title: Optical Excitation in Donor-Pt-Acceptor Complexes: Role of the Structure.
abstract: The optical properties of the Pt complexes in the form of donor-metal-acceptor (D-M-A) were studied at the first-principles level. Calculated results show that for the frontier molecular orbitals (MOs) of a D-M-A structure the energies of unoccupied frontier MO can be mainly determined by the interaction between M and A, whereas the M-A and M-D interactions both determine the energies of occupied frontier MO. By developing a straightforward transition dipole decomposition method, we found that not only the local excitations in D but also those in A can significantly contribute to the charge-transfer (CT) excitation. Furthermore, the calculations also demonstrate that by tuning the dihedral angle between D and A the transition probability can be precisely controlled so as to broaden the spectrum region of photoabsorption. For the D-M-A molecule with a delocalized π system in A, the CT excitation barely affects the electronic structures of metal, suggesting that the oxidation state of the metal can be kept during the excitation. These understandings for the optical properties of the D-M-A molecule would be useful for the design of dye-sensitized solar cells, photocatalysis, and luminescence systems.
authors.affiliation: Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China , Hefei 230026, Anhui, P. R. China.|Department of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology , S-106 91 Stockholm, Sweden.
authors.forename: Zu-Yong
authors.initials: ZY
authors.lastname: Gong
authors.affiliation: Department of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology , S-106 91 Stockholm, Sweden.
authors.forename: Sai
authors.initials: S
authors.lastname: Duan
authors.affiliation: Department of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology , S-106 91 Stockholm, Sweden.|College of Science, Yanshan University , Qinhuangdao 066004, China.
authors.forename: Guangjun
authors.initials: G
authors.lastname: Tian
authors.affiliation: Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China , Hefei 230026, Anhui, P. R. China.
authors.forename: Guozhen
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China , Hefei 230026, Anhui, P. R. China.
authors.forename: Jun
authors.initials: J
authors.lastname: Jiang
authors.affiliation: Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China , Hefei 230026, Anhui, P. R. China.|Department of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology , S-106 91 Stockholm, Sweden.
authors.forename: Yi
authors.initials: Y
authors.lastname: Luo