The reaction of MnBr2 and [PPN](2)[S1S-C6H3-R] (1:2 molar ratio) in THF yielded [(THF)Mn(S,S-C6H3-R)(2)](-) [R = H (1a), Me (1b); THF = tetrahydrofuran]. Formation of the dimeric [Mn(S,S-C6H3-R)(2)](2)(2-) [R = H (2a), Me (2b)] was presumed to compensate for the electron-deficient Mn-III core via two thiolate bridges upon dissolution of complexes 1a and 1b in CH2Cl2. Complex 2a displays antiferromagnetic coupling interaction between two Mn-III centers (J = -52 cm(-1)), with the effective magnetic moment (mu eff) increasing from 0.85 mu(B) at 2.0 K to 4.86 mu(B) at 300 K. The dianionic manganese(II) thiolate complexes [Mn(S,S-C6H3-R)(2)](2-) [R = H (3a), Me (3b)] were isolated upon the addition of [BH4](-) into complexes la and 1b or complexes 2a and 2b, respectively. The anionic mononuclear (Mn(NO)}(5) thiolatonitrosylmanganese complexes [(NO)Mn(S,S-C6H3-R)(2)](-) [R = H (4a), Me (4b)] were obtained from the reaction of NO(g) with the anionic complexes la and 1b, respectively, and the subsequent reduction of complexes 4a and 4b yielded the mononuclear {Mn(NO)}(6) [(NO)Mn(S,S-C6H3-R)(2)](2-) [R = H (5a), Me (5b)]. X-ray structural data, magnetic susceptibility measurement, and magnetic fitting results imply that the electronic structure of complex 4a is best described as a resonance hybrid of [(L)(QMn(III)(NO center dot)](-) and [(L)(L-center dot)Mn-III(NO-)](-) (L = 1,2-benzenedithiolate) electronic arrangements in a square-pyramidal ligand field. The lower IR nu(NO) stretching frequency of complex 5a, compared to that of complex 4a (shifiing from 1729 cm(-1) in 4a to 1651 cm-1 in 5a), supports that one-electron reduction occurs in the {(L)(L-center dot)Mn-III} core upon reduction of complex 4a.