15-04

R.R.E. Steendam, J. Dickhout, W.J.P. van Enckevort, H. Meekes, J. Raap, F.P.J.T. Rutjes,

E. Vlieg,

Linear deracemization kinetics during Viedma ripening: autocatalysis overruled by chiral additives,

Cryst. Growth Des. 15 (2015) 1975-1982

Abstract:

Viedma ripening proceeds through an autocatalytic feedback mechanism which exponentially deracemizes an initially racemic solid state to an enantiopure end state. Here we show that, in the presence of enantiopure additives with a concentration of as low as 2.5 × 10^–2 mol %, Viedma ripening proceeds with an overall linear and faster increase in enantiomeric excess. These experimental results can be explained using a simple model which assumes a difference in growth and dissolution rates between the enantiomers. This model also accounts for the generally observed linearity during the initial stages of Viedma ripening without additives