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A series of reactions between Lewis bases and an imidazole‐based dithione dimer (1) has been investigated. Both cyclic(alkyl)(amino)carbene (CAAC) (2) and N‐heterocyclic carbene (NHC) (4), in addition to N‐heterocyclic silylene (NHSi) (6), demonstrate the capability to cleave the sulphur–sulphur bonds in 1, giving carbene‐stabilized dithiolene (L0) zwitterions (3 and 5) and a spirocyclic silicon–dithiolene compound (7), respectively. The bonding nature of 3, 5, and 7 are probed by both experimental and theoretical methods. [ABSTRACT FROM AUTHOR]

This article highlights recent efforts of this laboratory in the stabilization of highly reactive, low-oxidation-state, main-group molecules using bulky N-heterocyclic carbene ligands [L: = :C{N(2,6-Pri2C6H3)CH}2; L′: = :C{N(2,4,6-Me3C6H2)CH}2; L″: = :C{(i-Pr)NC(Me)}2]. The syntheses, structures, and computational studies of carbene-stabilized neutral diborenes [L:(H)B-B(H):L and L′:(H)B-B(H):L′], a neutral Ga6 octahedron (L″:Ga[Ga4Mes4]Ga:L″), disilicon (L:Si-Si:L), bis-silylene [L:(Cl)Si-Si(Cl):L], dipnictogens (L:E-E:L, E = P, As; L′:P-P:L′), and parent phosphinidene (L:PH) are discussed. Some of the unique challenges associated with this "carbene-stabilization" strategy are also presented. [ABSTRACT FROM AUTHOR]

Reaction of thiolate 1 with carbene-stabilized diiodo-bis-silylene (2) (in a 2:1 ratio) in THF unexpectedly gives both the first five-membered, sulfur-containing, zwitterionic silylene ring (3) via insertion of the "Si2I" unit of 2 into the olefinic C--H bond of the imidazole ring of 1 and four-membered cyclic silylene (4) via insertion of a silicon(I) atom of 2 into the Cphenyl--N bond of the carbene ligand. The parallel reaction in toluene only gives 3 as the major product. The nature of the bonding in isomeric 3 and 4 was probed by experimental and theoretical methods. [ABSTRACT FROM AUTHOR]

While reaction of carbene-stabilized disilicon L:Si═Si:L (L: = C{N(2,6-iPr2C6H3)CH}2) (8) with HCl·NC5H5 results in carbene-stabilized Si2Cl2 (2) and substituted 1H-imidazole (9), combination of the corresponding Fe(CO)4-modified disilicon carbene complex L:Si═Si[Fe(CO)4]:L (6) with pyridine hydrochloride gives a species containing two push-pull-stabilized parent monochlorosilylenes that are bridged by an Fe(CO)3 unit (7). The nature of 7 was further elucidated by spectroscopic, crystallographic, and computational methods. Spectroscopic data suggest that 7 exists as two diastereoisomers. [ABSTRACT FROM AUTHOR]