A study on the aryla,. zo coupling reaction of bis-(acetylacetone)ethylenediaminocopper(II) and bis(acetylacetone)ethylenediaminonickei(II)

Department of Chemistry, University College, Thiruvananthapuram-695 034, Kerala, India E-mail : drthanal@rediffmail.com Manuscript received 8 May 2006, revised 17 August 2006, accepted 23 August 2006 The electrophilic substitution of aryl diazonium ion on the cu^ll and Ni^ll chelates of bisacetylacetone) ethylenediamine [H₄enacac] in aqueous medium have been studied. The coupling products were isolated and characterized by elemental analysis,magnetic susceptibility measurement and electronic, infrared,¹H NMR, ESR and mass spectral studies. The parent chelates have undergone coupling at both the acetylacetone wings of the chelated ligand without decomposition.The geometry around the metal ion of the product is square planar as in the parent chelates. However a rearrangement is found occurred in the newly introduced azo group to hydrazone group followed by the coordination of its nitrogen to metal ion leaving the acetyl group free.As a result the coordination environment around the metal ion is changed from N₂O₂ to N₄.