Charge‐transfer complexes of poly(N‐vinylcarbazole) with organic electron acceptors

Abstract

AbstractPoly(N‐vinylcarbazole) and its monomeric analog, i.e., N‐ethylcarbazole, act as donors in charge‐transfer complex formations with such electron acceptors as 2,3,5,6‐tetracyano‐1,4‐dimethylene‐2,5‐cyclohexadien‐1,4‐diylidene, tetracyanoethylene and 2,4,5,7‐tetranitro‐9‐fluorenone. The formation constants of the charge‐transfer complex of N‐ethylcarbazole with the electron acceptors are higher than those of poly(N‐vinylcarbazole) with the same electron acceptors. In order to clarify the polymer effect on these formation constants, poly(N‐vinyl carbazole)s, prepared by two types of polymerizations, are fractionated using a gel permeation chromatography technique, and the fractionated polymers are used for the measurements of the formation constants of the charge‐transfer complexes with various sorts of electron acceptors. The relation between charge‐transfer complex formation and molecular weight of the polymer is discussed in terms of the formation constant and the thermodynamic parameters.