Langmuir-Blodgett films of bis-tetrathiafulvalene substituted macrocycle and TCNQ derivatives

Tetracyanoquinodimethane (TCNQ) derivatives, 2-fluoroTCNQ (F ₁TCNQ), 2,5-difluoroTCNQ (F₂TCNQ) and 2,5-dichloroTCNQ (Cl₂TCNQ) were applied to form molecular nanowire structures of charge transfer complex with dialkyl derivative of bis-tetrathiafulvalene substituted macrocycle (1). When we used Cl₂TCNQ, nanowire network structure was obtained as in the case of tetrafluoroTCNQ (F₄TCNQ) previously reported. Although the nanowires were shorter compared with those of F₄TCNQ complex and formed bundles, they oriented in specific directions recognizing the ionic array on mica surface. In the case of F ₁TCNQ and F₂TCNQ, we obtained nanowire structures almost identical with those of pure 1. The Cl₂TCNQ formed an ionic complex with 1, in which donor units and Cl₂TCNQ were in fully charge-transferred state. Reflecting the electronic structure, the conductivity of nanowires was estimated to be 2×10^-4 S cm^-1.