Effects of solution-phase ordering on the spectroscopic properties and electrooxidative reactivity of isomeric mixtures and isolated isomers of synthesized amidine derivatives

Abstract We present the synthesis of amidine derivatives and the separation of their isomers obtained after the reaction of different bis(phthalic anhydrides) with 1,8-diaminenaphtalene (1,8DAN). The isolated isomers of 4′-(4,4′-isopropylidenediphenoxy)bis(phthalic anhydride) (BPADA) significantly differed in their optical and electrochemical properties, showing distinct changes in reactivity due to electrooxidation. The calculated HOMO energy and visualization of this orbital indicated its localization on the perimidine unit. Thus, the condensation of BPADA with 2,3-diaminonaphthalene was also performed to obtain the naphtho[2,3-d]imidazole units as terminal groups to compare its oxidative reactivity versus the perimidine segment. It was confirmed that only the perimidine-containing compounds were reactive due to electrochemical oxidation; however, in a solution containing a mixture of isomers, we only obtained soluble products. In turn, the isolation of isomers and electrooxidation in a solution containing only one type of isomer resulted in the production of a solid and redox-active product.