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

作者：Li, Haibin; Wu, Shuixing; Liao, Yi; Su, Zhongmin^*; Kan, Yuhe; Tang, Xueling

来源：International Journal of Quantum Chemistry, 2012, 112(6): 1642-1653.

DOI：10.1002/qua.22984

• absorption
• DFT
• gold(III)
• complexes
• solvent effect
• spin orbit effect

The geometries of [Au(tpy)Cl]2+ (tpy = 2,2':6',2?-terpyridine) and its derivatives (14) 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 14. Then, their absorption spectra were investigated by scalar relativistic time dependent DFT (TDDFT)/SAOP/TZ2P in vacuum, in CH2Cl2, CH3CN 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 14 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 14 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.

• 出版日期2012-3-15
• 单位淮阴师范学院; 东北师范大学; 首都师范大学