Photochemical reaction of (CpCrCSMe 3) 2S (I) with CpMn(CO) 3 gave the complex (CpCrSCMe 3) 2S - Mn(CO) 2CP(II). According to X-ray analysis its fragments are joined by an MnS (sulfide) bond (2.334Å) with almost no change in geometry of complex I upon coordination (CrCr 2.704, CrS (sulfide) 2.29, CrS (thiolate) 2.35, CrC(Cp) 2.256 Å, 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 [Cp 3Cr 3(μ 3-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 (CpCrSCMe 3) 2S - M(CO) 3CP with respect to II. The known diamagnetic tetrahedral analog of III and IV, Cp 4Cr 4S 4 was obtained by pyrolysis of I.