A simple cluster–ligand interaction model is introduced to describe the surface passivation of bimetallic gold clusters by SUP (Thioureidopeptide) and SeUP (Selenoureidopeptide) ligands. The conformational search based on neutral peptide binding modes and their computed interaction energies show the existence of various structural isomers within 10 kcal mol⁻¹. Further, the negatively charged deprotonated peptide was found to strongly interact with metal cluster through the carboxylate unit. Irrespective of the mode of binding and configuration the metal cluster found to exist in parent geometry in all three charge states. The calculated HOMO-LUMO gap of ligated clusters predicts an increase in chemical stability after the ligation. Moreover, the ligation was found to decrease the energy required for oxidation and reduction. The excited-state calculations indicate absorption maxima at 200–400 nm corresponds to the LMCT transition. In all the hybrid cluster models the donor and acceptor end of the peptide were found to remain intact. However, the charge migration dynamics observed only in the homo-metallic gold-ligand hybrids, owing to the larger charge separation.

介绍了一个简单的簇-配体相互作用模型来描述SUP（硫脲肽）和SeUP（硒脲肽）配体对双金属金簇的表面钝化。基于中性肽结合模式的构象搜索及其计算的相互作用能表明，在10 kcal mol ^-1之内存在各种结构异构体。此外，发现带负电荷的去质子化的肽通过羧酸酯单元与金属簇强烈相互作用。不论结合和构型的模式如何，金属簇在所有三种电荷状态下都存在于母体几何中。所计算的连接簇的HOMO-LUMO缺口预测了连接后化学稳定性的提高。此外，发现连接减少了氧化和还原所需的能量。激发态计算表明，在200–400 nm处的吸收最大值对应于LMCT跃迁。在所有杂种簇模型中，发现肽的供体和受体末端保持完整。然而，由于较大的电荷分离，仅在均金属金-配体杂化物中观察到了电荷迁移动力学。