571201-62-2Relevant academic research and scientific papers
Novel 4,4′-bipyridinium-based cationic mono- and bicyclic cyclophanes
Rajakumar, Perumal,Srinivasan, Kannupal
, p. 1277 - 1284 (2003)
The intra-annularly functionalised tetracationic cyclophanes 3a-b were synthesised from the corresponding m-terphenyl dibromides and 4,4′-bipyridine by a simple quaternisation methodology. An intra-annularly linked tetracationic cyclophane 10 was synthesised in three steps and it possesses a concave structure and novel intramolecular CT interactions. Synthesis of the tetracationic cyclophanes 13, 16a and 16b containing carbonyl groups was accomplished from the corresponding carbonyl dibromides and 4,4′-bipyridine. Sixfold coupling of a tricarbonyl tribromide with 4,4′-bipyridine afforded a rare hexacationic cyclophane 18. The cyclophanes 3a and 3c form CT complexes with a bis(1H-indol-3-yl)-(phenyl)methane compound while the cyclophane 13 forms CT complexes with 1,4-dimethoxybenzene and indole. Electrochemical parameters were obtained for all the cyclophanes. They exhibit two sets of redox peaks and most of them are quasireversible. The smallest-cavity cyclophane 13 has the lowest reduction potentials in the series. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
