Picric acid electron donor-acceptor complexes

Some complications arise from the presence of proton donor-acceptor interactions134 when the donor is a protic amine. The separate evaluation of the two kinds of interactions may be a difficult problem. Similarly, if the electron acceptor is also a proton donor, the overlapping of salification and complexation processes makes the separate investigation of the interactions very difficult. This is the case in the complexes between amines and picric acid or other related phenols. For complexes of 2,4,6-trinitro-3-hydroxypyridine135 and... 

The presence of P-CD favors the formation of a charge-transfer (CT) complex between 2-methoxynaphthalene and o-dicyanobenzene, as demonstrated by the variations in the absorption spectrum. The excitation of the charge-transfer complex caused a structureless emission with maximum at 480 nm. Since methoxynaphthalene and dicyanobenzene do not form CT complexes in water, it was concluded that the complexed methoxynaphthalene and the complexed dicyanobenzene aggregate to form a 2 1 1 complex (CD-methoxynaphthalene-dicyanobenzene) [130]. The y-CD promoted formation of charge-transfer complexes between a- and / -naphthylacetic acid (as donors), picric acid, and four isomeric dinitrobenzoic acids (as electron acceptors) was reported in references 147 and 148. 

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