Antiferrogmagnetic complexes with metal/3- metal bonds

Abstract Photochemical reaction of (CpCrCSMe3)2S (I) with CpMn(CO)3 gave the complex (CpCrSCMe3)2S - Mn(CO)2CP(II). According to X-ray analysis its fragments are joined by an MnS (sulfide) bond (2.334A) with almost no change in geometry of complex I upon coordination (CrCr 2.704, CrS (sulfide) 2.29, CrS (thiolate) 2.35, CrC(Cp) 2.256 A, CrS(sulfide)Cr 72.2°, CrS(thiolate)Cr 70.0°). However, the reaction of I with CPM(CO)4 (M  V, Nb) under the same conditions yielded the corresponding paramagnetic heteronuelear complexes [Cp3Cr3(μ3-S)4]MCP (III and IV, respectively) probably containing a tetrahedral metallic skeleton. The reason for the rearrangement of I in the latter reactions may be a greater steric hindrance in the intermediate complexes (CpCrSCMe3)2S - M(CO)3CP with respect to II. The known diamagnetic tetrahedral analog of III and IV, Cp4Cr4S4 was obtained by pyrolysis of I.