A. Kral et H. Laatsch, 4,4'-BINAPHTHYLIDENE-1,1'-DIONES - COLOR AND STRUCTURE, Zeitschrift fur Naturforschung. B, A journal of chemical sciences, 48(10), 1993, pp. 1401-1407
Synthesis and properties of various 4,4'-binaphthylidene-1,1'-diones a
re described. The UV spectra of the deep red to purple diones may be c
alculated on the base of substituent increments. The experimental valu
es of the analyzed substituents can be reproduced using PPP calculatio
ns with satisfying accuracy, which makes it possible to predict also a
bsorption maxima of hitherto unknown 4,4'-binaphthylidene-1,1'-diones.