Synthetic conductive materials. V. Synthesis and characterization of charge-transfer complex of 3,6-Bis(2′-pyridyl)-4,5-dihydro-1,2,4,5-tetrazine and 7,7,8,8-tetracyanoquinodimethane

Abstract

3,6-Bis(2′-pyridyl)-4,5-dihydro-1,2,4,5-tetrazine (PTAH 2) has been synthesized by 2-cyanopyridine and hydazine. The acetonitrile solution of PTAH 2 and 7,7,8,8-tetracyanoqinodimethane was mixed with 1:1mole ratio and stand for 2 weeks. The black needle crystal has been characterized by elemental analysis, IR, NMR, ESR, MS, UV/VIS/NIR, DSC, CV, magnetic susceptibility and electric conductivity. This charge-transfer complex has (PTAH 2) (TCNQ) composition with segregated stacking. The segregated stacking was evidenced by IR spectra which show very strong absorption before 1000 cm −1 then drop to normal pattern. Many sharp indentations in a very broad electronicabsorption envelope which had a steep edge at 1000 cm −1 caused byvibrations whose absorption falls inside the conduction band were observed in 4000-1000 cm −1 range. All other physical properties characterized by above physical methods will be discussed. The electric conductivity (powder form) is 4.8 × 10 −1Scm −1 at 20°C with activation energy of 0.08 eV. This very low activation energy may be caused by contact resistance between powder particles. The intropsic properties of electric conduction may be metallic type.