Synthesis and NMR characterization of cobalt(III) complexes with 1,8-diamino-3,6-dithiaoctane, 2,2-bipyridine, and 1,10-phenanthroline

The complexes [Co(eee)(biPY)]Cl-3 and [Co(eee)(phen)]Cl-3 (eee, 1,8-diamino-3,6-dithiaoctane) were synthesized and characterized by two-dimensional NMR spectroscopy. The presence of the bidentate aromatic ligands 2,2-bipyridine and 1,10-phenanthroline caused the H-1 resonances to be spread into a wider spectral width than previously observed for [Co(eee)(NO2)(2)]Cl and [Co(eee)Cl-2]Cl. Separate multiplets were observed for the four protons in the terminal ethylene linkage. It was possible to positively assign each multiplet and to determine the relative spatial orientations of the corresponding protons.