Datta Ayan, Mallajosyula Sairam S, Pati Swapan K
Theoretical Sciences Unit, Chemistry and Physics of Materials Unit and DST Unit on Nanoscience, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur Campus, Bangalore 560 064, India.
Acc Chem Res. 2007 Mar;40(3):213-21. doi: 10.1021/ar0682738.
All-metal clusters, such as Al(4)M(4) (M = alkali metal ion), exhibit interesting features of multi-fold aromaticity/antiaromaticity. Such characteristics arise particularly because of the poor sigma-pi separation in this class of systems. This Account presents computational strategies to unambiguously determine the aromaticity/antiaromaticity characteristics of such clusters. Computations of the linear and nonlinear optical responses show that all-metal clusters are orders of magnitude more polarized than the conventional pi-conjugated molecules. We also propose new strategies to stabilize all-metal antiaromatic systems through complexation to transition metals and discuss mechanisms for substitution reactions within the conventional organometallic systems by Al(4)M(4). Additionally, we find that these all-metal clusters form stacked superclusters that are extremely stable and aromatic.
全金属簇合物，如Al(4)M(4)（M = 碱金属离子），展现出有趣的多重芳香性/反芳香性特征。此类特性的出现尤其归因于这类体系中较差的σ-π分离。本综述介绍了明确确定此类簇合物芳香性/反芳香性特征的计算策略。线性和非线性光学响应的计算表明，全金属簇合物的极化程度比传统的π共轭分子高出几个数量级。我们还提出了通过与过渡金属络合来稳定全金属反芳香体系的新策略，并讨论了Al(4)M(4)在传统有机金属体系中进行取代反应的机制。此外，我们发现这些全金属簇合物形成了极其稳定且具有芳香性的堆叠超簇。
