取代基效应对锇(Ⅱ)羟基喹啉配合物结构和光谱性质的影响

从理论上研究了一系列Os(CO)3(tfa)(O^N)](tfa=三氟乙酸;O^N=5-氟-羟基喹啉(1),羟基喹啉(2)和2:甲基-羟基喹啉(3))配合物的结构和光谱特征.分别采用B3LYP/LANL2DZ和CIS/LANL2DZ方法优化了它们的基态和激发态结构.计算得到的Os-C、Os-N和Os-O基态键长和相应...

The effect of substituent on the electron structures and spectroscopic properties of quinolinolate Os (Ⅱ) complexes

The series of Os（Ⅱ） complexes Os（CO）3（tfa）（O^N）]（tfa=trifluoroacetate;O^N=5-fluoro-quinolinolate（1）,quinolinolate（2）,and 2-methyl-quinolinolate（3）） have been investigated theoretically to explore their electronic structures and spectroscopic properties.Their structures in the ground and excited states have been optimized at the B3LYP/LANL2DZ and CIS/LANL2DZ levels,respectively.The calculated bond lengths of Os-C,Os-N,and Os-O in the ground state agree well with the corresponding experimental results.Upon excitation,the bond lengths of Os-C lengthen by 0.04 to 0.06 and that of Os-O and Os-N shorten by 0.004 to 0.02 compared with those ground states.At the TD-DFT and PCM levels,1-3 lowest-lying absorptions occurs at 444（1）,431（2）,and 446（3） nm and phosphorescent emissions occurs at 679（1）,638（2）,and 646（3） nm,respectively.The highest occupied molecular orbitals（HOMO） and the lowest unoccupied molecular orbitals（LUMO） of three complexes are mainly manifested as π and π＊ orbital characters of O^N ligand,therefore,the lowest-lying absorptions and emissions were assigned to the π-π＊ transition mixed with some LLCT and MLCT characters.It is shown that the absorptions and emissions are significantly dominated by the O^N ligand.