The study of the nucleophilic degradation of S8 by the methanide complex [Mn(CO)4{(PPh2)2CH}] (2) has led to the preparation of a unique class of polysulfide derivatives of formula [(CO)4Mn{(Pph2)2C-Sn-C (Pph2)2}Mn(CO)4]. The Structures of 3 (n = 6), 4 (n = 2), and 7 (n = 1) have been determined by X-ray crystallography, whereas those polysulfides with the sulfur chains S7, S5, S4, and S3 have been detected by spectroscopic methods. The polysulfides with n > 2 lose sulfur spontaneously, a process that can be accelerated by treatment with Pph3 or Na/Hg. Complexes 3, 4, and 7 were protonated at the two methanide carbon atoms to give the cationic dinuclear derivatives [(CO)4Mn{(Pph2)2C(H)-Sn-C(H) (Pph2)2}Mn(CO)4]2+ (8, n = 6; 9, n = 2; 10, n = 1). The 1H NMR spectrum of 9 suggests the existence of intramolecular CH ··· S interactions, in agreement with the X-ray structural determination of this complex. By treatment of 4 and 7 with one equivalent of HBF4 it is possible to selectively protonate just one methanide carbon atom, which allows the isolation of the mixed cationic derivatives [(CO)4Mn{(Pph2)2C(H)Sn-C (Pph2)2}Mn(CO)4]+ (11, n = 2; 6, n = 1). Additionally, heterometallic complexes containing a bridging disulfide unit, of general formula [(CO)4Mn{(Pph2)2C(AuPPh3) S-SC(AuPPh3)(Pph2)2}Mn(CO)4] 2+ (12) and [(CO)4Mn{(Pph2)2C(H)S-SC (AuPPh3)(Pph2)2}Mn (CO)4]+ (13), were prepared by reaction of 4 and 11, respectively, with [AuCl(Pph3)] in the presence of TIPF6.