Smith George W A, Neale Samuel E, Evans Matthew J, Li Xuning, Wang Junhu, Gardiner Michael G, McMullin Claire L, Fulton J Robin, Coles Martyn P
School of Chemical and Physical Sciences, Victoria University of Wellington, PO Box 600, Wellington, 6012, New Zealand.
Department of Chemistry, University of Bath, Bath, BA2 7AY, U.K.
Chemistry. 2024 Nov 21:e202404206. doi: 10.1002/chem.202404206.
The potassium aluminyl K[Al(NON)] ([NON]=[O(SiMeNDipp)], Dipp=2,6-iPrCH) reacts with group 14 chloroamidinates E(Am)Cl (E=Ge, Sn, Pb. [Am]=[tBuC(NDipp)]) to form (NON)Al-E(Am) Lewis pairs with unsupported Al-E bonds, including the first structurally authenticated Al-Pb bond. Analysis using spectroscopic (NMR, UV-vis and Mössbauer for E=Sn), X-ray diffraction and computational (DFT, QTAIM, TD-DFT) methods conclude an Al-E σ-bond derived from a Lewis basic Al and a Lewis acidic tetrylene, with back-donation from the E s-orbital lone pair donor NBO to acceptor NBOs on Al that are derived from s/p-orbitals. The reaction of the Al-Ge compound with CO forms the dioxocarbene (NON)Al(μ-OC)Ge(Am), whilst under the same conditions the Al-Sn compound reacts with additional CO to form the carbonate, (NON)Al(μ-CO)Sn(Am). Addition of ethene to the Al-E (E=Ge, Sn) compounds introduces an ethylene bridge between the aluminium and group 14 atoms forming a frustrated Lewis pair (FLP). Reaction of the (Al/Ge) FLP with CO forms an activation product with new Al-O and Ge-C bonds, whilst reaction with iPrN=C=NiPr proceeds with insertion into the Al-C bond to form an aluminium amidinate.
铝钾基化合物K[Al(NON)]（[NON]=[O(SiMeNDipp)]，Dipp=2,6-二异丙基苯基）与第14族氯代脒盐E(Am)Cl（E=Ge、Sn、Pb，[Am]=[tBuC(NDipp)]）反应，形成具有未配位Al-E键的(NON)Al-E(Am)路易斯对，包括首个经结构验证的Al-Pb键。使用光谱方法（对于E=Sn，采用NMR、UV-vis和穆斯堡尔谱）、X射线衍射和计算方法（DFT、QTAIM、TD-DFT）分析得出，Al-E σ键源自路易斯碱Al和路易斯酸四价烯，且存在从E s轨道孤对供体NBO到Al上源自s/p轨道的受体NBO的反馈π键。Al-Ge化合物与CO反应生成二氧卡宾(NON)Al(μ-OC)Ge(Am)，而在相同条件下，Al-Sn化合物与额外的CO反应生成碳酸盐(NON)Al(μ-CO)Sn(Am)。向Al-E（E=Ge、Sn）化合物中加入乙烯，会在铝和第14族原子之间引入一个乙烯桥，形成受阻路易斯对（FLP）。(Al/Ge) FLP与CO反应形成具有新的Al-O和Ge-C键的活化产物，而与iPrN=C=NiPr反应则通过插入Al-C键形成铝代脒。
