The reaction products of N-alkylquinoxalines with 7,7,8,8-tetracyanoquinodimethane

Simple (1:1) and complex (2:3) TCNQ salts of the N-ethylquinoxalinium (NEQ) and N-methylquinoxalinium (NMQ) cations were prepared and characterized. In contradiction to earlier claims it was found that the 1:1 NMQ-TCNQ compound is not highly conducting but is a semiconductor. The triclinic crystals with unit cell dimensions a = 4.79, b = 10.46, c = 7.60 Å, α = 93.49, β = 110.92, γ = 82.69° show triplet exciton lines in the epr spectra indicating the occurrence of dimerized radicals in this solid. The high dc conductivity of the simple salt as reported earlier can only be attributed to a complex salt.