新颖[Os(DMSO)_2(CN)_2(N^N)]配合物的结构和光谱特征  

The Structures and Spectroscopic Properties for a Series of Novel [Os( DMSO)_2( CN)_2( N^N) ]Complexes

作　　者：金丽[1] 张建坡[1] 李岩[1] 郝希云[1] 

机构地区：[1]吉林化工学院化学与制药工程学院,吉林吉林132022

出　　处：《吉林化工学院学报》2013年第11期29-33,共5页Journal of Jilin Institute of Chemical Technology

基　　金：吉林大学理论化学计算国家重点实验室开放课题基金资助(No.20130023)

摘　　要：采用密度泛函(B3LYP)和开壳层密度泛函(UB3LYP)方法分别优化了[(DMSO)2(CN)2Os(N^N)][N^N=bpy(1);N^N=phbpy(2);bpy=2,2'-吡啶;phbpy=4,4'-二苯基-2,2'-吡啶]配合物的基态和激发态结构.利用TD-DFT方法结合PCM溶剂化模型计算了它们在CH2Cl2溶液中的吸收和发射光谱.研究结果表明:优化得到的几何结构参数和相应的实验值符合得非常好,激发态几何相对基态变化较小,这与实验上观察到的较小的斯托克斯频移现象一致.两个配合物的最低能单态吸收分别在441(1)和453(2)nm,其磷光发射分别在631(1)和627(2)nm.1和2的高能占据分子轨道主要由金属和CN基配体占据,而低能非占据分子轨道主要受N^N配体成份控制,因此1和2的最低能吸收和发射被指认为MLCT跃迁,并混有少量的LLCT微扰.它们的高能吸收均表现为ππ*跃迁特征,但是它们属于两种不同类型的ππ*激发态.The ground and excited states structures of a series of novel Os （II） complexes [ （DMSO）2 （CN） 20s （N^N） ] [ N^N = bpy （ 1 ） ; N^N = phbpy （2） ;bpy = 2,2＇-bipyridine ;phbpy = 4,4＇-diphenyl-2, 2＇-bipyridine] were investigated theoretically by the Beckeg three parameter functional and the Lee-Yang-Parr （B3LYP） and unrestricted B3LYP methods, respectively. The TD-D^F method with the polarized continuum model （PCM） was employed to obtain their absorption and phosphorescent emission spectras in CH2C12 media. The results revealed that the optimized structural parameters agree well with the corresponding experimental results. There are little differences in structures between the ground and excited states, which is in agreement with the small Stokes-shift for observed in the experiments. The lowest-lying absorptions at 501 （1） and 510（2） nm and phosphorescent emissions at 631 （1） and 627 （2） nm for 1 and 2, respectively. As indicated in this paper,the high-energy occupied molecular orbitals were dominantly localized on the Os atom and CN ligand, while the lowest unoccupied molecular orbitals were mainly composed of N^N ligand, therefore, the lowest-lying energy absorptions and emissions of 1 and 2 are attributed to the MLCT transition mixed with some LLCT transition characters. The high energy characters, however, the complexes 1 and 2 displayed absorptions are also manifested as transition different types of excited state.

关 键 词：锇(Ⅱ)二甲亚砜配合物 激发态结构 含时密度泛函 光谱特征 

分 类 号：O641.3[理学—物理化学]