EPR Spectra of the Genuine-Organic and Metal-Organic TCNQ-Based Anion Radical Salts

We have measured the electron paramagnetic resonance spectra of genuine-organic anion-radical salts $[Me-2,6-di-Me-Py](TCNQ)_{2}$, $[Me-3,5-di-Me-Py](TCNQ)_{2}$, $[N-Me-OH-Me-Py](TCNQ)_{2}$, $[N-Et-OH-Me-Py](TCNQ)_{2}$, and metal-organic anion-radical salt $[Mn-phen_{3}](TCNQ)_{2}$·$H_{2}O$ in the temperature range from 2 K to 300 K in the X-band frequency range. A comparison study of the shape of spectra, g-factors and linewidths with respect to the composition and crystal structure of studied compounds is presented. While the genuine-organic anion-radical salts display a typical EPR response originating from TCNQ pairs, the spectra of metal-organic anion-radical salt are dominated by the contribution of transition metal.