摘要
Metal complexes with excellent nonlinear optical（NLO） properties have attracted considerable attention. The geometry structure, electronic spectra and NLO properties of 2,2？-bidipyrrins（L） and mono-and bimetal Ir（I）/Rh（I）–L complexes have been investigated by density functional theory method. Our calculations revealed that L with planar configuration shows the largest first hyperpolarizability value, which is 2.2 to 5.5 times larger than that of others. It is attributed to the single direction of intramolecular charge transfer. When metal ions were embedded in ligands, the first hyperpolarizability values of mono-and bimetal Ir/Rh（I）–L complexes were smaller than that of L, and that of bimetal Ir/Rh（I）–L complexes were smaller than the corresponding monometallic Ir/Rh（I）–L. This is caused by the intramolecular charge transfer from multiple directions as well as the amount of charge transfer. On the other hand, on increasing the number of metal ions, the charge transfer in the opposite direction cancels each other more obviously. Our work would provide some theoretical reference for the second-order NLO responses of mono-and bimetal complexes.
Metal complexes with excellent nonlinear optical（NLO） properties have attracted considerable attention. The geometry structure, electronic spectra and NLO properties of 2,2？-bidipyrrins（L） and mono-and bimetal Ir（I）/Rh（I）–L complexes have been investigated by density functional theory method. Our calculations revealed that L with planar configuration shows the largest first hyperpolarizability value, which is 2.2 to 5.5 times larger than that of others. It is attributed to the single direction of intramolecular charge transfer. When metal ions were embedded in ligands, the first hyperpolarizability values of mono-and bimetal Ir/Rh（I）–L complexes were smaller than that of L, and that of bimetal Ir/Rh（I）–L complexes were smaller than the corresponding monometallic Ir/Rh（I）–L. This is caused by the intramolecular charge transfer from multiple directions as well as the amount of charge transfer. On the other hand, on increasing the number of metal ions, the charge transfer in the opposite direction cancels each other more obviously. Our work would provide some theoretical reference for the second-order NLO responses of mono-and bimetal complexes.
基金
Supported by the National Natural Science Foundation of China(No.21173035)
the “12th Five-Year” Science and Technology Research Project of the Education Department of Jilin Province([2016]494)
