Cao Zexing, Zhang Qianer
Department of Chemistry, State Key Laboratory for Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, China.
Chemistry. 2004 Apr 19;10(8):1920-5. doi: 10.1002/chem.200305572.
Density functional theory and CASSCF calculations have been used to optimize the geometries of binuclear gold(I) complexes [H(3)PAu(C[triple bond]C)(n)AuPH(3)] (n=1-6) in their ground states and selected lowest energy (3)(pi pi*) excited states. Vertical excitation energies obtained by time-dependent density functional calculations for the spin-forbidden singlet-triplet transitions have exponential-decay size dependence. The predicted singlet-triplet splitting limit of [H(3)PAu(C[triple bond]C)(proportional/variant)AuPH(3)] is about 8317 cm(-1). Calculated singlet-triplet transition energies are in reasonable agreement with available experimental observations. The effect of the heavy atom Au spin-orbit coupling on the (3)(pi pi*) emission of these metal-capped one-dimensional carbon allotropes has been investigated by MRCI calculations. The contribution of the spin- and dipole-allowed singlet excited state to the spin-orbit-coupling wave function of the (3)(pi pi*) excited state makes the low-lying acetylenic triplet excited states become sufficiently allowed so as to appear in both electronic absorption and emission.
密度泛函理论和完全活性空间自洽场计算已被用于优化双核金（I）配合物[H₃PAu(C≡C)ₙAuPH₃]（n = 1 - 6）基态和选定的最低能量（³ππ*）激发态的几何结构。通过含时密度泛函计算得到的自旋禁阻单重态 - 三重态跃迁的垂直激发能具有指数衰减的尺寸依赖性。[H₃PAu(C≡C)ₓAuPH₃]预测的单重态 - 三重态分裂极限约为8317 cm⁻¹。计算得到的单重态 - 三重态跃迁能量与现有的实验观测结果合理吻合。通过多参考组态相互作用（MRCI）计算研究了重原子金的自旋 - 轨道耦合对这些金属封端的一维碳同素异形体的（³ππ*）发射的影响。自旋和偶极允许的单重激发态对（³ππ*）激发态的自旋 - 轨道耦合波函数的贡献使得低位的炔基三重激发态变得足够允许，从而出现在电子吸收和发射中。
