氮化锇配合物离子[OsN(mnt)2]-的电子结构和光谱性质的理论研究

理论研究了离子型配合物OsN(mnt)2]-mnt=S2C2(CN)2)]的电子结构和光谱性质, 考察不同配体三价N、二硫氰烯S2C2(CN)2和金属Os的相互作用对光化学性质的影响. 分别在B3LYP/LANL2DZ和CIS/LANL2DZ水平上优化了配合物的基态和激发态结构. 与基态(1A1)相比, 激发态(3A2)的Os≡N 的键长缩短了0.0066 nm, 这与计算得到的频率增大一致, 使用TD-DFT方法计算得到了配合物的吸收和发射光谱. 计算得到的位于300 nm(f=0.1497)和262 nm(f=0.2890)的强吸收都来自1A1→1B1跃迁, 分别指认为SC→Os≡N+CN 和N+SC→Os≡N+CN的电子跃迁. 最低能量的吸收位于446 nm(f=0.0206) 处, 来自1A1→1B2的电子跃迁, 指认为N→Os和 N+SC→CN. 计算得到配合物在气态的磷光发射位于678 nm(A3A2→X1A1)处, 而在丙酮溶液中则蓝移到了625 nm处, 跃迁属性不变, 都是N→Os和S→Os的跃迁.

Theoretical Studies on Electron Structures and Spectroscopic Properties of Complex [OsN(mnt)2]-

Electronic structures and Spectroscopic properties of nitridoosmium(Ⅵ) complex ion, OsN(mnt)2]- were studied theoretically, and the influence of interaction of the ligandthree bond N and dithiolene S2C2(CN)2] and the metal(OsⅥ) on the character of photochemistry was investigated. The structures of the complexes were fully optimized at the B3LYP/LANL2DZ and CIS/LANL2DZ levels for the ground states and excited states, respectively. The bond length of Os≡N bond is shorted by ca. 0.066 nm in the A3A2 excited state in comparison with the X1A1 ground state, which is consistent with a higher vibration frequency of ν(Os—N) in the excited state than that in the ground state. We obtain the excited energy and the character of the charge transition of the absorption and emission under TD-DFT calculation. The intense absorptions at 300 nm and 262 nm were attributed to SC→Os≡N+CN and N+SC→Os≡N+CN, respectively. The lowest energy absorptions at λmax=446 nm were assigned as N→Os and N+SC→CN. The calculated phosphorescence emissions at λmax=678 nm(A3A2→X1A1) were originated from N→Os and S→Os, the emission properties does not alter in the solvent acetonitrile. However, the emission blue-shifted to 625 nm.