Designing a Solution-Stable Distannene: The Decisive Role of London Dispersion Effects in the Structure and Properties of {Sn(C 6 H 2 -2,4,6-Cy 3 ) 2 } 2 (Cy = Cyclohexyl)
Designing a Solution-Stable Distannene: The Decisive Role of London Dispersion Effects in the Structure and Properties of {Sn(C 6 H 2 -2,4,6-Cy 3 ) 2 } 2 (Cy = Cyclohexyl)
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设计溶液稳定的二锡烯：伦敦色散效应对 {Sn(C 6 H 2 -2,4,6-Cy 3 ) 2 } 2 (Cy = 环己基) 结构和性能的决定性作用
DOI：
10.1021/jacs.1c09976
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发表时间：
2021
影响因子：
15
通讯作者：
Power, Philip P.
中科院分区：
文献类型：
--
作者：
Stennett, Cary R.;Bursch, Markus;Fettinger, James C.;Grimme, Stefan;Power, Philip P.
1当量的新型伦敦色散效应供体配体{Li(C6H2-2,4,6-Cy3)·OEt2}2(Cy=环己基)的二聚锂盐与SnCl2反应得到二锡烯{Sn(C6H2-2,4,6-Cy3)2}2(1)。二锡烯在溶液中保持二聚体，如其室温 119Sn NMR 信号（δ = 361.3 ppm）及其电子光谱所示，电子光谱在 -10 至 100 °C 的温度范围内保持不变。与其他二锡烯相比，二锡烯的 Sn-Sn 距离较短，为 2.7005(7) Å，并且在溶液中的稳定性大大增强，其形成是由于配体 C-H 部分在 Sn-Sn 键上的多个紧密接近而产生的配体间伦敦色散 (LD) 吸引力的增加。 DFT-D4 计算显示二聚体 1 的分散稳定性为 38 kcal mol–1，二聚自由能为 ΔGdimer= -6 kcal mol–1。相比之下，2当量形状相似但体积较小、富氢较少的Li(C6H2-2,4,6-Ph3)·(OEt2)2与SnCl2反应生成单体亚锡Sn(C6H2-2,4,6-Ph3)2(2)，其在环境温度下在溶液中不稳定。
The reaction of 1 equiv of the dimeric lithium salt of a new London dispersion effect donor ligand {Li(C6H2-2,4,6-Cy3)·OEt2}2(Cy = cyclohexyl) with SnCl2afforded the distannene {Sn(C6H2-2,4,6-Cy3)2}2(1). The distannene remains dimeric in solution, as indicated by its room-temperature119Sn NMR signal (δ = 361.3 ppm) and its electronic spectrum, which is invariant over the temperature range of −10 to 100 °C. The formation of the distannene, which has a short Sn–Sn distance of 2.7005(7) Å and greatly enhanced stability in solution compared to that of other distannenes, is due to increased interligand London dispersion (LD) attraction arising from multiple close approaches of ligand C–H moieties across the Sn–Sn bond. DFT-D4 calculations revealed a dispersion stabilization of dimer1of 38 kcal mol–1and a dimerization free energy of ΔGdimer= −6 kcal mol–1. In contrast, the reaction of 2 equiv of the similarly shaped but less bulky, less hydrogen-rich Li(C6H2-2,4,6-Ph3)·(OEt2)2with SnCl2yielded the monomeric stannylene Sn(C6H2-2,4,6-Ph3)2(2), which is unstable in solution at ambient temperature.