Electrosynthesized copper polycorroles as versatile materials in double lateral heterojunctions

Abstract

Metallocorrole derivatives are an emerging class of coordination complexes successfully exploited in different applications, ranging from catalysis to medical field, due to their peculiar tunable properties. Herein, new polycorroles materials are in situ synthesized and deposited on the electrodes in a one-step electrochemical method from 5,10,15-(4-aminophenyl)corrolato]copper(III) as monomer, generating phenazine bridges containing polymer chains. Conductive films are obtained and the film thickness can be controlled by tuning the number of potential scans. However, the nature of the resulting polymer is affected by the electropolymerization conditions: in neat CH2Cl2 the protonation of polymer chains occurs. The role of proton scavenger 2,6-lutidine is worth mentioning, which prevents demetallation of corrole macrocycle. The polycorrole films are further combined with lutetium bis-phthalocyanine to realize double lateral heterojunction (DLH) sensors for ammonia detection, in which organic-organic interface plays a key role in their charge transport properties. The protonation of polycorrole can tune the p- or n-nature of the semiconducting film, and the highest sensitivity obtained with these devices favorably competes with these reported so far for DLH heterojunctions, with a limit of detection as low as 125 ppb for NH3.