Synthetic, electrochemical, spectroscopic, and structural studies of mixed sandwich Co(III) complexes involving Cp or Cp* with tridentate N-donor and S-donor macrocycles

摘要

The syntheses, structures, spectroscopy, and electrochemistry for four Co(III) mixed sandwich mononuclear complexes involving tridentate macrocycles and either cyclopentadienyl (Cp) or pentamethylcyclopentadienyl (Cp*) are reported. All complexes have the general formula [Co(CpR)([9]aneX3)](PF6)2, where X?=?S, 1,4,7-trithiacyclononane, and R?=?Cp (1) or Cp* (2), or X?=?N, 1,4,7-triazacyclononane, and R?=?Cp (3) or Cp* (4), and exhibit a pseudo-octahedral structure involving the carbocyclic η5-CpRligand and facial κ3-donation from the macrocycle. The structures for all six complexes are supported by1H and13C{1H} NMR spectroscopy, and the compounds1,2, and4are also characterized by single-crystal X-ray crystallography. The1H NMR shows an AA′BB′ splitting pattern for the coordinated macrocycle, and the dispersion between the two sets of multiplets is dependent upon the identity of the macrocycle. The [9]aneN3complexes show only a single reversible (4) or irreversible (3) +3/+2 reduction in the ?1.0 to ?1.4?V range vs. Fc/Fc+. The [9]aneS3complexes show the same reversible (1) or quasi-reversible (2) reduction in the ?0.6 to ?0.9?V range vs. Fc/Fc+as well as a quasi-reversible (1) or irreversible (2) +2/+1 reduction in the ?1.5 to ?1.8?V range vs. Fc/Fc+.