title: Near-IR Broadband-Absorbing trans-Bisphosphine Pt(II) Bisacetylide Complexes: Preparation and Study of the Photophysics.
abstract: Broadband near-IR absorbing trans-bis(trialkylphosphine) Pt(II) bisacetylide binuclear complex (Pt-1) was prepared with boron-dipyrromethene (Bodipy) and styrylBodipy acetylide ligands. Pt-1 shows strong absorption bands at 731 and 503 nm. Singlet energy transfer (EnT) and efficient intersystem crossing of the central coordinated Bodipy ligand were proposed to be responsible for the efficient funneling of the excitation energy to the triplet-state manifold. Reference complexes containing only a single Bodipy ligand were prepared for comparison (with styrylBodipy ligand Pt-0 or Bodipy ligand Pt-2). The molecular structures were confirmed by single-crystal X-ray diffraction. The photophysical properties were studied with steady-state and time-resolved transient absorption spectroscopies, electrochemical characterization, and density functional theory/time-dependent density functional theory calculations. Dual fluorescence was observed for Pt-1. Singlet EnT in Pt-1 was proposed based on the fluorescence quenching/excitation spectra, and femtosecond transient absorption spectra (energy transfer rate constant kEnT = 2.2 × 10(10) s(-1)). With nanosecond transient absorption spectra, intramolecular triplet-state energy transfer in Pt-1 was proved. Gibbs free energy changes of charge separation indicate that the photoinduced intramolecular electron transfer in Pt-1 is thermodynamically prohibited. Intermolecular triplet transfer between Pt-2 and L-1 was studied with nanosecond transient absorption spectra; the EnT rate and energy transfer efficiency were determined as 3.6 × 10(4) s(-1) and 94.5%, respectively. The singlet oxygen ((1)O2) photosensitizing of Pt-1 was improved as compared to the complexes containing only a single visible-light-absorbing chromophore.
authors.affiliation: †State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, E-208 West Campus, 2 Ling Gong Rd., Dalian 116024, P. R. China.
authors.forename: Wenbo
authors.initials: W
authors.lastname: Yang
authors.forename: Ahmet
authors.initials: A
authors.lastname: Karatay
authors.affiliation: †State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, E-208 West Campus, 2 Ling Gong Rd., Dalian 116024, P. R. China.
authors.forename: Jianzhang
authors.initials: J
authors.lastname: Zhao
authors.affiliation: §College of Chemistry and Chemical Engineering, Liaoning Normal University, Dalian 116029, P. R. China.
authors.forename: Jian
authors.initials: J
authors.lastname: Song
authors.affiliation: †State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, E-208 West Campus, 2 Ling Gong Rd., Dalian 116024, P. R. China.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhao
authors.affiliation: §College of Chemistry and Chemical Engineering, Liaoning Normal University, Dalian 116029, P. R. China.
authors.forename: Yongheng
authors.initials: Y
authors.lastname: Xing
authors.affiliation: †State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, E-208 West Campus, 2 Ling Gong Rd., Dalian 116024, P. R. China.
authors.forename: Caishun
authors.initials: C
authors.lastname: Zhang
authors.affiliation: †State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, E-208 West Campus, 2 Ling Gong Rd., Dalian 116024, P. R. China.
authors.forename: Cheng
authors.initials: C
authors.lastname: He
authors.forename: Halime Gul
authors.initials: HG
authors.lastname: Yaglioglu
authors.forename: Mustafa
authors.initials: M
authors.lastname: Hayvali
authors.forename: Ayhan
authors.initials: A
authors.lastname: Elmali
authors.forename: Betül
authors.initials: B
authors.lastname: Küçüköz