Nature of the lowest energy excited state of a bis-phenanthroline [2]-catenand and its Cu(I), Ag(I) and Co(II) complexes

✍ Scribed by Nicola Armaroli; Michael A.J. Rodgers; Paola Ceroni; Vincenzo Balzani; Christine O. Dietrich-Buchecker; Jean-Marc Kern; Abdelhakim Bailal; Jean-Pierre Sauvage

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 286 KB
• Volume: 241
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(95)00666-r

✦ Synopsis

The excited state absorption and emission spectra and lifetimes of a [2]-catenand made of two interlocked 30-membered rings (containing 2,9-dianisyl-l,10-phenanthroline-type coordinating moieties) and its Co 2÷, Cu +, and Ag ÷ complexes have been investigated in CH2CI 2 solution. The lowest energy excited state is established to be a triplet ligand-centered level for the Ag + complex and a triplet metal-to-ligand charge-transfer level for the Cu + complex. For the Co 2+ complex, where no emission or transient absorption can be observed, the lowest excited state is most likely to be a distorted triplet metal-centered level. No transient absorption can be observed for the lowest energy triplet excited state of the [2]-catenand in CH2C12 solution because of a fast reaction with solvent molecules.