The bulk reflectivity and absorption (using alkali halide matrices and thin film dispersions) of polycrystalline K+TCNQ- in the wavelength range between 30 and 4000 cm-1 have been examined in detail. The sharp reflectivity peaks have been analyzed using a classical oscillator fitting procedure to give the peak and oscillator parameters. Most of the observed infrared peaks have been assigned to the fundamental modes of TCNQ- and lattice vibrations. The temperature dependence of the CN stretching peaks in particular have been studied in the 300-433°K temperature range. The reversible and gradual disappearance of one set of CN stretching peaks in K+TCNQ- has been tentatively linked to a possible cell halving phase transition at Tc∼379°K. The results are compared with the spectrum of Rb+TCNQ- which is isomorphous with the postulated high temperature phase of K +TCNQ-.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry