Photochemistry of the orthometalated cis-bis(2-(2-thienyl)pyridine)platinum(II) complex in halocarbon solvents

Journal Article · Wed Dec 09 04:00:00 EST 1987 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00259a021· OSTI ID:6974403

Sandrini, D; Maestri, M; Balzani, V; Chassot, L; von Zelewsky, A

The photochemical and luminescence behavior of the orthometalated Pt(thpy)/sub 2/ complex, where thpy/sup -/ is the ortho-C-deprotonated form of 2-(2-thienyl)pyridine, has been studied under a variety of experimental conditions, and the mechanisms of the excited-state reactions and of the subsequent thermal processes are discussed. In degassed CH/sub 3/CN the complex is not photosensitive and exhibits luminescence from the lowest triplet metal-to-ligand charge-transfer (/sup 3/MLCT) excited state with phi/sub em/ = 0.26 and tau = 2.4 ..mu..s. In CH/sub 2/Cl/sub 2/, CHCl/sub 3/, or CH/sub 3/CN/CH/sub 2/Cl/sub 2/ solvents, the complex maintains its luminescent properties and undergoes a photooxidative addition reaction with formation of Pt(thpy)/sub 2/(Cl)(R) (R = CH/sub 2/Cl or CHCl/sub 2/) as the sole observed product. In the mixed solvent, the quantum yield of the photoreaction increases with increasing CH/sub 2/Cl/sub 2/ concentration. In neat CH/sub 2/Cl/sub 2/, the quantum yield of the photoreaction is 0.30 and 0.10 for 313- and 430-nm excitation, respectively. In CH/sub 2/Cl/sub 2/, complete quenching of the luminescent /sup 3/MLCT excited state by anthracene via an energy-transfer mechanism is accompanied by only partial quenching of the photoreaction. By contrast, oxygen is a better quencher for the photoreaction than for the luminescence emission. In both cases the fraction of quenched reaction depends on the excitation wavelength.

• Research Organization: G. Ciamician dell'Universita, Bologna (Italy)
• OSTI ID: 6974403
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 109:25; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
AZINES
CATALYSTS
CHEMICAL REACTIONS
CHEMISTRY
COMPLEXES
DATA
EFFICIENCY
ENERGY LEVELS
EXCITED STATES
EXPERIMENTAL DATA
HETEROCYCLIC COMPOUNDS
INFORMATION
LUMINESCENCE
NUMERICAL DATA
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SOLVENTS
OXIDATION
PHOTOCHEMISTRY
PLATINUM COMPLEXES
PYRIDINES
QUANTUM EFFICIENCY
SOLVENT PROPERTIES
SOLVENTS
TRANSITION ELEMENT COMPLEXES