Tetrylones: An Intriguing Class of Monoatomic Zero‐valent Group 14 Compounds

Abstract

Tetrylones (ylidones) represent a class of zero-valent group 14 compounds with the general formula EL (E=C, Si, Ge, Sn, or Pb; L=neutral σ-donating ligand), wherein the tetrel atom, E(0), possess its four valence electrons in the form of two electron lone pairs, and is moreover coordinated by two ligands (L) via donor-acceptor interactions (L→E←L). This review focuses on the synthesis, structure, reactivity, and computational examination of the isolable heavier tetrylones (Si, Ge, Sn) that have been discovered recently. A comprehensive review on carbone chemistry is beyond the scope of this review. It should also be noted that tetrylones contain two different types of lone pairs, that is, one that exhibits p-type and one that exhibits s-type characteristics. Different behavior should thus be expected when these lone pairs react with Lewis acids.

A sandwich-type cluster containing Ge@Pd3 planar fragment flanked by aromatic nonagermanide caps

“…4 . It was found that the overall charges of Ge 9 fragments are −1.6 a.u., while the central Ge-atom bears slightly positive close to zero charge, which were classically found in organogermanium complexes and stabilized by carbine ligands that donate electron pairs into their empty orbitals 35 – 39 . Thus, the natural population analysis is in a good agreement with our assumption of zerovalent central Ge-atom stabilized by two [Ge 9 ] 2− ligands.…”

Bis(silylene)‐Stabilized Monovalent Nitrogen Complexes

“…This donor‐acceptor concept is not limited to carbon but applicable to its heavy congeners of Group 14. Several interesting tetrylone systems L→:E:←L (E=Si, Ge, Sn) have thus been developed [10–12] . Since nitrogen(I) is isoelectronic to carbon(0), the donor‐stabilized N I in [L→:N:←L] + , named as nitreones (Scheme 1), [13] has also gained considerable attention [14–16] .…”

“…L (E = Si, Ge, Sn) have thus been developed. [10][11][12] Since nitrogen(I) is isoelectronic to carbon(0), the donor-stabilized N I in [L!DND ! L] + , named as nitreones (Scheme 1), [13] has also gained considerable attention.…”

NHC‐Stabilised Silyliumylidene Ions

“…In recent years, low‐valent silicon species have grown in prominence in main group chemistry. Along with greater numbers of and more facile access to known classes of compounds such as silenes and silylenes, new classes such as silylones have also been isolated and investigated. Within this broader area, silyliumylidene ions have emerged as interesting reactive intermediates.…”