CAJ | 학술논문

采用密度泛函理论(DFT)方法对双环金属Ir(III)异腈配合物的非线性光学(NLO)性质进行计算研究。用B3PW91(UB3PW91)(金属原子采用LANL2DZ基组，非金属原子采用6-31G*基组)方法对配合物进行几何结构优化。在优化构型基础上，采用B3PW91(UB3PW91)和B3LYP(UB3LYP)方法计算了配合物的第一超极化率(βtot)，并用CAM-B3LYP(UCAM-B3LYP)(金属原子采用LANL2DZ基组，非金属原子采用6-31G**基组)方法模拟配合物的吸收光谱。结果表明，主配体的取代基(R1)和副配体的取代基(R2)对第一超极化率值贡献不大。配合物发生氧化还原反应，电荷转移方式增多，电荷转移程度增大，使βtot值显著增加，其中1a+([(C∧N)2Ir(CNR)2]+(R=CH3))发生氧化反应和还原反应的βtot值分别增大了75倍和144倍。因此，这类双环金属铱(III)异腈配合物的氧化还原反应可以有效地调节其二阶NLO性质。
채용밀도범함이론(DFT)방법대쌍배금속Ir(III)이정배합물적비선성광학(NLO)성질진행계산연구。용B3PW91(UB3PW91)(금속원자채용LANL2DZ기조，비금속원자채용6-31G*기조)방법대배합물진행궤하결구우화。재우화구형기출상，채용B3PW91(UB3PW91)화B3LYP(UB3LYP)방법계산료배합물적제일초겁화솔(βtot)，병용CAM-B3LYP(UCAM-B3LYP)(금속원자채용LANL2DZ기조，비금속원자채용6-31G**기조)방법모의배합물적흡수광보。결과표명，주배체적취대기(R1)화부배체적취대기(R2)대제일초겁화솔치공헌불대。배합물발생양화환원반응，전하전이방식증다，전하전이정도증대，사βtot치현저증가，기중1a+([(C∧N)2Ir(CNR)2]+(R=CH3))발생양화반응화환원반응적βtot치분별증대료75배화144배。인차，저류쌍배금속의(III)이정배합물적양화환원반응가이유효지조절기이계NLO성질。
The second-order nonlinear optical (NLO) properties of bis-cyclometalated iridium(III) isocyanide complexes were investigated by density functional theory (DFT). In this work, the geometries of the complexes were optimized using the B3PW91(UB3PW91) functional and they were found to be in good agreement with experimental data. The 6-31G*basis set was used for the non-metal elements while the LANL2DZ basis set was used for iridium. From the optimized geometries the total first hyperpolarizabilities (βtot) of the complexes were calculated by the B3PW91(UB3PW91) and B3LYP(UB3LYP) functionals. Because the polarization and diffuse function may have a nontrivial effect on the calculation of the first hyperpolarizabiliy the more flexible and polarized 6-31+G**non-metal atom basis sets and the LANL2DZ basis set for iridium were used. The absorption spectra of al the complexes were calculated at the CAM-B3LYP(UCAM-B3LYP)/6-31+G**(LANL2DZ iridium atom) level in acetonitrile to obtain a deeper insight into the second-order NLO properties of these complexes. The results indicate that the second-order NLO response is not strongly affected by different substituents, while the redox reaction plays an important role in improving the second-order NLO response and this comes from a change in the charge transfer pattern and an increase in the degree of charge transfer. Theβtot values of the one-electron oxidized/reduced species (1a2+/1a)(complexes cyclometalated with N-arylazolesand alkyl isocyanides, [(C∧N)2Ir(CNR)2]+(R=CH3)) are 75 and 144 times larger than that of the eigenstate complex (1a+), respectively. Therefore, the redox reaction of the cationic bis-cyclometalated iridium isocyanide complexes can effectively tune the second-order NLO properties.