40-phase cycling of the second and the third pulses in 3-pulse z-filter ±5Q-MAS of I = 5/2
[an error occurred while processing this directive]Z-filter 5Q-MAS with 40-phase cycling
Two approaches:
(1) filtering the coherences,
(2) explicit phase cycling the pulses and the receiver,
are used for the simulation of echo and antiecho amplitude in
±5Q-MAS of spin I = 5/2 system. The sequence consists of two
strong amplitude pulses followed by a weak amplitude pulse.
(1) 40-phase cycling the second and the third pulses
| φ1 = | 0° |
|---|---|
| φ2 = | 0° 36° 72° 108° 144° 180° 216° 252° 288° 324° |
| φ3 = | {0°}X10 {90°}X10 {180°}X10 {270°}X10 |
| φrec = | {0° 180°}X5 {90° 270°}X5 {180° 0°}X5 {270° 90°}X5 |
This 40-phase cycling selects the three families of coherence transfer pathways:
- 0Q -> -1Q -> +4Q -> -1Q,
- 0Q -> +1Q -> -4Q -> -1Q,
- 0Q -> ±5Q -> +0Q -> -1Q (the desired coherence transfer pathways),
as shown in the following figure. Family a is yellow pathway, family b is brown pathway, and family c is red pathways:
(2) Simulation
We provide SIMPSON2 Tcl scripts for simulating the echo and antiecho
amplitude versus a pulse duration:
(1) filtering the coherences (a Tcl script is associated with each family),
(2) 40-phase cycling the pulses and the receiver.
| Duration | Filtering | 40-phase cycling |
|---|---|---|
| 1st-pulse |
a + b + c: total-p1 |
al-p2p3-cycl-p1 |
| 2nd-pulse |
a + b + c: total-p2 |
al-p2p3-cycl-p2 |
| 3rd-pulse |
a + b + c: total-p3 |
al-p2p3-cycl-p3 |
(top)