Role of Group 13 Metals in the Electronic Properties of L(X)M-Substituted Pnictinidenes

Nitrenes are well-established in organic chemistry as reactive (intermediate) species, whereas heavier pnictinidenes have only recently become an emerging class of compounds due to their potential use in bond activation reactions and catalytic applications. We herein report on the synthesis of the Al- and In-substituted, carbene-coordinated pnictinidenes of the general type L(Cl)MPnMecAAC (L = HC[C(Me)N(Dipp)]2, Dipp = 2,6-i-Pr2C6H3; Pn = As, M = Al 1, In 2; and Pn = Sb, M = Al 3, In 4) by oxidative addition of monovalent group 13 diyls LM (M = Al, In) to MecAACPnCl. Compounds 1–4 were characterized by heteronuclear nuclear magnetic resonance spectroscopy (1H and 13C), while their solid-state structures were determined by single-crystal X-ray diffraction. Quantum chemical calculations gave a deeper insight into the electronic nature of pnictinidenes 1–4, and comparison to previously reported L(Cl)Ga-substituted homologues clearly revealed the influence of electropositive group 13 metals on their electronic nature.

氮宾（Nitrenes）作为活性中间体物种，在有机化学领域已得到广泛认可；而较重的氮族宾（pnictinidenes）因在化学键活化反应及催化应用中具备潜在用途，直至近年才成为一类新兴化合物。本文报道了通过将一价第13族二基物种LM（M=Al、In）与MecAACPnCl发生氧化加成反应，合成通式为L(Cl)MPnMecAAC的铝、铟取代且卡宾配位的氮族宾化合物：其中配体L=HC[C(Me)N(Dipp)]2，取代基Dipp=2,6-二异丙基苯基；当Pn为As时，M=Al对应化合物1、M=In对应化合物2；当Pn为Sb时，M=Al对应化合物3、M=In对应化合物4。通过异核核磁共振波谱法（1H和13C NMR）对化合物1~4进行了表征，并通过单晶X射线衍射（single-crystal X-ray diffraction）测定了其固态分子结构。量子化学计算（quantum chemical calculations）深入剖析了氮族宾化合物1~4的电子性质，并与此前报道的L(Cl)Ga取代的同系物进行对比，清晰揭示了电正性第13族金属对其电子性质的影响。