Avance avii 500 nmr spectrometer

Static ³¹P NMR spectra were acquired using Bruker Avance AVII 500 NMR spectrometer (11.7 T) with a CP/MAS probe. An acquisition time and recycle delay of 0.05 s and 5 s, respectively, were used, together with ¹H decoupling. A total of 18,000 spectra were acquired using a spectral width of 200 ppm. The ³¹P NMR experiments were performed at 37 °C.

The PTssNMR method is a set of three different experiments performed on the same sample in a sequential order: DP (direct polarization), CP (cross-polarization), and INEPT (insensitive nuclei enhanced by polarization transfer). PTssNMR experiments were carried out on a Bruker Avance AVII 500 NMR spectrometer. The instrument was equipped with a Bruker E-free 4 mm magic angle spinning (MAS) probe, operated at 5 kHz frequency, and with ¹H and ¹³C resonance frequencies of 500 and 125 MHz, respectively. The temperature was set to 37 °C and calibrated using methanol. A spectral width of 250 ppm was used and the number of scans per experiment was 2048, with the acquisition time and recycle delay being 0.05 s and 5 s, respectively. This gives a total estimated time of ~9 h for all three experiments. All the PTssNMR experiments were performed in duplicate for samples with different total concentrations. The methylene signal of solid α-glycine at 43.67 ppm was used to calibrate the ¹³C chemical shift scale. Data processing was done using a line broadening of 20 Hz, zero filling from 1597 to 8192 time domain points, Fourier transformation, phase correction, and baseline correction by using an in-house Matlab code partially derived from matNMR.

PTssNMR is a combination of three different experiments that are performed on the same sample in a sequential manner, i.e., direct polarization (DP), cross polarization (CP), and insensitive nuclei enhanced by polarization transfer (INEPT) [63 (link),64 (link)]. The experiments were carried out on a Bruker Avance AVII 500 NMR spectrometer equipped with a 4 mm CP/magic angle spinning (MAS) probe, operated at 5 kHz frequency, with ¹H and ¹³C resonance frequencies of 500 and 125 MHz, respectively. The temperature calibration was performed with methanol and set to 32 °C in all experiments [65 (link)]. A spectral width of 250 parts per million (ppm) was used and the number of scans per experiment was 2048 with an acquisition time and a recycle delay of 0.05 and 5 s, respectively. This gave a total estimated time of approximately 9 h for all 3 experiments. Data processing was done using a line broadening of 20 Hz, zero filling from 1597 to 8192 time domain points, Fourier transformation, phase correction, and baseline correction using an in-house Matlab code partially derived from matNMR [66 (link),67 (link)].