Self-Induced Odd-Even Effect in Enzyme-Catalyzed Reactions

Enzyme-catalyzed reactions often take place in water. In this work, ionic liquids (ILs) were added to water to shift the
reaction equilibrium of enzyme-catalyzed reactions with the goal to increase the reaction yield of the product methylated
1-phenylethanol (Me-PE). Tetrahydrothiophene-based ILs (THT-ILs) were used with varying IL-cation chain length and
constant IL-anion. An odd–even effect of the IL-cation chain length on the yield was discovered. Beneficially, the addition
of small amounts of THT-ILs with odd numbered chain length allowed very high yields, while adding THT-ILs with even
numbered chain length caused lower yields. Reasoning behind this odd-even effect was found in molecular interactions
of the IL cation and the reaction product Me-PE and, further, critical micellar concentration measurements validated the
observations.