Conformational inversion of 2,2′-bipyridine 1,1′-dioxide chelate ring in a series of (2,2′,2′′-triaminotriethylamine)(4,4′-disubstituted-2,2′-bipyridine 1,1′-dioxide)cobalt(III) complexes

✍ Scribed by Hideaki Kanno; Mitsutoshi Yamada; Kazuya Nakata; Maiko Nishimura

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 108 KB
• Volume: 318
• Category: Article
• ISSN: 0020-1693
• DOI: 10.1016/s0020-1693(01)00408-x

✦ Synopsis

A new series of cobalt(III) complexes, [Co(2,2%,2%%-triaminotriethylamine)(4,4%-X 2 bpdo)] 3 + (X =Me, MeO, EtO), where 4,4%-X 2 bpdo denotes 4,4%-disubstituted-2,2%-bipyridine 1,1%-dioxide, were prepared. The complexes were resolved into a pair of enantiomers (conformational optical isomers), and gradually racemized in water by conformational inversion of the skewed 4,4%-X 2 bpdo chelate ring, d X l. The rate of racemization is remarkably reduced with an increase in the electron-releasing ability of the 4,4%-X 2 substituents on bpdo.