Co(III) complexes of Me-salpn and Me-salbn and the ring size effect on the coordination modes and electrochemical properties: The crystal structures of trans-[CoIII(Me-salpn)(py)2]PF6 and cis-α-[CoIII(Me-salbn)(4-Mepy)2]BPh4·4-Mepy

摘要: The synthesis and characterization of a series cobalt(III) complexes the general type [Co(N2O2)(L-2)](+) are described. N2O2 Schiff base ligands used Me-salpn (H2Me-salpn = N,N'-bis(methylsalicylidene)-1,3-propylenediamine) (1-3) Me-salbn (H2Me-salbn N,N'-bis(methylsalicylidene)-1,4-butylenediamine) (4-5). two ancillary L include: pyridine (py) 1, 3-metheylpyridine (3-Mepy) 2, 1-methylimidazole (1-MeIm) 3, 4-methylpyridine (4-Mepy) 4 5. These have been characterized by elemental analyses, IR, UV-Vis, H-1 NMR spectroscopy. crystal structures trans-[Co-III(Me-salpn)(py)(2)]PF6, cis-alpha-[Co-III(Me-salbn)(4-Mepy)(2)]BPh4 center dot 4-Mepy, 4, determined X-ray diffraction. Examination solution crystalline revealed that outer coordination sphere exerts noticeable influence on inner Co(III) ion. electrochemical reduction these at glassy carbon electrode in acetonitrile indicates first process corresponding to Co-III-Co-II is electrochemically irreversible, which accompanied dissociation axial (R-py)-cobalt bonds. It has also observed state stabilized with increasing flexibility ligand environment. (C) 2007 Elsevier Ltd. All rights reserved.