Radical Ion Salts and Complexes, Part XVII. TCNQ Salts of 1,4-Dimethylpyridine and 2,3-Bis(1-methyl-4-pyridinio)butane

Abstract

X-Ray structure determination of the complex salts [MeNC₅H₄Me]⁺[TCNQ₂]^– [1,4–dimethylpyridinium 2(7,7,8,8-tetracyanoquinodimethane) (1–); I] and [Me(NC₅H₄)(Me)CH–CH(Me)(C₅H₄N)Me]²⁺[TCNQ₄]^2– [meso-2,3- bis(N-methyl-4-pyridyl)butane(2+) 4(7,7,8,8-tetracyanoquinodimethane) (2–); II], where TCNQ=(CN)₂C(C₆H₄)C(CN)₂, shows that, although in both salts the TCNQ moieties are stacked in columns, lateral shifts break these columns into diads for I and tetrads for II causing their electrical conductivities to be only moderate (σ=2–4×10^–3 ohm^–1 cm^–1).