autocatalytic reaction (dimer model): A second clue supporting dimer catalysts came from considering the stochastic ratio of homochiral to heterochiral dimers that is predicted to be formed in a racemic mixture, which is RR:SS:SR = 1:1:2., or homochiral:heterochiral = 1:1. This prediction was validated by NMR spectroscopic studies of such a racemic mixture (Figure ), which showed two diastereomeric species of ca. equal concentrations (1:1.08), with one peak ascribed to the sum of enantiomers (RR+SS = 1+1) and one for SR = 2.