethynyl)bis(tri-n-butylphosphine)platinum(II) (Pt1), and for bis((4-(phenyl-ethynyl)bis(tri-n-butylphosphine)platinum(II) substituted with triazole end group (Z1). All intense bands in the observed Raman scattering are assigned to symmetric vibrations of Pt-C{triple bond, long}C, C{triple bond, long}C, and phenyl groups; a reliable interpretation includes some details of relative intensities for the stretching and in-plane bending modes. The Raman spectra verify that the Pt-acetylide dyes remain intact during the material processing, indicating that they retain functionality for applications like in optical power limiting, nonlinear optics, and light emitting diodes.