Mechanistic insights into tautomerism‐induced crystal growth self‐inhibition informed by kinetics modeling

Abstract Mechanistic understanding of tautomer, a new class of modifiers, that affects crystal shape and growth kinetics is crucial to tailoring the property of tautomeric crystalline materials but remains elusive. Herein, we investigated this effect through a combination of kinetics modeling and experimental validation. Accounting for both tautomeric thermodynamics and inter‐conversion kinetics, we developed mechanistic expressions that consider the tautomerism‐induced growth self‐inhibition process. Our approach enables us to calculate the influence of various operational conditions on growth kinetics and to predict the dominant factors of growth self‐inhibition by tautomers. Tautomers were found primarily to suppress crystal growth by reducing the driving force under mass‐transfer growth regime. However, the inhibitory effect shifts to a more complex synergistic action of step pinning and kink blocking mechanisms with interfacial tautomer inter‐conversions under surface‐integration limited growth regime. Finally, the effectiveness of our developed kinetics model was further experimentally validated using two urate salts as model systems.