Photochemical decarboxylation and deacetylation of the cobalt(III) aminocarboxylate complexes: The crystal structure of the [Co(CH2CH2CH2NH2)(En)2)]Br2 and [Co(Bipy)(Cl)(Edma)]Cl · 2H2O photoproducts (En is Ethylenediamine, Bipy is 2,2′-bipyridine, and Edma is ethylenediaminemonoacetate)

Abstract

The crystals of [Co(CH2CH2CH2NH2)(En)2]Br2 (I) and [Co(Bipy)(Cl)(Edma)]Cl · 2H2O (IIa) (IIa) are studied by X-ray diffraction analysis. Compound I is synthesized by the crystallization of the [Co(En)2(Amb)]2+ primary photolysis products. Compound IIa is synthesized from the [Co(Bipy)(Edda)]+ final photolysis products (En is ethylenediamine; Bipy is 2,2′-bipyridine; Edma and Edda are the anions of ethylenediaminemonoacetic and ethylenediamine-N,N′-diacetic acids, respectively; Amb is the 4-aminobutyrate ion). The crystal structure of complex I indicates the contraction of the seven-membered aminobutyrate CoO2CCH2CH2CH2NH2 ring to the five-membered CoCH2CH2CH2NH2 ring by the photoelimination of the CO2 molecule. The formation of the Co(III) complexes with the Edma ligands upon the photolysis of [Co(Bipy)(Edda)]+ is due to successive reactions of contraction of the five-membered aminoacetate rings and hydrolysis of the Co-C bond.