Journal article
Investigation of the nature of the unpaired electron states in the organic semiconductor N-methyl-N-ethylmorpholinium-tetracyanoquinodimethane
The nature of the unpaired electron states in the dimerized phase of the crystalline organic semiconductor N-methyl-N-ethylmorpholinium-tetracyanoquinodimethane [MEM(TCNQ)2] is investigated by the combined means of polarized-optical-reflectance measurements and microscopic theoretical analysis. It is found that each unpaired electron is localized on a dimeric TCNQ unit, and it is demonstrated that the two-site molecular orbital (MO) which accommodates the unpaired electron involves internal molecular distortion of the dimeric unit.
Experimental values are deduced for the intradimer π MO hopping integral, the TCNQ monomer ag molecular-vibration frequencies and linear-electron-molecular-vibration coupling constants, and the difference in energy of the slightly nonequivalent TCNQ monomer π MO's. The dimer charge oscillation associated with the extremely weak coupling of the unpaired electron to the high-frequency ag C-H stretch mode of the TCNQ molecule is observed for the first time.
Language: | English |
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Year: | 1980 |
Pages: | 3437-3446 |
ISSN: | 1550235x , 10980121 , 24699950 , 10953795 and 01631829 |
Types: | Journal article |
DOI: | 10.1103/PhysRevB.21.3437 |