Protocol: Redor1tancp  Sequence: redor1tancp.c  Apptype:  solidseq1d

Description: 

Rotational Echo Double Resonance (REDOR) with constant, linear or 
tangent-ramped CP preparation, XY8 decoupling with pulses alternating 
on X and Y, with a choice of SPINAL64 or TPPM decoupling during both 
acquisition and REDOR evolution. Used to measure XY bond distances for 
organic materials. 

Additional Software:

reset_redor1 - This macro uses the calibrated values of pwX90 and pwY90 
to set up xy8XY.  The parameters for decoupling in Htppm and Hspinal 
are copied to Hmixtppm and Hmixspinal. 
 
redoranal1 - This macro creates a deltaS/S plot for REDOR data obtained as 
a double array of cycles with alternating control and REDOR spectra. 

Setup: 

Be sure that an HXY probe is set up for three-channel observe and set 
the parameters probeConnect and preAmpConfig in the Channels page. 13C-
15N glycine, 10% in natural abundance, is an excellent REDOR standard. 

Load a calibrated data set and select the protocol Redor1tancp. For new 
nuclei calibrate pwX90 and pwY90 with Onepul and Tancpx and then select 
Redor1tancp. 

Select the desired decoupling method, TPPM or SPINAL. The manual file 
onepul describes calibration of decoupling. 

Calibrate the obs X nucleus with Onepul or Tancpx and place the 
resonance for which REDOR will be observed on-resonance. 

To calibrate the third channel Y nucleus set it as obs and be sure that 
the obs transmitter switches to the correct transmitter, 3 or 4. The 
switch will take place if the Y nucleus is in the correct position of 
probeConnect. See the manual file tunerp for instructions in setting up 
three-channel experiments and observing on the third channel. Be sure 
the third-channel nucleus is on resonance. 

With third-channel obs copy calibrations aY90 = aX90 and pwY90 = pwX90. 
Also set dof2 = tof. Return to the original obs nucleus and restore the 
original calibrations for channel-two obs.  

Select Redor1tancp.  The protocol sets aXxyxy8 = aX90, aYxyxy8 = aY90, 
pwXxyxy8 = 2.0*pwX90 and pwYxyxy8 = 2.0*pwY90.  Set fXYxy8 = 0.5.  

Read the name aXxyxy8 as the "amplitude of the X channel for the group 
xy8XY located on the X and Y channels" of the sequence.  Note that the 
'xy"of "xy8" refers to the 0 and 90-degree phases of the sequence while 
the "Xxy" refers to the fact that the amplitude is applied to the X 
channel of two possible choices "x" and "y'. 

Set nXYxy8 = 0 and onXYxy8 = 1 to collect a CP spectrum with no REDOR 
evolution. 

Array nXYxy8 from 0 to 64 in steps of 8 to observe the T2 of the 
observe nucleus. Optimize TPPM or SPINAL decoupling during REDOR 
evolution with the parameters of Hmixtppm or Hmixspinal. It is helpful 
to set nXYxy8 = 32 and array the parameters of TPPM or SPINAL for 
maximum intensity. Note that line width is unaffected because one is 
optimizing T2 during REDOR evolution. 

First array nXYxy8 from 0 to 64 in steps of 2. Then set onXYxy8 = 1,2. 
Collect the REDOR data. 

To process, pick the peak of interest and type fp on the command line. 
Type redoranal1 on the command line and enter the fraction natural 
abundance to cause the REDOR curve to approach 1.0. 

Parameter Groups:

90H:  Module:  no
Sequence:  tancpx.c  
Description:  Provides a 90-degree pulse on dec that can be used as a 
              preparation pulse. Also used to store the dec calibration.
Parameters:  Channels Page
       aH90  - the amplitude of the pulse.
       pwH90 - the pulse length.

cpHX:  Module:  yes
Sequence:  tancpx.c
Description:  Implements constant, linear or tangent-ramped cross 
              polarization from dec to obs. 
Parameters:  Sequence Page
       shHX - 'c', constant, 'l', linear and 't', tangent shape on the 
              channel designated with chHX. 
       chHX - the variable-amplitude channel, 'fr' from or 'to', to. 
       aHhx - median amplitude of the dec channel.
       aXhx - median amplitude of the obs channel.
       bHX - +/- tangent curvature (>0 to 1.0e5).  
       dHX - amplitude width of the ramp. A negative width sets a ramp 
              that starts high and decreases in amplitude.
       tHX - contact time
       ofHX - overall offset on the variable channel
       frHX = 'dec' -  channel with the initial polarization (must be 
              set - not shown).           
       toHX = 'obs' -  channel with the final polarization (must be set 
              - not shown). 
Implementation:  CP hx = getcp("HX",0.0,0.0,0,1); 
Underscore functions: _cp_(hx,phHhx,phXhx);  

xy8XY:  Module:  no
Sequence:  redor1tancp.c     
Description:  Implements obs pulses at each rotor period with the XY8 
              phase cycle and implements dec2 pulses within each rotor period 
              with the XY8 phase cycle, used for REDOR evolution.
Parameters:  Sequence Page
       aXxyxy8 - amplitude of the obs pulses. 
       aYxyxy8 - amplitude of the dec2 pulses. 
       pwXxyxy8 - 180-degree flip on obs. 
       pwYxyxy8 - 180-degree flip on dec2. 
       fXYxy8 - position of the dec2 pulse, 0.5 is the middle of the 
              rotor period.
       nXYxy8 - number of rotor cycles. 
       onYxyxy8 - "2" provides dec2 pulses and "1" is a control without 
              dec2 pulses. 

