SOLID STATE NMR INVESTIGATION OF MOLECULAR DINAMICS BY CP-MAS

Carmen Tripon, Xenia Filip, C. Filip

National Institute for Research and Development of Isotopic and Molecular Technologies, P.O. Box 700, RO-400293, Cluj‑Napoca, Romania

Nuclear magnetic resonance (NMR) spectroscopy is a powerful tool for investigating local structure and motion in molecules. Molecular dynamics is an often encountered property and plays an important role in the function of proteins, nucleic acids, synthetic polymers and other macromolecules.
 The combination of the cross polarization (CP) technique with magic angle spinning (MAS) has become one of the most important and commonly performed solid-state nuclear magnetic resonance experiment. A CP-MAS one-dimensional experiment offers high sensitivity spectra of  13C (15N) nuclear spins in solids by polarization transfer from abundant proton spins and by eliminating broadening from chemical shift anisotropy and dipolar coupling. In adition, important structural and dynamical information can be extracted from studying the build-up of the nuclear polarization as function of the CP contact time. Here we investigate the potential of CP and Lee-Goldburg cross polarization (LG-CP) techniques for characterizing molecular motion in organic systems.