Synthesis, Structure, and Reactivities of Iminosulfane‐ and Phosphane‐Stabilized Carbones Exhibiting Four‐Electron Donor Ability

Abstract

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.

Synthesis, Electronic Structure, and Reactivities of Two‐Sulfur‐Stabilized Carbones Exhibiting Four‐Electron Donor Ability

“…In an attempt to extend of the coordination chemistry of two‐sulfur‐stabilized carbones, we synthesized silver complexes bearing 1 , E , and F as ligands and applied them as the carbone transfer reagents. Previously, we have reported the facile preparation of silver carbone complexes through an in situ deprotonation/complexation reaction . Here, by an analogous method, reactions of the hydrochloric salts of 1 , E , and F with Ag 2 O in dichloromethane were performed under air.…”

Metalated Ylides: A New Class of Strong Donor Ligands with Unique Electronic Properties

“…8 In the case of CDPs, recent studies have proven their unique reactivity, which makes them highly attractive as carbon bases. For example, hexaphenylcarbodiphosphorane was found to undergo adduct formation with small molecules or ions such as CO 2 , BH 3 , or GeCl + 9 or can be used as a ligand in transition-metal complexes 10 or in bond activation reactions.…”

Phosphine/Sulfoxide‐Supported Carbon(0) Complex

“…The P1−C1 bond length [1.6563(13) Å] in 2 is significantly shorter than in 1 [1.7190(15) Å] and the value remains slightly longer than those reported for CDPs (1.584–1.648 Å) . The S1−C1 bond length also undergoes significant shortening upon deprotonation [from 1.6539(15) Å in 1 to 1.5929(14) Å in 2 ], this value is the shortest S−C bond length reported to date in the sulfur‐stabilized carbone series (1.602–1.713 Å) ,. The S1−O1, S1−C16, and S1−C22 bond lengths get slightly longer (Δ S−X max=+0.02 Å).…”

“…The C−Au bond lengths [2.056(4) and 2.071(4) Å] are shorter than those observed in the related carbodisphosphorane‐ and carbodicarbene‐diaurated complexes (2.074, 2.078 Å and 2.080, 2.103 Å respectively). The aurophilic interaction is classical with Au1‐Au2 distance of 3.018(1) Å, which is in the range of other gem ‐diaurated carbones (2.952–3.143 Å) . Finally, the P1−C1 [1.781(4) Å] and the S1−C1 [1.737(4) Å] bonds lengths are significantly longer than in 1 , typical for single bonds (P−C: 1.79–1.82 Å and S−C: 1.73–1.75 Å) confirming that the two lone pairs are involved in the formation of complex 4 .…”

“…The variation of Wiberg bond indices ongoing from 1 to 2 (for P1−C1: +0.266, C1−S1: +0.241 and S1−O1: −0.089) correlates with the measurement obtained from the X‐ray data (for ΔP1−C1: −0.0627 Å, ΔC1−S1: −0.0610 Å and ΔS1−O1: +0.0145 Å) . The central carbon atom in 2 bears a large negative charge (−1.388) similarly to iminosulfane/phosphine‐carbone (−1.38) . The two highest occupied molecular orbitals (HOMO−1 n σC , HOMO n πC ) correspond to the two lone pairs at the central carbon in 2 (Figure ).…”