Hmixseq:  Module: yes 
Sequence:  redor1tancp.c
Description:  Chooses SPINAL or TPPM decoupling on the dec channel
              during F1 and mixing periods when Hseq is used for
              acquisition.
Parameters:  Sequence Page - the Hmixspinal and Hmixtppm groups
              overlap.  Hmixseq chooses the decoupling sequence TPPM
              or SPINAL.
Implementation:  DSEQ mix = getdseq("H"); The router implements
              getspinal() or gettppm(), as selected.
Underscore functions:  _dseqon(mix); runs _tppm(); or _spinal();
             _dseqoff(mix); runs decprgoff(mix);

Hmixspinal:  Module: yes
Sequence:  redor1tancp.c
Description:  Implements SPINAL decoupling on the dec channel during
              typical F1 and mixing periods when Hspinal is used for
              acquisition.
Parameters:  Sequence Page
       aHmixspinal - amplitude of the dec channel.
       pwHmixspinal - approximate 180-degree flip.
       phHmixspinal - +/- small angle phase. SPINAL64 is implemented
              with phases = +/- 1.0, +/- 1.5 and +/-2.0 times
              phHmixspinal.
       chHmixspinal = 'dec' must be set (not shown).
Implementation: SPINAL mix = getspinal("H"); or DSEQ mix =
             getdseq("H");
Underscore functions: _spinal(mix); and decprgoff(); or _dseqon(mix);
             and _dseqoff(mix);
        
Hmixtppm:  Module: yes
Sequence:  redor1tancp.c
Description:  Implements TPPM decoupling on the dec channel during
              typical F1 and mixing periods when Htppm is used for
              acquisition.
Parameters:  Sequence Page
       aHmixtppm - amplitude of the dec channel.
       pwHmixtppm - approximate 180-degree flip angle on resonance.
       phHmixtppm - +/- small angle phase. TPPM is implemented
              with phases = +/- 1.0 times phHmixtppm for alternating
              pulses.
       chHmixtppm = 'dec' must be set (not shown).
Implementation: TPPM mix = gettppm("H"); or DSEQ mix = getdseq("H");
Underscore functions: _tppm(mix); and decprgoff(); or _dseqon(mix); and
              _dseqoff(mix);

Hseq:  Module:  yes 
Sequence:  tancpx.c      
Description:  Chooses SPINAL or TPPM decoupling on the dec channel 
              during acquisition.
Parameters:  Sequence Page - the Hspinal and Htppm groups overlap. 
       Hseq - chooses the decoupling sequence, TPPM or SPINAL. 
Implementation:  DSEQ dec = getdseq("H");  The router implements 
              getspinal() or gettppm(). 
Underscore functions: _dseqon(dec); runs _tppm(); or _spinal();
              _dseqoff(dec); runs decprgoff();  

Hspinal:  Module:  yes 
Sequence:  tancpx.c  
Description:  Implements SPINAL decoupling on the dec channel during 
              acquisition.  
Parameters:  Sequence Page
       aHspinal - amplitude of the dec channel. 
       pwHspinal - approximate 180-degree flip angle on resonance. 
       phHspinal - +/- small angle phase. SPINAL64 is implemented with 
               phases = +/- 1.0, +/- 1.5 and +/-2.0 times phHspinal. 
       chHspinal = 'dec' must be set (not shown).
Implementation: SPINAL dec = getspinal("H"); or DSEQ dec = 
               getdseq("H");  
Underscore functions: _spinal(dec); and decprgoff(); or _dseqon(dec); 
               and _dseqoff(dec);   

Htppm:  Module:  yes 
Sequence:  tancpx.c      
Description:  Implements TPPM decoupling on the dec channel during 
              acquisition.  
Parameters:  Sequence Page
       aHtppm - amplitude of the dec channel. 
       pwHtppm - approximate 180-degree flip angle on resonance. 
       phHtppm - +/- small angle phase. TPPM is implemented 
              with phases = +/- 1.0 times phHtppm for alternating pulses.  
       chHtppm = 'dec' must be set (not shown).
Implementation: TPPM dec = gettppm("H"); or DSEQ dec = getdseq("H");   
Underscore functions: _tppmon(dec); and decprgoff(); or _dseqon(dec); 
              and _dseqoff(dec);   
