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Density functional theory studies on structures and absorption spectra of [Au(tpy)Cl] 2+ and its derivatives: Role of basis set, functional, solvent effect, and spin orbit effect
Author(s) -
Li Haibin,
Wu Shuixing,
Liao Yi,
Su Zhongmin,
Kan Yuhe,
Tang Xueling
Publication year - 2011
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.22984
Subject(s) - density functional theory , time dependent density functional theory , chemistry , basis set , hybrid functional , absorption spectroscopy , solvent effects , configuration interaction , computational chemistry , polarizable continuum model , excited state , scalar (mathematics) , complete active space , spin–orbit interaction , atomic orbital , relativistic quantum chemistry , atomic physics , solvent , electron , physics , molecule , quantum mechanics , geometry , organic chemistry , mathematics
Abstract The geometries of [Au(tpy)Cl] 2+ (tpy = 2,2′:6′,2″‐terpyridine) and its derivatives ( 1 – 4 ) were optimized using relativistic density functional theory (DFT) at both scalar and two‐component spin orbit coupling (SOC) level of theory via zero order regular approximation (ZORA). The combination of OPTX exchange, PW91c correlation functional (denoted as OP91), all‐electron ZORA TZ2P basis set was found to be the optimal combination for geometry. The results reveal that both SOC and substituents have little effect on the geometry of complexes 1 – 4 . Then, their absorption spectra were investigated by scalar relativistic time dependent DFT (TDDFT)/SAOP/TZ2P in vacuum, in CH 2 Cl 2 , CH 3 CN solvents by means of conductor like screening model. The calculations indicate that the nature of the low‐lying spin‐allowed excited states is gold‐perturbed intraligand transition, namely charge reorganization. This fact also demonstrates that the influence of the polarity of solvent on absorption spectra of 1 – 4 is negligible. The spin orbit TDDFT was also performed to get further insight into the effect of SOC on the absorption spectra. It is found that the SOC has little influence on the simulation of electronic spectrum of complexes 1 – 4 due to no significant involvement of d‐orbitals during electronic transition. Our conclusions are reliable and are in good agreement with the previous experimental results and theoretical investigations. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012