Bhandari Mamta, Kaur Mandeep, Rawat Sandeep, Singh Sanjay
Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali Knowledge City, Sector 81, SAS Nagar, Mohali, 140306, Punjab, India.
Chemistry. 2023 Oct 2;29(55):e202301229. doi: 10.1002/chem.202301229. Epub 2023 Jul 25.
Herein, we report the synthesis of β-diketiminate-supported aluminium complexes bearing terminal alkoxide and mono-thiol functional groups: LAlOMe(Et) (2), LAlOtBu(Et) (3), and LAlSH(Et) (4), (L=[HC{C(Me)N-(2,6-iPr C H )} ]). Complexes 2 and 3 are further used as synthons to generate the fascinating cationic aluminium alkoxide complexes, [LAlOMe(μ-OMe)-Al(Et)L][EtB(C F ) ] (5), [LAlOMe(OEt )][EtB(C F ) ] (6), and [LAlOtBu(OEt )][EtB(C F ) ] (8). These electrophilic cationic species are well characterized by spectroscopic and crystallographic techniques. The assessment of Lewis acidity by the Gutmann-Beckett method revealed superior Lewis acidity of the cations substituted with electron-demanding alkoxy groups in comparison to the known methyl analogue [LAlMe][B(C F ) ]. This has been further endorsed by computational calculations to determine the NBO charges and hydride ion affinity for complexes 6 and 8. These complexes are also capable of activating triethylsilane in stoichiometric reactions. The applicability of these complexes has been realized in the hydrosilylation of ethers, carbonyls, and olefines. Additionally, the solid-state structure of a new THF stabilized aluminium halide cation [LAlCl(THF)][B(C F ) ] (11) has also been reported.
在此，我们报道了带有末端醇盐和单硫醇官能团的β-二酮亚胺基支持的铝配合物的合成：LAlOMe(Et) (2)、LAlOtBu(Et) (3) 和 LAlSH(Et) (4)，(L = [HC{C(Me)N-(2,6-iPr₂C₆H₃)}₂])。配合物2和3进一步用作合成子，以生成引人入胜的阳离子醇盐铝配合物，[LAlOMe(μ-OMe)-Al(Et)L][EtB(C₆F₅)₄] (5)、[LAlOMe(OEt₂)][EtB(C₆F₅)₄] (6) 和 [LAlOtBu(OEt₂)][EtB(C₆F₅)₄] (8)。这些亲电阳离子物种通过光谱和晶体学技术得到了很好的表征。通过古特曼-贝克特方法对路易斯酸度的评估表明，与已知的甲基类似物 [LAlMe][B(C₆F₅)₄] 相比，被吸电子醇氧基取代的阳离子具有更高的路易斯酸度。通过计算确定配合物6和8的自然键轨道 (NBO) 电荷和氢化物离子亲和力，进一步证实了这一点。这些配合物还能够在化学计量反应中活化三乙基硅烷。这些配合物在醚、羰基化合物和烯烃的硅氢化反应中的适用性已经得到了证实。此外，还报道了一种新的四氢呋喃稳定的卤化铝阳离子 [LAlCl(THF)][B(C₆F₅)₄] (11) 的固态结构。
