Premium
Computational studies on the spectroscopic properties of the 2‐pyridylpyrazolate‐based platinum(II) complexes with modified pyrazolate fragment
Author(s) -
Bai FuQuan,
Zhou Xin,
Liu Tao,
Zhao GuangJin,
Zhang JianPo,
Zhang HongXing
Publication year - 2008
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.21791
Subject(s) - platinum , chemistry , excited state , phosphorescence , atomic orbital , density functional theory , homo/lumo , time dependent density functional theory , photochemistry , ligand (biochemistry) , computational chemistry , crystallography , molecule , atomic physics , electron , catalysis , fluorescence , physics , organic chemistry , biochemistry , receptor , quantum mechanics
Electronic structures and spectroscopic properties of a series of platinum(II) complexes based on the 2‐pyridylpyrazolate ligand with modified pyrazolate fragment have been studied by the time‐dependent density functional theory (TD‐DFT) calculations. The ground‐ and excited‐state structures were optimized by the DFT and single‐excitation configuration interaction (CIS) methods, respectively. The calculated structures and spectroscopic properties are in agreement with the corresponding experimental results. The results of the spectroscopic investigations revealed that the lowest‐energy absorptions have 1,3 MLCT/ 1,3 ILCT mixing characters. When the electron‐withdrawing groups (CF 3 , C 3 F 7 ) are introduced into the pyrazolate fragment, the lowest‐energy absorptions are blue‐shifted compared with that without substituents on the pyrazolate fragment, while the opposite case is observed for the electron‐donating groups (Me, t Bu, etc.). Otherwise, the phosphorescent emissions of these complexes have the 3 MLCT/ 3 ILCT character and should be originated from the lowest‐energy absorptions. When the pyrazolate fragment is replaced by the indazole group, the HOMO and LUMO orbitals of the pyridyl‐indazolate ligand platinum(II) complexes have obvious π and π* orbital characters. Therefore, there is no evident MLCT character in the lowest energy absorption and emission. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009