[Au(PH3)]^＋修饰下苯的激发态性质的理论研究

Theoretical Study of Excited States Properties of Phenyl Modified [Au(PH_3)]^+

用MP2和CIS方法分别优化了H3PAuPh(a)、对位(H3PAu)2C6H4(b)和间位(H3PAu)3C6H3(c)的基态和激发态结构.计算结果表明,[Au(PH3)]+的引入使Au(Ⅰ)配合物的苯环上的电子云密度降低,削弱了苯基内C—C键的成键作用.计算得到配合物a^c的最低能量磷光发射分别为443,461和429nm,均属于苯基为π*→π跃迁本质,并伴有Au(6p)→π(Ph)和Au(6p)→Au(5d)电荷转移性质.与苯的最低能量磷光发射(413nm)相比揭示了配合物a^c的发光过程是[Au(PH3)]+修饰的π*→π发光机制.

The structures in ground and lowest-energy triplet excited states for [ Au （PH3 ） ] C6H5 （a）, 1 ,4-bi （ AuPH3 ） -C6 H4 （ b ） and 1,3,5-ter （ AuPH3 ） -C6 H3 （c） were optimized by the MP2 and CIS methods, respectively. It was shown that the introduction of [ Au （PH3 ） ]^＋ decreases the electron density around phenyl ring, which weakens the C-C bonding in the ring. The lowest-energy phosphorescences of a-c were predicted at 442. 7,461.3 and 428.9 nm by the CIS method, respectively. Comparison with that of benzene shows that the phosphorescent emissions of a-c exhibit the π^＊→π transition involved in the phenyl ring, accompanied by Au （ 6p ） →Ph and Au （ 6p ）→Au （5d） charge transfer transitions.