3,5-Diferrocenylpyridine: Synthesis, characterisation, palladium(II) dichloride complex and electrochemistry

Abstract

3,5-Diferrocenylpyridine was synthesised from 3,5-dibromopyridine and ferroceneboronic acid, in respectable yield (48%), using a microwave-enhanced Suzuki cross-coupling reaction. This novel ligand and its palladium(II) dichloride complex have been fully characterised using elemental analysis, HR-ESI-MS, IR, UV and NMR spectroscopy. Additionally, the molecular structures of 3,5-diferrocenylpyridine and [Pd(3,5-diferrocenylpyridine) 2Cl 2] were confirmed by X-ray crystallography. A comprehensive study of the electrochemistry of 3-ferrocenylpyridine, 3,5-diferrocenylpyridine and their palladium(II) dichloride complexes was performed using traditional hexafluorophosphate and weakly-coordinating fluorinated aryl borate anions. Electronic communication between the two proximal ferrocenyl centres of 3,5-diferrocenylpyridine and its palladium complex is only observed when the weakly-coordinating fluorinated aryl borate anions are used as the supporting electrolyte. © 2012 Elsevier Ltd. All rights reserved.