4. Acquisition

Time requirement: 10 min Sample: Fill a solid-state rotor with finely powdered glycine.

Load standard ¹³C NMR parameters. Spin the sample at 4 kHz so that the duration zp of one rotor period is 250 ys, and first run a normal CP/MAS spectrum (see Exp.

14.4). Then load the SELTICS pulse sequence. You have to set:

td: 4k sw: 500 ppm o1: middle of '\C NMR spectrum o2: middle of ¹H NMR spectrum p!: 90° ¹H decoupler pulse p2:¹H 5 ms spin-lock decoupler pulse p3: ¹³C 5 ms spin-lock transmitter pulse p4: ¹³C transmitter pulse, duration zp/12 = 20.8 μs p5: ¹³C transmitter pulse, duration zp/12 = 20.8 μs pé: ¹³C transmitter pulse, duration 7p/24 = 10.4 μs p7: ¹³C transmitter pulse, duration zp/24 = 10.4 μs d1:3s d2: 20.8 pus, calculated from zp/12 d3: 41.6 μs, calculated from 7/6 decoupler attenuation for cross-polarization decoupler attenuation for high-power cw decoupling, typically 2 dB less than for cross-polarization; on instruments with no fast power switching use same attenuation as for cross-polarization rg: receiver gain for correct ADC input de: as short as possible

5. Processing

Use standard 1D processing for ¹³C NMR as described in Experiment 3.2 with zero-filling to 4 k and exponential multiplication corresponding to the line-width using lb =

6. Result

The figure shows the spectra of glycine obtained using a dual solid-state probe-head with a 4 mm rotor on an MSL-300 spectrometer. The spinning rate was 4000 Hz as seen from the normal CP/MAS spectrum in a, whereas in b the result of the SELTICS