D'Alessandro Deanna M, Keene F Richard
School of Pharmacy and Molecular Sciences, James Cook University, Townsville, Queensland 4811, Australia.
Chem Soc Rev. 2006 May;35(5):424-40. doi: 10.1039/b514590m. Epub 2006 Feb 8.
Mixed-valence chemistry has a long and rich history which is characterised by a strong interplay of experimental, theoretical and computational studies. The intervalence charge transfer (IVCT) transitions generated in dinuclear mixed-valence species (particularly of ruthenium and osmium) have received considerable attention in this context, as they provide a powerful and sensitive probe of the factors which govern electronic delocalisation and the activation barrier to intramolecular electron transfer. This tutorial review discusses classical, semi-classical and quantum mechanical theoretical treatments which have been developed over the past 35 years for the analysis of IVCT absorption bands. Particular attention is drawn to the applicability of these models for the analysis of mixed-valence complexes which lie between the fully localised (Class II) and delocalised (Class III) limits in the "localised-to-delocalised" (Class II-III) regime. A clear understanding of the complex interplay of inter- and intramolecular factors which influence the IVCT process is crucial for the design of experimental studies to probe the localised-to-delocalised regime and in guidance of the development of appropriate theoretical models.
混合价态化学有着悠久而丰富的历史，其特点是实验、理论和计算研究之间存在强烈的相互作用。在这种情况下，双核混合价态物种（特别是钌和锇）中产生的价间电荷转移（IVCT）跃迁受到了相当多的关注，因为它们为控制电子离域和分子内电子转移活化能垒的因素提供了一个强大而灵敏的探针。本教程综述讨论了在过去35年中为分析IVCT吸收带而开发的经典、半经典和量子力学理论处理方法。特别关注这些模型在分析处于“局域化到离域化”（II-III类）区域中完全局域化（II类）和离域化（III类）极限之间的混合价态配合物时的适用性。清楚地理解影响IVCT过程的分子间和分子内因素的复杂相互作用，对于设计探测局域化到离域化区域的实验研究以及指导适当理论模型的发展至关重要。
