Novel 4,4′‐Bipyridinium‐Based Cationic Mono‐ and Bicyclic Cyclophanes

Abstract

The intra-annularly functionalised tetracationic cyclophanes 3a−b were synthesised from the corresponding m-terphenyl dibromides and 4,4Ј-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 4,4Ј-bipyridine. Sixfold coupling of a tricarbonyl tribromide with 4,4Ј-bipyridine af-

cyclo-Bis(paraquat-m-terphenylene) tetrakis(hexafluorophosphate) tetrahydrate

“…The title compound was synthesized by re¯uxing an equimolar mixture of m-terphenyldibromide (Hart & Rajakumar, 1995) and 4,4 H -bipyridine in acetonitrile for 48 h, followed by column chromatography and counter-ion exchange with NH 4 PF 6 (Rajakumar & Srinivasan, 2002). Single crystals, suitable for X-ray studies, were grown by vapour diffusion of diisopropyl ether into a solution of (I) in acetonitrile.…”

Two Copper(II) Complexes Built from a Novel Redox‐Active Bipyridinium Dimer Ligand and Oxalate Anions: Synthesis, Crystal Structure and Magnetic Properties

“…Currently, not many bridging ligands with electrochemical and photochemical properties are available. Bipyridinium dimers, as derivatives of the viologens, exhibit photoelectrochemical activity and a change of spin multiplicity upon external stimulus 18−20. Their terminal N‐donor atoms and π‐conjugated system can provide various coordination modes and structural motifs, which enable construction of versatile molecular assemblies and incorporation of optical, electronic and magnetic properties.…”

Self-complementary azolophanes

“…The use of m-terphenyl spacer may also improve the yield of the cyclophanes without the use of any templates. 20 With this in mind, each of the precyclophanes 2-4 was heated with 1 equivalent of m-terphenyl dibromide 5, in acetonitrile at reflux under high dilution conditions for 5 days to afford the self-complementary azolophanes 6-8 as white solids in 23, 39 and 31 %, respectively, after purification (Scheme 2). * Correspondent.…”