Methanolysis of 7,7,8,8-Tetracyanoquinodimethane: A Consequence of an Initial Charge Transfer Complexation

Abstract

7,7,8,8-Tetracyanoquinodimethane (TCNQ) has several π-bonds and four nitrogen atoms having four unshared electron pairs. This unique structure enhances TCNQ to perform intramolecular charge transfer (CT) transitions within its molecular moiety and/or intermolecular CT interactions with different species having electron-donor properties. The electron affinity 1 of TCNQ is 2.8 eV which permits it to be one of the well known π-acceptors. 2-4 In addition, TCNQbased charge transfer salts are well known too. 5,6 Thus, through the interaction of TCNQ with electron donors it should be considered the simultaneous competing transitions between the intra-transitions (within TCNQ molecule) and the inter-transitions form the donors toward TCNQ. On the other hand, due to the unshared electron pairs on the oxygen atom, MeOH has been used as n-donor in several CT interactions. 2,7-9 Thus, the thing is, on considering a CT interaction between an electron donor and TCNQ (as an electron acceptor) in the presence of MeOH as a medium (solvent) for this interaction, an additional factor should be considered too: the probable occurrence of an addition reaction of MeOH molecule to TCNQ molecule in a nucleophilic attack (as a result of a probable MeOH/TCNQ CT interaction) in competition with the main electron donor/ TCNQ CT interaction. In turn, it is worthwhile to investigate the absorption spectral behavior of the sole MeOH/TCNQ interaction especially from the kinetic standpoint of view. For this purpose this piece of work has been devoted. Experimental Section