Solid-state NMR spectra were recorded on a Bruker
Avance II spectrometer (Bruker Biospin, Faellanden, CH) operating
at 700 MHz 1H Larmor frequency (16.4 T), corresponding
to 146 MHz 13C Larmor frequency. The spectrometer is equipped
with a 3.2 BVT MAS probehead in double-resonance mode. The spinning
rate was regulated to 11111 ± 2 Hz using dry air, and the temperature
was set to 280 K. The pulse lengths were 2.5 and 3.5 μs for 1H and 13C, respectively. Cross-polarization20 (link) was achieved by matching the k = 1 Hartmann–Hahn condition.21 (link) For the {1H}13C HETCOR spectra, the spectral
windows for the different nuclei were 60 and 315 ppm for 1H and 13C, respectively. During the 1H magnetization
evolution under the chemical shift in the indirect dimension of heteronuclear
correlation experiments, a PMLG decoupling sequence was used to suppress 1H–1H dipolar couplings.22 (link),23 (link) The CP spectrum was denoised through the MCR procedure.24 (link),25 (link)
Avance II spectrometer (Bruker Biospin, Faellanden, CH) operating
at 700 MHz 1H Larmor frequency (16.4 T), corresponding
to 146 MHz 13C Larmor frequency. The spectrometer is equipped
with a 3.2 BVT MAS probehead in double-resonance mode. The spinning
rate was regulated to 11111 ± 2 Hz using dry air, and the temperature
was set to 280 K. The pulse lengths were 2.5 and 3.5 μs for 1H and 13C, respectively. Cross-polarization20 (link) was achieved by matching the k = 1 Hartmann–Hahn condition.21 (link) For the {1H}13C HETCOR spectra, the spectral
windows for the different nuclei were 60 and 315 ppm for 1H and 13C, respectively. During the 1H magnetization
evolution under the chemical shift in the indirect dimension of heteronuclear
correlation experiments, a PMLG decoupling sequence was used to suppress 1H–1H dipolar couplings.22 (link),23 (link) The CP spectrum was denoised through the MCR procedure.24 (link),25 (link)
