ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
2, 5 -bis-methylthio - 7 , 7', 8, 8' - tetracyanoquinodimethane (BMT-TCNQ), a strong π-electron acceptor, has been newly synthesized and its optical and electrical properties have been investigated in evaporated films. A large bathochromic shift of the visible absorption band (474–590 nm) has been observed in going from solution to the solid state. This is attributed to enhanced electron delocalization in the solid state through close intermolecular S-N contacts (3.2 A(ring)) between the S atom of the -SCH3 group of one BMT-TCNQ molecule and the N atom of the -C≡N group of the neighboring molecule. Evaporated BMT-TCNQ exhibits a high electrical conductivity of 2×10−5 S cm−1 at room temperature as well as a high spin concentration of 2×1017 spins/cm3. The origin of the charge carriers is presumably ascribed to electron-donating impurities which cause the ESR signals, whereas the close intermolecular S-N contacts considerably facilitate the carrier hopping throughout the crystal.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.357701
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