NOVEL PALLADIUM COMPLEXES OF SE,N,SE TRIDENTATE LIGANDS DERIVED FROM CYCLOALKENO-1,2,3-SELENADIAZOLES

The reaction between [Pd-2(dba)(3)] (dba = dibenzylideneacetone), a tr ialkylphosphine, and a cycloalkeno-1,2,3-selenadiazole in toluene unde r reflux leads in good yield to the complexes [PdL(PR3)] [L = SeC(R-1) =C(R-2)N=NC(R-1)=C(R-2)Se; R-1-R-2 = (CH2)(n);R = Et,Bu-n] containing a novel Se,N,Se tridentate ligand formed by the coupling of two 1,2,3- selenadiazole molecules; the structure of the product with R = Bu-n an d n = 4 has been determined by X-ray crystallography.