Conducting Langmuir-Blodgett films of hexadecyl-BEDT-TTF charger-transfer salts with inorganic compounds

The first two decades of a versatile electron acceptor building block: 11,11,12,12-tetracyano-9,10-anthraquinodimethane (TCAQ)

“…A different strategy to achieve electrical conductivity involves the use of Langmuir-Blodgett films. 21,[60][61][62][63][64][65] Conducting Langmuir-Blodgett films with high quality morphology and with reproducible and stable properties are interesting in view of the development of molecular electronics. It was shown that the use of surfactant TCNQ derivatives with long-chain alkylic substituents could be successfully used for the preparation of conducting films when used in combination with tetrathiafulvalene derivatives.…”

On the degradation of conducting Langmuir-Blodgett films

“…An appropriate amount (100-120 gl) of this solution was spread onto a water subphase containing an inorganic compound (FeC13) (Analytical Carlo Erba) at a concentration of 10 -4 M, which is necessary for having an acceptor in the film [15]; the water was purified with a Milli-Q system (resistivity 18.2 MQ cm).…”

“…2 could be related to possible redox reactions of the iron added into the film during preparation. Iron present in the LB film plays an acceptor role in the conductive phenomenon [15]. If this iron is reduced by the oxygen present in the air then the loss of pathways for the electrical current should result in a decrease in conductivity; if the loss of pathways corresponds to the discontinuity of the film, then the current should become tunnelling-like.…”

“…The structural organization of LB films was studied by electron diffraction and electron microscopy and probable molecular packing was proposed [11]; the close packing of these molecules in the films was also observed by scanning tunnelling microscopy [12] and the influence of structural changes on the conductivity was explained [13]. The role of the dopant (surfactant acceptor) was studied [14] and the possibility of building up new architectures with organic compounds was investigated [15].…”

Thin film of bis(ethylenedithio)-tetrathiafulvalene radical salt with Dawson polyoxometalate

“…An extend research aspect in last ten years for these hybrid systems is to prepare crystalline phases of tetrathiafulvalene (TTF) family radical salts, i.e. charge-transfer salts (CT) Triki et al, 1991Triki et al, , 1993Gómez-García et al, 1994Davidson et al, 1989; The main techniques used for the preparation of thin film of charge-transfer salts are Langmuir-Blodgett (Li et al, 2001;Berzina et al, 1993;Kawabata et al, 1990;Troitsky et al, 1992), high vacuum evaporation (Molas et al, 2000;Moldenhauer et al, 1995;Deutsch et al, 1999), reticulate polymer matrix approach, and electrochemical process (Wang et al, 2002). The reported thin films are, however, based largely on the system from ET with highly volatile halogen constituents such as ET/I 2 , while that based on other systems are relatively rare (Wang et al, 2002;Ulanski et al, 1998;Tracz et al, 1997).…”