Pyridinium hydrobromide perbromide as a brominating agent for the bromination of metal(II) complexes of Schiff base derived from acetylacetone and p-anisidine

Abstract

Pyridinium hydrobromide perbromide (PyHBr 3 ) is used as a brominating agent for the bromination of the Schiff base chelates of copper(II), nickel(II), cobalt(II) and zinc(II) derived from acetylacetone and p-anisidine under acidic and ammoniacal conditions at room temperature. Under ammoniacal condition these complexes [M(H-acpa) 2 where M = Cu I I , Ni I I , Co I I and Zn I I ; H-acpa = Schiff base derived from acetylacetone and p-anisidine] undergo easy γ-bromination to give electrophilic bromoproduct, M(Br-acpa) 2 but in acidic medium they undergo chelate ring cleavage to give [MBr 4 ][PyH] 2 . The structure of these complexes has been characterised by microanalytical data, IR, UV-Vis and 1 H NMR data.