Sensitivity considerations in polarization transfer and filtering using dipole-dipole couplings: implications for biomineral systems.

摘要: Abstract The robustness and sensitivities of different polarization-transfer methods that exploit heteronuclear dipole–dipole couplings are compared for a series heterogeneous solid systems, including polycrystalline tetrakis(trimethylsilyl)silane (TKS), adamantane, physical mixture doubly 13C,15N-enriched singly 13C-enriched glycine, powder sample siliceous marine diatoms, Thalossiosira pseudonana. were analyzed according to their respective frequency-matching spectra or resultant signal intensities. For 13C{1H} cross-polarization experiments, adiabatic passage Hartmann–Hahn (APHH-CP) was shown have several advantages over other methods, (HHCP), variable-amplitude (VACP), ramped-amplitude (RACP). X–Y such as 13C{15N}, high comparable obtained by using APHH-CP with Lee–Goldburg decoupling the transferred-echo double resonance (TEDOR) experiment. findings applied multinuclear 1H, 13C, 15N, 29Si CP MAS characterization diatom sample, challenging inorganic–organic hybrid places demands on NMR sensitivity.