Coupling of arylamine with coordinated naphthylazoimidazole in palladium(II) complexes. Spectroscopic and electrochemical studies

Department of Chemistry, Inorganic Chemistry Section, Jadavpur University, Kolkata-700 032, India E-mail : c_r_sinha@yahoo.com Fax : 91-033-24137121 Manuscript received 23 April 2007, accepted 25 April 2007 1-Alkyl-2-(naphthyl-α-azo)imidazoles (α-NaiR) are bidcntate N,N'-chelator and form Pd(α-NaiR)Cl2 complexes. The reaction of Pd(α-NaiR)Ci2 (2) with ArN2 in MeCN has synthesized C-N coupled product, Pd(α-NaiR-N-Ar)CI (3-5). The stereochemistry and the bonding are described by 1H NMR data. The solution electronic spectra of the amine coupled products exhibit multiple transition within 600-850 nm which are absent in the precursor complex, Pd(α-NaiR)CI2• Cyclic voltammogram shows azo reductions exhibit four successive 1·edox couples, one of them (positive to SCE) is oxidative in nature and other (negative to SCE) are ligand reductions