Kinetics of 1H →31P NMR cross-polarization and dynamics in a layered crystalline α-Sn(IV) phosphate

Vladimir I Bakhmutov; Douglas W Elliott; Hong-Cai Zhou

doi:10.1016/j.ssnmr.2023.101898

Kinetics of ¹H →³¹P NMR cross-polarization and dynamics in a layered crystalline α-Sn(IV) phosphate

Solid State Nucl Magn Reson. 2023 Oct:127:101898. doi: 10.1016/j.ssnmr.2023.101898. Epub 2023 Aug 23.

Authors

Vladimir I Bakhmutov¹, Douglas W Elliott², Hong-Cai Zhou²

Affiliations

¹ Department of Chemistry, Texas A&M University, College Station, TX, 77843, United States. Electronic address: [email protected].
² Department of Chemistry, Texas A&M University, College Station, TX, 77843, United States.

PMID: 37639882
DOI: 10.1016/j.ssnmr.2023.101898

Abstract

The proton-phosphorus (H-P) cross-polarization (CP) is effective in Sn(HPO₄)₂·H₂O despite of the presence of paramagnetic ion impurities. Polarization constants T_H-P and ¹H T_1ρ times are measured in static Sn(HPO₄)₂·H₂O by the kinetic variable-temperature H-P CP experiments. The temperature dependence of the ¹H T_1ρ times is interpreted in terms of proton movements in the interlayer space occurring between the phosphate groups without participation of the water molecules. The process requires an activation energy of 8.7 ± 0.7 kcal/mol. The MAS effect on the ¹H T_1ρ times is shown and discussed.

Keywords: Cross-polarization; Dynamics; Solid-state NMR; T(1ρ) relaxation times.