ON THE RESOLUTION OF DIHYDROXYDIPHENYLMETHANES ON ACHIRAL CRYSTALLINE CELLULOSE-II - CORRELATION OF EXPERIMENTAL AND CALCULATED RESULTS

The minimum energy interactions of the conformations of the three isomers of dihydroxydiphenylmethane averaged each over a number of 24 sites on an elementary model of crystalline cellulose II, composed of 20 anhydroglucose residues distributed over five chains, were calculated by a constrained and a non-constrained force field molecular mechanics method. The percentage differences in the averaged minimum energies were found to correspond to the percentage differences in paper chromatography Rf values of the three dihydroxydiphenylmethane isomers. Of interest was the apparent correspondence of the two sets of results independently of the polarity of the solvent employed, indicating the example chosen might be one of the simpler cases possible. Although the number of sites used must be considered a physical approximation, it appeared to already give sufficient correspondence between numerical and experimental results. The indications from the obtained correspondence of results appear to be that separation of non-enantiomeric isomers on achiral cellulose substrates could also be modelled by computational methods.