A Kinetic Isotope Effect in the Formation of Lanthanide Phosphate Nanocrystals

Studies of kinetic isotope effects in various reactions have been useful for elucidating reaction mechanisms, and it is believed that the same may apply for crystal formation kinetics. We present a kinetic study of the formation of europium-doped terbium phosphate nanocrystals under acidic conditions, including a strong H/D isotope effect. The nanocrystal growth process could be quantitatively followed through monitoring of the europium luminescence intensity, combined with ³¹P NMR kinetics measurements. Such lanthanide-based nanocrystals may serve as an excellent model system for further studying and gaining a deeper understanding of crystal nucleation and growth processes. We conclude that the observed delayed nucleation occurs due to initial formation of pre-nucleation clusters or polymers of the lanthanide and phosphate ions, which undergo a phase transformation to crystal nuclei and further grow by cluster attachment.<br/><br/>https://pubs.acs.org/articlesonrequest/AOR-YDYQEM32KMCHKRAQSJWS