DNP-Enhanced Ultrawideline Solid-State NMR Spectroscopy: Studies of Platinum in Metal-Organic Frameworks.
Ultrawideline dynamic nuclear polarization (DNP)-enhanced (195)Pt solid-state NMR (SSNMR) spectroscopy and theoretical calculations are used to determine the coordination of atomic Pt species supported within the pores of metal-organic frameworks (MOFs). The (195)Pt SSNMR spectra, with breadths reaching 10 000 ppm, were obtained by combining DNP with broadbanded cross-polarization and CPMG acquisition. Although the DNP enhancements in static samples are lower than those typically observed under magic-angle spinning conditions, the presented measurements would be very challenging using the conventional SSNMR methods. The DNP-enhanced ultrawideline NMR spectra served to separate signals from cis- and trans-coordinated atomic Pt(2+) species supported on the UiO-66-NH2 MOF. Additionally, the data revealed a dominance of kinetic effects in the formation of Pt(2+) complexes and the thermodynamic effects in their reduction to nanoparticles. A single cis-coordinated Pt(2+) complex was confirmed in MOF-253.
Ames Laboratory, U.S. Department of Energy , Ames, Iowa 50011, United States.
Takeshi
T
Kobayashi
Ames Laboratory, U.S. Department of Energy , Ames, Iowa 50011, United States.
Frédéric A
FA
Perras
Department of Chemistry, Iowa State University , Ames, Iowa 50011, United States.
Tian Wei
TW
Goh
Department of Chemistry, Iowa State University , Ames, Iowa 50011, United States.
Tanner L
TL
Metz
Ames Laboratory, U.S. Department of Energy , Ames, Iowa 50011, United States.|Department of Chemistry, Iowa State University , Ames, Iowa 50011, United States.
Wenyu
W
Huang
Ames Laboratory, U.S. Department of Energy , Ames, Iowa 50011, United States.|Department of Chemistry, Iowa State University , Ames, Iowa 50011, United States.
Marek
M
Pruski