Cyclopalladation of 1,1′-azonaphthalene (= di(naphthalen-1-yl)diazene):: Isolation and characterization of two isomeric complexes

The cyclopalladation of 1,1'-azonaphthalene (= di(naphthalen-1-yl)diazene; 2) with bis(hexafluoroacetylacetonato)palladium(II) (3; [Pd(hfa)(2)]) yields the ortho-palladated complex (1,1,1,5,5,5-hexafluoropentane-2,4-dionato-kappa(2)O,O')[1-(naphthalen-1-ylazo-kappa N-2)naphthalen-2-yl-kappa C-2]palladium(II) (4) as well as the peri-palladated complex (1,1,1,5,5,5-hexafluoropentane-2,4-dionato-kappa(2)O,O')[8-(naphthalen-1-ylazo-kappa N-2)naphthalen-1-yl-kappa C-1]-palladium(II) (5); their structures were corroborated by X-ray analyses. The formation of the novel peri-metallated product 5 containing a six-membered palladacycle strongly depends upon the reaction conditions.