Imidazoles imidazolato complexes

Imidazoles act as monodentate donors for palladium, forming complexes [PdC LJ and [PdLJCfe.216"221 Both cis and trans isomers of the former complexes have been isolated and their antitumour properties investigated.216 A polymeric compound [Pd(imidazolato)2] has also been isolated which contains bidentate bridging imidazolato ligands. 

Condensatfon of 57 with trans-urocanic acid chloride (62) furnished the chelated porphyrin In this case the imidazole was attached at the C-4 rather than the more common N-1 position to allow deprotonation to the imidazolate. After iron insertion and deprotonation addition of Cu(acac)2 yielded the p-imidazolato binuclear complex 64 (Scheme 24), a potential model for the [Cu5 /Cyta ] center of cytochrome oxidase. 

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