New podands with terminal chromogenic moieties derived from formazans

Abstract

Synthesis of several new podands, bearing various terminal chromophoric functions of formazan (9–11), verdazyl (18–20) and verdazylium salt (21–23) types and having a different length of oligooxyethylene bridge between chromophoric units, is developed. Calculated (Alchemy-2000) and found (EPR data) distances between spin centers in bis-radicals 18–20 correlate well. Such spin-labeled species could be good models for the EPR study of host–guest interactions involving ethylene glycol-based podands.