Studies on some reactions of cyclopalladated azobenzenes with N,O-chelators

The synthesis and characterization of new planar mixed chelates of the type [Pd(A)(N,O)] (A = orthometallated azobenzene or its substituted derivatives, A(1) to A(5), N,O = 2-picolinato (pic), quinaldato (qnd), 8-quinolinolato (q) and 2-methyl-5-sulphonic-8-quinolinolata (msq)) are achieved by splitting the halogeno-bridge in [Pd-2(A)(2)Cl-2] by aqueous AgNO3 solution followed by the addition of N,O-chelator. [Pd(A(2))(N,O)] occurs as isomer [Pd(A(3))(N,O)] and the composition have been established using H-1 NMR data. The complex composition is supported by elemental analyses and IR data. Cyclic voltammetric studies suggest two successive redox responses correspond to azo reduction. (C) 1998 Elsevier Science Ltd. All rights reserved.