The first report of the reaction of Davy’s reagent with [CpMo(CO)n]2 (n = 2,3) via a phosphorus–sulfur bond cleavage process. Isolation and characterization of CpMo(CO)2(S2P(SPhMe)2), Cp2Mo2(CO)5(S2P(SPhMe)) and Cp2Mo2(μ-S)(μ-S2)(μ-SPhMe) (Cp = (η5-C5H5))

The reaction of [CpMo(CO)3]2 (1) and its congener, the triply bonded [CpMo(CO)2]2 (2) with 2,4-bis(p-tolylthio)1,3-dithia-2,4-diphosphetane-2,4-disulfide (DR, Davy’s reagent) in toluene at 110 and 70 °C, respectively, led to the isolation of dark brown solids of CpMo(CO)2(S2P(SPhMe)2) (3), deep pink solids of Cp2Mo2(CO)5(S2P(SPhMe)) (4) and dark purple solids of Cp2Mo2(μ-S)(μ-S2)(μ-SPhMe) (5) with yields dependent on reaction conditions. Thermolytic studies followed by 1H NMR indicated that 3 and 4 had degraded to 5. The postulated mechanism involves P–S bond cleavage in DR leading to a ring opening and desulfurization process.

Graphical abstractReaction of [CpMo(CO)3]2 (1) and its congener, the triply bonded [CpMo(CO)2]2 (2) with 2,4-bis(p-tolylthio)1,3-dithia-2,4-diphosphetane-2,4-disulfide (DR, Davy’s reagent) in toluene at 110 and 70 °C, respectively, had led to the isolation of CpMo(CO)2(S2P(SPhMe)2) (3), Cp2Mo2(CO)5(S2P(SPhMe)) (4) and Cp2Mo2(μ-S)(μ-S2)(μ-SPhMe) (5). The synthetic pathway postulated in this study indicates that DR had undergone P–S bond cleavage leading to ring opening and desulfurization process.Figure optionsDownload full-size imageDownload as PowerPoint slide