title: The electronic structures and photophysical properties of platinum complexes with C^N^N ligands: the influence of the carborane substituent.
abstract: Carboranes have attracted increasing interest in the scientific community due to their remarkable structures and strong electron-withdrawing abilities. In this article, four platinum complexes [(C^N^N)PtC[triple bond, length as m-dash]CPh](1), [(C^N^N)PtC[triple bond, length as m-dash]C-TPA](2), [(C^N^N)PtC[triple bond, length as m-dash]C-TAB](3), [(C^N^N)PtC[triple bond, length as m-dash]C-CB](4) (where TPA = triphenylamine, TAB = triarylboryl, CB = o-carborane) have been calculated via density functional theory (DFT) and time-dependent density functional theory (TDDFT) methods to mainly explore the influence of carborane substituents on electronic structures, photophysical properties and radiative decay processes. The calculated results reveal that 2 with electron-donating triphenylamine has a low radiative decay rate constant and a red-shifted emission band, but 3 and 4 containing electron-withdrawing triarylboryl and o-carborane exhibit the opposite properties, especially 4 is supposed to have the highest phosphorescence quantum yield with the smallest nonradiative decay rate constant. These findings successfully illustrated the structure-property relationship and the designed complex 4 with carborane can serve as a highly efficient phosphorescent material in the future.
authors.affiliation: College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P.R. China. shenw@swu.edu.cn.
authors.forename: Wenting
authors.initials: W
authors.lastname: Zhang
authors.forename: Yafei
authors.initials: Y
authors.lastname: Luo
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Xu
authors.forename: Li
authors.initials: L
authors.lastname: Tian
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.forename: Rongxing
authors.initials: R
authors.lastname: He
authors.forename: Wei
authors.initials: W
authors.lastname: Shen