On the heat of formation of n—π or π—n types of charge transfer complexes

Thermochemistry of some π-π charge transfer complexes formed between methylbenzene donors and π-electron acceptors

“…For those complexes for which there are no experimental data, theoretical AHf should replace the speculative guesswork often presented in the literature, especially for n-rr* CT complexes, where the magnitude of AHy is of the order of 4-17 kJ/mol [1] and hence the uncertainty in the experimental data is higher. Therefore, as a continuation of our studies on the thermochemistry of molecular complexes [2][3][4][5][6][7][8][9][10] in relation to AHr, we have examined the rr-n* CT complexes formed between methylbenzene donors and three acceptors, viz. pyromellitic dianhydride (PMDA), 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and 2,3-dicyano-pbenzoquinone (DCNQ).…”