Abstract
Charge-transfer (CT) complex of o-toluidine (o-tol) with the π-acceptor tetrachloro-p-benzoquinone (p-chloranil; CHL) has been synthesized and characterized, along with the products of the elimination reaction of o-toluidine (o-tol) with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and 7,7,8,8-tetracyanoquinodimethane (TCNQ). Their properties and structures have been investigated using electronic absorption and IR spectroscopy as well as elemental analyses of the isolated compounds. The o-tol/p-CHL CT complex is shown to consist of a CHL− radical anion and o-tol+ radical cation. The formations of all three compounds result in the appearance of new UV-Vis spectral bands that peaked in intensity at a stoichiometric ratio of 1:1. 1H-NMR and mass spectra were used to confirm the formation of the o-tol/DDQ and o-tol/TCNQ products. The new 7,8-dicyano-7′,8′-o-toluidilequino-dimethane and 2,3-dichloro-5-cyano-6-o-toluidil-p-benzoquinone products resulted from the rapid reaction of o-tol with TCNQ and DDQ, respectively. Thermogravimetric studies showed that the CT-complex decomposes in three steps whereas the new compounds decompose in a single step. Thermodynamic parameters were computed from the thermal decomposition data.
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Refat, M.S., El-Metwally, N.M. Investigation of charge transfer complexes formed between 3,3′-dimethylbenzidine (o-toluidine) donor and DDQ, p-chloranil and TCNQ as π-acceptors. Chin. Sci. Bull. 56, 1993–2000 (2011). https://doi.org/10.1007/s11434-011-4525-9
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DOI: https://doi.org/10.1007/s11434-011-4525-9