多齿配体用于第14族元素的四亚甲基-低价衍生物的热力学稳定(E=Si,Ge,Sn,Pb)。这项工作通过DFT计算显示了结构(存在或不存在取代基)和类型(醇,Alk,或酚醛,Ar)三齿配体2,6-吡啶双(1,2-乙醇)[AlkONOR]H2和2,6-吡啶双(1,2-酚)[ArONOR]H2(R=H,Me)可能会影响乙炔的反应性或稳定性,表明主要群体元素前所未有的行为。这使得能够对发生的反应的类型进行独特的控制。我们发现不受阻碍的[OOH]H2配体主要导致超配位的双配体{[OOH]}2Ge络合物,其中将E(+2)中间体插入ArO-H键中,随后放出H2。相比之下,取代的[ONOMe]H2配体给出[ONOMe]Ge:胚层,它们可以被认为是动力学稳定的产物;它们转化为E(4)物种在热力学上也是有利的。酚类[ArONO]H2配体的后一反应比醇的[AlkONO]H2更可能发生。还研究了反应的热力学和可能的中间体。
Polydentate ligands are used for thermodynamic stabilization of tetrylenes-low-valent derivatives of Group 14 elements (E = Si, Ge, Sn, Pb). This work shows by DFT calculations how the structure (the presence or absence of substituents) and type (alcoholic, Alk, or phenolic, Ar) of tridentate ligands 2,6-pyridinobis(1,2-ethanols) [AlkONOR]H2 and 2,6-pyridinobis(1,2-phenols) [ArONOR]H2 (R = H, Me) may affect the reactivity or stabilization of tetrylene, indicating the unprecedented behavior of Main Group elements. This enables the unique control of the type of the occurring reaction. We found that unhindered [ONOH]H2 ligands predominantly led to hypercoordinated bis-liganded {[ONOH]}2Ge complexes, where an E(+2) intermediate was inserted into the ArO-H bond with subsequent H2 evolution. In contrast, substituted [ONOMe]H2 ligands gave [ONOMe]Ge: germylenes, which may be regarded as kinetic stabilized products; their transformation into E(+4) species is also thermodynamically favorable. The latter reaction is more probable for phenolic [ArONO]H2 ligands than for alcoholic [AlkONO]H2. The thermodynamics and possible intermediates of the reactions were also investigated.