Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Trieste, Via Giorgieri 1, 34127 Trieste, Italy.
Phys Chem Chem Phys. 2019 Feb 13;21(7):3585-3596. doi: 10.1039/c8cp04107e.
TDDFT simulations of the absorption and CD spectra of a Pd2Au36(SC2H4Ph)24 monolayer-protected cluster (MPC) are carried out with the aim of investigating the effects of doping, conformational degrees of freedom of the thiolates' end-groups, and charge states on the optical and dichroic response of a prototypical MPC species. Clear signatures of Pd doping in both absorption and CD spectra are found to be a consequence of the participation of Pd (4d) states in the ligand-based d-band and on the unoccupied MOs of lower energy. Exploration of conformational space points to a much greater sensitivity of optical rotation to the conformation of the end-groups of the organic monolayer compared to absorption. Finally, the effect of charge is mainly seen as a decreased dependence of the dichroic response on conformation. The agreement between the TDDFT predictions and the available experimental data is good, and enables an assignment of absorption and CD bands to specific classes of one-particle excitations.
采用 TDDFT 方法模拟了 Pd2Au36(SC2H4Ph)24 单层保护簇（MPC）的吸收和圆二色（CD）光谱，旨在研究掺杂、硫醇末端基团的构象自由度以及荷电状态对典型 MPC 物种的光学和圆二色响应的影响。发现掺杂钯在吸收和 CD 光谱中都有明显的特征，这是由于 Pd（4d）态参与配体的 d 带和较低能量的空 MO 的结果。对构象空间的探索表明，与吸收相比，光学旋转对有机单层末端基团的构象更为敏感。最后，电荷的影响主要表现为对构象的圆二色响应的依赖性降低。TDDFT 预测与现有实验数据吻合良好，能够将吸收和 CD 带分配给特定的单粒子激发类型。
