title: Tuning photophysics and nonlinear absorption of bipyridyl platinum(II) bisstilbenylacetylide complexes by auxiliary substituents.
abstract: The photophysics of six bipyridyl platinum(II) bisstilbenylacetylide complexes with different auxiliary substituents are reported. These photophysical properties have been investigated in detail by UV-vis, photoluminescence (both at room temperature and at 77 K) and transient absorption (nanosecond and femtosecond) spectroscopies, as well as by linear response time-dependent density functional theory (TD-DFT) calculations. The photophysics of the complexes are found to be dominated by the singlet and triplet π,π* transitions localized at the stilbenylacetylide ligands with strong admixture of the metal-to-ligand (MLCT) and ligand-to-ligand (LLCT) charge-transfer characters. The interplay between the π,π* and MLCT/LLCT states depends on the electron-withdrawing or -donating properties of the substituents on the stilbenylacetylide ligands. All complexes exhibit remarkable reverse saturable absorption (RSA) at 532 nm for nanosecond laser pulses, with the complex that contains the NPh(2) substituent giving the strongest RSA and the complex with NO(2) substituent showing the weakest RSA.
authors.affiliation: Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108-6050, USA.
authors.forename: Zhongjing
authors.initials: Z
authors.lastname: Li
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Badaeva
authors.forename: Dapeng
authors.initials: D
authors.lastname: Zhou
authors.forename: Josiah
authors.initials: J
authors.lastname: Bjorgaard
authors.forename: Ksenija D
authors.initials: KD
authors.lastname: Glusac
authors.forename: Svetlana
authors.initials: S
authors.lastname: Killina
authors.forename: Wenfang
authors.initials: W
authors.lastname: Sun
mesh_terms: D008024:Ligands; D015394:Molecular Structure; D009944:Organoplatinum Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D055668:Photochemical Processes; D011789:Quantum Theory
chemical_list: D008024:Ligands; D009944:Organoplatinum Compounds; C574952:bipyridyl platinum(II)bisstilbenylacetylide