The synthesis and physical studies of tetracyanoquinodimethane and tetrafluorotetracyanoquinodimethane based anion radical salts and methyl -substituted tetrathiotetracene and tetraselenotetracene based cation radical salts.

摘要

Semiconducting and metal-like organic materials hold considerable importance and promise as the materials for the innovative electrical devices and components for the future because of their unique physical properties.;Other organic semiconductors based on the charge-transfer complexes of methyl substituted benzidines with 7,7,8,8-tetracyanoquinodimethane (TCNQ) and TCNOF;The organic donor molecule, 2,3-dimethyl-5,6,11,12-tetrathiotetracene (DMTTT), was synthesized as a possible precursor for a new series of synthetic metals. The physical properties of both neutral DMTTT and the DMTTT cation radical show very close resemblance to their unsubstituted precursor, 5,6,11,12-tetrathiotetracene (TTT). DMTTT exhibits enhanced solubility and donor character over TTT. The X-ray crystal structure of DMTTT crystallized from monochlorobenzene reveals the planar molecule, DMTTT, stacked in pancake fashion. The orientation of the methyl groups of DMTTT alternate such that there is a local center of inversion symmetry between adjacent pairs of DMTTT molecules.;A Varian ESR spectrometer has been interfaced with a microcomputer via an A/D converter board. The interface operates in the dual channel mode. Therefore, sample and reference spectra from a dual cavity are simultaneously recorded. Software is being developed to analyze both spectra to obtain ESR spectral information. The Fast Fourier Transform (FFT) technique is applied to eliminate noise from the ESR spectra.;A series of organic semiconductors based on 1:1 salts of alkali-metals and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (TCNQF