As a supercooled melt at 150 degrees C, the chiral compound 1,1'-binaphthyl
racemizes rapidly. The melt solidifies as a conglomerate of crystals, each
consisting exclusively of either R-(-)- or S-(+)-enantiomer. We find that
crystallization performed with a 2.00 g sample with constant stirring produ
ces a large enantiomeric excess (mean 77%) in almost every crystallization,
The predominance of R-(-) or S-(+) was random. Unstirred 2.00 g samples of
binaphthyl produce a much lower enantiomeric excess (mean 20%) with optica
l activity centered around zero similar to an earlier report.(1) Thus, chir
al symmetry breaking can be realized in crystallization from a melt by the
mere act of stirring, as it can be in crystallization from a solution.