1-Pyrroline, C4H7N
























 





 





 









Nitrogen


Nuclear Quadrupole Coupling Constants

in 1-Pyrroline

 








 








 

 





Calculation of the nitrogen nqcc's in 1-pyrroline (aka 3,4-dihydro-2H-pyrrole) was made here on ropt molecular structures given by MP2/6-311+G(2d,2p) and MP2/aug-cc-pVTZ optimization.  These are compared with the experimental nqcc's [1] in Table 1.  Structure parameters are given in Table 2, rotational constants in Table 3.

 








In Table 1, subscripts a,b,c refer to the principal axes of the inertia tensor; x,y,z to the principal axes of the nqcc tensor.  Ø (degrees) is the angle between its subscripted parameters.  ETA = (Xxx - Xyy)/Xzz.

 








RMS is the root mean square difference between calculated and experimental nqcc's (percentage of the average of the magnitudes of the experimental nqcc's).  RSD is the calibration residual standard deviation of the B3PW91/6-311+G(df,pd) model for calculation of nitrogen nqcc's.

 








 








   







Table 1. 14N nqcc's in 1-Pyrrolidine (MHz).  Calculation was made on the (1) MP2/6-311+G(2d,2p) and (2) MP2/aug-cc-pVTZ ropt molecular structures.
   









Calc (1)
Calc (2)
Expt [1]
   







Xaa -
 4.420 -
 4.435 -
 4.39(10)

Xbb
1.284
1.295
1.04(10)

Xcc
3.136
3.140
3.35(10)

Xab -
 0.955 -
 0.892



Xac -
 0.469
 -
 0.481



Xbc -
 0.084
 -
 0.079



 







RMS
0.188 (6.4 %) 0.192 (6.6 %)  

RSD
0.030 (1.3 %) 0.030 (1.3 %)


 







Xxx
1.439
1.430



Xyy
3.165
3.171



Xzz - 4.605 - 4.602



ETA
0.375
0.378



Øz,bi *
9.17
9.07



 








 








* Angle between the z-principal axis and the bisector of the CNC angle.

 







 
 

Table 2.  1-Pyrroline molecular structure parameters, ropt(1) = MP2/6-311+G(2d,2p) optimization and ropt(2) = MP2/aug-cc-pVTZ optimization (Å and degrees).
 


 C
 C,1,B1
 N,2,B2,1,A1
 C,3,B3,2,A2,1,D1,0
 C,4,B4,3,A3,2,D2,0
 H,1,B5,2,A4,3,D3,0
 H,2,B6,1,A5,5,D4,0
 H,2,B7,1,A6,5,D5,0
 H,4,B8,3,A7,2,D6,0
 H,5,B9,4,A8,3,D7,0
 H,5,B10,4,A9,3,D8,0
 H,1,B11,2,A10,3,D9,0


ropt(1) ropt(2)
 

 B1=1.5397481
 B2=1.47894139
 B3=1.28123894
 B4=1.51051369
 B5=1.08552817
 B6=1.08585939
 B7=1.09015021
 B8=1.08395024
 B9=1.0870939
 B10=1.09150085
 B11=1.08745494
 A1=106.43758491
 A2=107.7721161
 A3=116.36966484
 A4=113.01563843
 A5=113.47269772
 A6=112.13489423
 A7=120.03786504
 A8=112.86727336
 A9=109.47535158
 A10=109.69625567
 D1=15.34698044
 D2=-0.19242658
 D3=-146.04629055
 D4=-144.04729095
 D5=93.75069535
 D6=177.70345543
 D7=-136.61145026
 D8=103.80996916
 D9=93.08546015
  B1=1.53768936
 B2=1.47515699
 B3=1.28091379
 B4=1.50735347
 B5=1.08778683
 B6=1.08837722
 B7=1.09291486
 B8=1.08542848
 B9=1.0892125
 B10=1.09398507
 B11=1.08984022
 A1=106.46858466
 A2=107.67816308
 A3=116.36448951
 A4=113.02340285
 A5=113.49596145
 A6=112.06424776
 A7=120.06252446
 A8=112.89055124
 A9=109.38117858
 A10=109.66832463
 D1=15.70665011
 D2=-0.31655648
 D3=-146.46997085
 D4=-144.57848819
 D5=93.28044781
 D6=177.72286047
 D7=-136.91453336
 D8=103.54102108
 D9=92.56411946






 














Table 3.  1-Pyrroline Rotational Constants (MHz).  ropt(1) = MP2/6-311+G(2d,2p),  ropt(2) = MP2/aug-cc-pVTZ optimized structures.
 





 
ropt(1) ropt(2) Expt [1]








A
 7787.4
 7806.1
 7737.83(14)


B
 7426.6
 7442.8
 7386.78(11)


C
 4152.2
 4166.1
 4111.22(3)


 








 








[1] G.B.Edwards, K.Yamanouchi, K.Kuchitsu, M.Sugie, H.Takeo, and C.Matsumura, J.Mol.Spectrosc. 111,301(1985).

 








 








Pyrrolidine
 Pyrrole

 








 








Table of Contents




Molecules/Nitrogen




 








 













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Last Modified 13 May 2013