Synthesis and reactivity of bridging thiolato-manganese carbonyl complexes, Et 4N[Mn 2(μ-SR) 3(CO) 6

Abstract

The yellow-orange complexes Et 4N[Mn 2(μ-SR) 3(CO) 6] (R = Ph, Me, Bu t) have been prepared by several routes, including: (1) reactions of Et 4N[MnBr 2(CO) 4] with Bu 3SnSR; (2) reactions of Et 4N[Mn 2(μ-Br) 3(CO) 6] with either Bu 3SnSR, RSH, or NaSPh; and (3) reactions of Mn 2(μ-X) 2(CO) 8 (X = Br, SPh) with NaSPh, followed by metathesis using [Et 4N]Cl. The complex Et 4N[Mn 2(μ-SBu t) 3(CO) 6] can be converted to Et 4N[Mn 2(μ-SPh) 3(CO) 6] by reaction with PhSH in the presence of either a base (pyridine) or an acid (CF 3CO 2H or CH 3CO 2H). These bridging thiolate complexes, Et 4N[Mn 2(μ-SR) 3(CO) 6], undergo reactions with [Me 3O]BF 4 (or other electrophilic reagents) to give [Mn(CO) 3(μ-SR)] 4; if the same reactions are carried out in the presence of CO, Mn 2(μ-SR) 2(CO) 8 is the product. Similarly, reactions of Et 4N[Mn 2(μ-SR) 3(CO) 6] with [Me 3O]BF 4 in the presence of a phosphine (PMe 3, dppm) produce the phosphine substituted species, cis-Mn 2(μ-SR) 2(CO) 6(PMe 3) 2 and Mn 2(μ-SR) 2(CO) 6(μ-dppm); the former is converted upon heating to the known species Mn 2(μ-SR) 2(μ-CO)(CO) 4(PMe 3) 2.