PREPARATION OF A TRIPHENYLCARBINOL MOIETY-CONTAINING CELLULOSE DERIVATIVE AND ITS PROPERTIES

A triphenylcarbinol (TPC) moiety-containing cellulose derivative (TPC-Cell) was prepared by a two-step reaction. First, microcrystalline cellulose was dissolved in SO2-diethyl-amine-dimethyl sulfoxide and homogeneously reacted with p-bromobenzyl bromide to obtain tri-O-(p-bromobenzyl)cellulose (BE-Cell). Second, the BB-Cell was reacted with butyllithium and then with Michler's ketone. The degree of substitution (DS) of the obtained ethanol-soluble TPC-Cell was up to 0,56. The leuco form of TPC moiety in TPC-Cell showed a small extent of ionic dissociation in ethanol under irradiation with UV light of lambda > 290 nm, accompanied by a large extent of decomposition of the structure. With additions of acid and then of alkali, the TPC structure was reversibly isomerized from the leuco form to the colored form and then from the colored form to the leuco form. However, repeated cycles of the additions of acid and alkali resulted in considerable fatigue with the number of cycles.