Abstracts 2007

Abstract of Publication No. 579

Dominik Schaniel, Theo Woike, Bernard Delley, Daniel Biner, Karl W. Krämer and Hans-Ueli Güdel
Generation of one light-induced metastable nitrosyl linkage isomer in [Pt(NH3)4Cl(NO)]Cl2 in the red spectral range
Phys. Chem. Chem. Phys. 9, 5149-5157 (2007)      Full Text (PDF)      DOI-Link      Supplementary Data (PDF)     

Abstract: One metastable linkage nitrosyl isomer can be generated in [Pt(NH3)4Cl(NO)]Cl2 by irradiation with light in the red spectral range. The potential energy barrier for the thermal relaxation of the metastable state to the ground state has an amount of EA = (0.27 0.03) eV. The decay follows the Arrhenius law and EA is independent of temperature. At room temperature the metastable state has a lifetime of t = 3.8 105 s after generation by pulsed laser illumination. Below T = 100 K about 30% linkage NO isomers can be generated in a powder sample by irradiation with l = 658 nm. DFT calculations demonstrate the rotation of the NO ligand from PtNO to PtON as a unique linkage isomer. Consequently, only one new n(NO) stretching vibration is detected with a shift from 1673 cm1 to 1793 cm1 by 120 cm1, to higher frequencies in good agreement with the DFT calculations. In the metastable state new electronic absorption bands are observed in the blue-green and near infrared spectral range. The metastable state can be optically accessed via a (5d + p(NO)) p*(NO) transition. [Pt(NH3)4Cl(NO)]Cl2 is diamagnetic with a Pt(5d8) configuration and thus represents the first {MNO}8 complex with experimental evidence for a light-induced nitrosyl linkage isomer.

Last modified: 13.12.11 by Gabriela Frei