C5H9N
















 









Nitrogen


Nuclear Quadrupole Coupling Constants


in 3-Methylbutyronitrile



 








 








Nitrogen nqcc'c in anti and gauche conformers of 3-methylbutyronitrile shown below were determined by Wehres et al. [1].












    anti



gauche






























Calculations of the nitrogen nqcc tensors were made on an approximate equilibrium structures (~re) given by MP2/6-311+G(3df,3pd) optimization with empirically corrected CC and CN bond lengths.   These calculated nqcc's are compared with the experimental results in Tables 1 and 2.  Structure parameters are given in Table 3, rotational constants in Table 4.

 








In Tables 1 and 2, subscripts a,b,c refer to the principal axes of the inertia tensor; x,y,z to the principal axes of the nqcc tensor.  ETA = (Xxx - Xyy)/Xzz.  Ĝ (degrees) is the angle between its subscripted parameters.


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

 








 








 
   







Table 1.  Nitrogen nqcc's in anti 3-Methylbutyronitrile (MHz).  Calculation was made on ~re molecular strcuture.
   










Calc

Expt. [1]
   






14N Xaa -
3.050
-
3.07713(67)



Xbb
1.214

1.24843(87)



Xcc
1.836

1.82870(66)



Xab -
2.163





Xac
1.151





Xbc
0.420













RMS

0.025 (1.2 %)





RSD

0.030 (1.3 %)












Xxx
2.043





Xyy
2.160




Xzz -
4.203





ETA

0.0278





Ĝz,CN














 








 









   







Table 2.  Nitrogen nqcc's in gauche 3-Methylbutyronitrile (MHz).  Calculation was made on ~re molecular strcuture.
   










Calc

Expt. [1]
   






14N Xaa -
1.378
-
1.44002(59)



Xbb
2.015

2.01104(76)



Xcc -
0.637
-
0.57102(66)



Xac -
3.174













RMS

0.052 (3.9 %)





RSD

0.030 (1.3 %)












Xxx
2.015





Xyy
2.188




Xzz -
4.203





ETA

0.0412





Ĝz,CN














 













Table 3.  3-Methylbutyronitrile: MP2/6-311+G(3df,3pd) optimized structure parameters, with approximate equilibrium bond lengths (~re) given in parentheses.





            anti
          gauche


 C
 C,1,B1
 H,2,B2,1,A1
 H,1,B3,2,A2,3,D1,0
 H,1,B4,2,A3,3,D2,0
 H,1,B5,2,A4,3,D3,0
 C,2,B6,1,A5,5,D4,0
 C,2,B7,1,A6,7,D5,0
 H,7,B8,2,A7,1,D6,0
 H,7,B9,2,A8,1,D7,0
 H,7,B10,2,A9,1,D8,0
 H,8,B11,2,A10,1,D9,0
 H,8,B12,2,A11,1,D10,0
 C,8,B13,2,A12,1,D11,0
 N,14,B14,2,A13,1,D12,0
 C
 C,1,B1
 H,2,B2,1,A1
 H,1,B3,2,A2,3,D1,0
 H,1,B4,2,A3,3,D2,0
 H,1,B5,2,A4,3,D3,0
 C,2,B6,1,A5,5,D4,0
 C,2,B7,1,A6,7,D5,0
 H,7,B8,2,A7,1,D6,0
 H,7,B9,2,A8,1,D7,0
 H,7,B10,2,A9,1,D8,0
 H,8,B11,2,A10,1,D9,0
 H,8,B12,2,A11,1,D10,0
 C,8,B13,2,A12,1,D11,0
 N,14,B14,8,A13,2,D12,0






 B1=1.52242121     (1.5203)
 B2=1.09266218
 B3=1.08934663
 B4=1.08921845
 B5=1.09173382
 B6=1.52294086     (1.5206)
 B7=1.53492397     (1.5322)
 B8=1.08991737
 B9=1.09142207
 B10=1.089111
 B11=1.09235812
 B12=1.09083247
 B13=1.45934342   (1.4602)
 B14=1.16982551   (1.1564)
 A1=108.92169314
 A2=111.55375803
 A3=110.56620483
 A4=110.19950287
 A5=111.15152338
 A6=110.84308845
 A7=111.56177437
 A8=110.31987051
 A9=110.66657166
 A10=109.54887994
 A11=110.45287722
 A12=112.12652579
 A13=143.22730256
 D1=-59.30943958
 D2=61.15229745
 D3=-179.57031831
 D4=-59.01154317
 D5=-121.50788792
 D6=179.26325682
 D7=-60.48332502
 D8=58.81600963
 D9=60.37108753
 D10=178.60271574
 D11=-60.24503313
 D12=-54.46119695
 B1=1.52283823     (1.5207)
 B2=1.09274994
 B3=1.0901029
 B4=1.08919971
 B5=1.09082136
 B6=1.52283823     (1.5207)
 B7=1.53683957     (1.5340)
 B8=1.0901029
 B9=1.09082136
 B10=1.08919971
 B11=1.0909123
 B12=1.0909123
 B13=1.46086913    (1.4617)
 B14=1.16995947    (1.1565)
 A1=108.88883651
 A2=111.44533917
 A3=110.53863322
 A4=110.40465686
 A5=111.17652094
 A6=110.84384673
 A7=111.44533917
 A8=110.40465686
 A9=110.53863322
 A10=110.41847089
 A11=110.41847089
 A12=111.53415009
 A13=178.0510418
 D1=-59.3265669
 D2=60.98404473
 D3=-179.58139441
 D4=-58.98227523
 D5=-123.76672187
 D6=179.29288686
 D7=-60.45228563
 D8=58.98227523
 D9=-177.51575622
 D10=-58.52710727
 D11=61.97856825
 D12=0.













Table 4.  3-Methylbutyronitrile:  Rotational Constants (MHz).

 





   ~re      Expt. [1]






anti
A   7470.
7363.745484(92)


B   2136.
2107.1641996(219)


C   1787.
1762.0787378(211)






gauche
A
  5324.
5293.815739(54)


B
  2504.
2456.4351918(226)


C
  2324.
2270.2489771(220)







 








tert Butyl Cyanide
2-Methylbutyronitrile n-Butyl Cyanide


































[1] N.Wehres, M.Hermanns, O.H.Wilkins, K.Borisov, F.Lewen, J.-U.Grabow, S.Schlemmer, H.S.P.Müller, A&A 615,A140(2018).


 








N.Wehres, M.Hermanns, O.H.Wilkins, K.Borisov, F.Lewen, J.-U.Grabow, S.Schlemmer, H.S.P.Müller, Abstract WJ04, 72rd ISMS, Champaign-Urbana, Illinois, 2018.

 









 








Table of Contents




Molecules/Nitrogen




 








 













3MeBuCN.html






Last Modified 28 April 2018