Crystallographic characterization of ethylammonium salts of tetracyanopyridine (TCPy) and fluorescence determination of the degree of substitution of the amino nitrogen atom thereof.

Four new salts of the 3,4-dicyano-2-(dicyanomethylene)-5-methyl-6-phenyl-2H-pyridin-1-ide anion (TCPy−) with mono-, di-, tri- and tetraethylammonium cations were synthesized and structurally characterized by the single-crystal X-ray diffraction method. Solid state photoluminescence characteristics of the prepared salts were studied. Crystallographic features of the crystal packing which are responsible for the position of an emission band were characterized. A novel method of fluorescence determination of gaseous amines using TCPy was developed. [ABSTRACT FROM AUTHOR]