Liquid− and solid−state study of charge-transfer (CT) interaction between drug triamterene as a donor and tetracyanoethylene (TCNE) as an acceptor

Abstract

In this work, the liquid–liquid and solid–solid charge-transfer (CT) interactions of drug triamterene (TA) with tetracyanoethylene (TCNE) were reported. The soluble TA-TCNE CT complex was easily generated by mixing acetonitrile solution of TA as the donor and TCNE as the acceptor at room temperature. The solid TA-TCNE CT complex was easily generated by grinding equimolar amounts of TA and TCNE in powder form without any solvent. The results confirmed that the donor interacted with the acceptor via a strong, liquid-state or solid-state reaction generating a CT complex linked by an n → π* transition. The TEM results showed that the CT complex was composed of mixed spherical, oval, and elliptical particles with a mean diameter of ~15 nm. The solid–solid approach proved to be a highly efficient, time- and cost-effective, eco-friendly, and straight-forward means of forming a CT complex with excellent yield (96%).