1. In this manuscript, it is shown that reactions of the ligands L mpz SSL mpz and L 3 SSL 3 with cobalt(II) bromide or chloride afford the expected cobalt(II)-disulfide complexes [1 Br ] and [3 Cl ]. The structure of [1 Br ] is unusual, as in contrast to the expected 5-coordinate geometry of the cobalt(II) ions, one of the cobalt(II) centers is in an octahedral geometry due to coordination of one of the disulfide sulfur atoms. Similar asymmetric structures were reported for [Fe 2 (L 1 SSL 1 )Cl 4 ] and for the polymeric compound [Cu 2 (L mpz SSL mpz )(CH 3 CN) 2 (BF 4 ) 2 ] n (BF 4 ) 2n [7, 11]. So far, there are only two reports on similar asymmetric compounds with cobalt(II) centers (coordination of one of disulfide sulfur atom to one cobalt, the other sulfur atom is not coordinated to any metal);Discussion Study of the reactivity of various Co(II)-disulfide compounds is of importance, as understanding of their reactivity may provide a rationale on redox-conversion reactions occurring in biology
2. However, with the ligands L mpz SSL mpz and L p SSL p the use of cobalt(II) thiocyanate does not afford the expected Co(III)-thiolate compounds but instead the dinuclear Co(II)-disulfide compounds [1 NCS ] and [2 NCS ] were formed, similar to the reactions with the ligand L 2 SSL 2 [8]. Based on electrochemical data, it has been suggested that the ligand L mpz SSL mpz has a stabilizing effect on the Cu(I)-disulfide system [11]. The stabilization of low oxidation states by the ligand L mpz SSL mpz seems to hamper formation of the Co(III)-thiolate complex starting from L mpz SSL mpz , even with the use of the strong ligand-field NCS ? ion. We anticipated that the reaction of the ligand L p SSL p with Co(SCN) 2 would produce a cobalt;Reaction of cobalt
3. Thiol/Disulfide Redox Switches in the Regulation of Heme Binding to Proteins