Au(Ⅰ)电荷转移配合物光谱性质的从头算研究

过渡金属电荷转移配合物的电荷分离是光能转化为电能的光物理过程, 与配合物的电子结构密切相关. 采用从头算方法探索了双核Au(Ⅰ)配合物, cis-Au2(SHCH2PH2)2]2+(1), cis-Au2(SHCH2S)2](2) 和cis-Au2(PH2CH2S)2](3)的电荷转移性质. 采用MP2计算得到基态的Au(Ⅰ)—Au(Ⅰ)距离分别为0.2972, 0.2888和0.2903 nm, 表明Au(Ⅰ)之间存在弱吸引作用; 电子激发使得配合物2和3的金属间的距离缩短了约0.016 nm, 而配合物1仅增长了0.002 nm. CIS方法预测配合物1~3的3A激发态分别产生383, 463和422 nm最低能发射, 具有金属中心(Metal-centered, MC)跃迁和分子内电荷转移(Intramolecular Charge Transfer, ICT)的混合性质.

Ab initio Studies on Spectroscopic Properties of Au(I) Charge-transfer Complexes

The process of charge separation of transition metal charge-transfer complexes involves the conversion of photo-energy into electrical energy, closely related to their electronic structures. We explored thecharge-transfer properties of binuclear Au(Ⅰ) complexes, cis-Au2(SHCH2PH2)2]2+(1), cis-Au2(SHCH2S)2](2) and cis-Au2(PH2CH2S)2](3), using ab initio methods. Their Au(Ⅰ)—Au(Ⅰ) distances in the ground states at the MP2 level are 0.2972, 0.2888 and 0.2903 nm, respectively, indicating the weak attraction between the two Au atoms. Upon excitation, those of complexes 2 and 3 are shortened by ca. 0.016 nm whereas that of complex 1 only elongates ca. 0.002 nm. CIS calculations predict that the triplet excited states of complexes 1—3 give rise to 383, 463 and 422 nm lowest-energy emissions, respectively. These emissions are attributable to the metal-centered(MC) transition mixed with the intramolecular charge transfer(ICT), which significantly differs from the cases in the previous studied on Au2(SHCH2SH)2]2+, trans-Au2(SHCH2PH2)2]2+ and Au2(PH2CH2PH2)2]2+.