Sensitive NMR Method Reveals Motions of Surface Sites

PCCP cover and experiment data
The front cover of PCCP displays stylized 1H chemical shift anisotropy measurements that reveals the motions of a Cp2ZrOCH3/SiO2 complex. The experiment yields comparable data as a dipolar measurement (top right) but in a fraction of the time.
Scientific Achievement

A new, high-sensitivity, approach for studying molecular dynamics is reported, enabling the study of surface sites.

Significance and Impact

Molecular motions are thought to have an outsized impact on catalytic activity. A new method leverages 1H chemical shift anisotropy (CSA) to reveal the motions of sparsely populated surface sites and how intersite clustering can impact site accessibility.

Research Details
  • Theoretical investigation reveals that 1H CSA can be used as a sensitive substitute for dipolar-based dynamic methods.
  • The method is applied to study the motions of supported organic, Zn, and Zr species.
  • Comparisons with MD simulations suggest that the motions of catalytic sites may be impeded by intersite proximities.

Southern, S. A.; Liu, D.-J.; Chatterjee, P.; Li, Y.; Perras, F. A. Phys. Chem. Chem. Phys. 2023, 25, 5348-5360. DOI: https://doi.org/10.1039/D2CP04406D