Iminosulfane(phosphane)carbon(0) derivatives (iSPCs; Ar3 P→C←SPh2 (NMe); Ar=Ph (1), 4-MeOC6 H4 (2), 4-(Me2 N)C6 H4 (3)) have been successfully synthesized and the molecular structure of 3 characterized. Carbone 3 is the first thermally and hydrolytically stable carbone stabilized by phosphorus and sulfur ligands. DFT calculations reveal the electronic structures of 1-3, which have two lone pairs of electrons at the carbon center. First and second proton affinity values are theoretically calculated to be in the range of 286.8-301.1 and 189.6-208.3 kcal mol(-1) , respectively. Cyclic voltammetry measurements reveal that the HOMO energy levels follow the order of 3>2>1 and the HOMO of 3 is at a higher energy than those of bis(chalcogenane)carbon(0) (BChCs). The reactivities of these lone pairs of electrons are demonstrated by the C-diaurated and C-proton-aurated complexes. These results are the first experimental evidence of phosphorus- and sulfur-stabilized carbones behaving as four-electron donors. In addition, the reaction of hydrochloric salts of the carbones with Ag2 O gives the corresponding Ag(I) complexes. The resulting silver(I) carbone complexes can be used as carbone transfer agents. This synthetic protocol can also be used for moisture-sensitive carbone species.

Bis(sulfane)carbon(0) (BSC; Ph S→C←SPh (1)) is successfully synthesized by deprotonation of the corresponding protonated salt 1⋅HTfO. The diprotonated salt 1⋅(HTfO) as the starting material can be also easily accessed by the deimination of iminosulfane(sulfane)carbon(0) (iSSC)⋅HBF . Density functional theory calculations revealed the peculiar electronic structure of 1, which has two lone pairs of electrons at the central carbon atom. The largest proton affinities (PA(1): 297.5 kcal mol ; PA(2): 183.7 kcal mol ) and the highest energy levels of the HOMOs (HOMO: -4.89 eV; HOMO-1: -5.02 eV) for 1 among the two-sulfur-stabilized carbones clearly indicate the strong donor ability of carbon center stabilized by two S ligands. The donating ability of these lone pairs of electrons is demonstrated by the C-diaurated and C-proton-aurated complexes, which provide the first experimental evidence for two-sulfurstabilized carbones behaving as four-electron donors. Furthermore, the syntheses and application of Ag carbone complexes as carbone transfer agents are also reported.

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