AlAbbad Sanaa, Sardot Tova, Lekashvili Oliko, Decato Daniel, Lelj Francesco, Alexander Ross J B, Rosenberg Edward
Department of Chemistry and Biochemistry, University of Montana, Missoula MT, 59812 U.S.A.
Department of Chemistry, Ivane Javakhishvili Tbilisi State University, 1, I. Chavchavadze ave., 0128 Tbilisi, Georgia.
J Mol Struct. 2019 Nov 5;1195:620-631. doi: 10.1016/j.molstruc.2019.06.005. Epub 2019 Jun 10.
The ground (S) and excited triplet (T) electronic states and corresponding optical spectra of a series of cationic complexes [RuH(CO)L(PPh)] (L=2,2´-bipyridyl) (Rubpy), 4,4´-dicarboxylic-2,2´-bipyridyl (Rudcbpy), bis-4,4'-(N-methylamide)-2,2´-bipyridyl (Rudamidebpy), bis-4,4'-(methyl)-2,2´-bipyridyl (RudMebpy), [Ru(CO)dcbpy(PPh)] (Ru(2CO)dcbpy), and [Ru(H)dcbpy(PPh)] (Ru(2H)dcbpy) have been studied by combined Density Functional/Time-Dependent Density Functional (DFT/TDDFT) techniques using different combinations of DFT exchange-correlation functionals and basis sets. PBE0/LANL2DZ provided more accurate geometries to describe S whereas B3LYP/LANL2DZ predicted spectral energies that correlated better with the available experiment data. The Ru (II) complexes with different substituents emit photons ranging from 560-610 nm in the series RudMebpy, Rubpy, Rudamidebpy, Rudcbpy. The calculations predicted a maximum emission at about 540 nm for the complex constructed from two carbonyl π-acceptors ligands to the dcbpy, while an emission in the far infrared region is calculated when two H σ-donor ligands to the dcbpy. Our calculation results show correlations between HOMO-LUMO energy gap, Stokes shift, and T distortion, which reflect the different effects of electron-withdrawing and donating groups. We proposed that these correlations can be used to predict the photophysical properties for new complexes.
采用不同的密度泛函理论（DFT）交换相关泛函和基组组合，通过密度泛函/含时密度泛函理论（DFT/TDDFT）相结合的技术，研究了一系列阳离子配合物[RuH(CO)L(PPh)]（L = 2,2'-联吡啶）（Rubpy）、4,4'-二羧酸-2,2'-联吡啶（Rudcbpy）、双-4,4'-(N-甲基酰胺)-2,2'-联吡啶（Rudamidebpy）、双-4,4'-(甲基)-2,2'-联吡啶（RudMebpy）、[Ru(CO)dcbpy(PPh)]（Ru(2CO)dcbpy）和[Ru(H)dcbpy(PPh)]（Ru(2H)dcbpy）的基态（S）和激发三重态（T）电子态以及相应的光谱。PBE0/LANL2DZ能提供更精确的几何结构来描述基态S，而B3LYP/LANL2DZ预测的光谱能量与现有实验数据的相关性更好。在RudMebpy、Rubpy、Rudamidebpy、Rudcbpy系列中，具有不同取代基的Ru（II）配合物发射的光子波长范围为560 - 610 nm。计算预测，由两个羰基π受体配体与dcbpy构建的配合物的最大发射波长约为540 nm，而当两个H σ供体配体与dcbpy结合时，计算得到的发射在远红外区域。我们的计算结果表明了最高占据分子轨道（HOMO）-最低未占据分子轨道（LUMO）能隙、斯托克斯位移和T畸变之间的相关性，这反映了吸电子和供电子基团的不同影响。我们提出这些相关性可用于预测新配合物的光物理性质。
