CH3CH2CH(CN)CH3































 






Nitrogen


Nuclear Quadrupole Coupling Constants


in anti 2-Methylbutyronitrile


 
(2-Cyano-anti-butane)



 








 
Click for 2-Methylbutyronitrile gauche 













Calculations of the nitrogen nqcc tensor in anti 2-methylbutyronitrile was made on an approximate equilibrium structure (~re) given by MP2/aug-cc-pVTZ optimization with empirically corrected CC and CN bond lengths.   These calculated nqcc's are compared with the experimental results of Müller, et al. [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.  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 2-Methylbutyronitrile (MHz).  Calculation was made on ~re molecular strcuture.
   









Calc
Expt. [1]
   






14N Xaa
0.330
0.29545(32)


Xbb -
 2.168
 -
 2.14468(35)


Xcc
1.838
1.84923(19)


Xab
2.740
2.642(100)


Xac -
 0.712




Xbc
1.065












RMS
0.025 (1.8 %)




RSD
0.030 (1.3 %)












Xxx
2.077




Xyy
2.125




Xzz -
 4.202




ETA
0.0113




Ĝz,CN
  0.29












 








 












Table 2.  anti 2-Methylbutyronitrile: MP2/aug-cc-pVTZ optimized structure parameters, with approximate equilibrium bond lengths (~re) given in parentheses.





 C
 C,1,B1
 H,1,B2,2,A1
 H,1,B3,2,A2,3,D1,0
 H,1,B4,2,A3,3,D2,0
 C,2,B5,1,A4,3,D3,0
 H,2,B6,1,A5,6,D4,0
 C,6,B7,2,A6,1,D5,0
 H,6,B8,2,A7,1,D6,0
 H,6,B9,2,A8,1,D7,0
 H,8,B10,6,A9,2,D8,0
 H,8,B11,6,A10,2,D9,0
 H,8,B12,6,A11,2,D10,0
 C,2,B13,1,A12,6,D11,0
 N,14,B14,1,A13,2,D12,0





 B1=1.52962101     (1.5272)
 B2=1.08842069
 B3=1.08944302
 B4=1.08927868
 B5=1.53303737      (1.5305)
 B6=1.09375171
 B7=1.5218576        (1.5198)
 B8=1.09206825
 B9=1.09232185
 B10=1.08893123
 B11=1.08986718
 B12=1.09059829
 B13=1.46359877     (1.4641)
 B14=1.17195715     (1.1568)
 A1=111.30658065
 A2=110.19820874
 A3=109.51573327
 A4=111.93791095
 A5=109.29238563
 A6=113.04128558
  A7=107.33784999
 A8=108.42743763
 A9=110.90595516
 A10=110.90765845
 A11=110.82442103
 A12=110.04745597
 A13=143.73647304
 D1=120.31675849
 D2=-120.28853164
 D3=179.47849667
 D4=-120.27195682
 D5=-177.89880028
 D6=-55.96308853
 D7=59.4166924
 D8=179.10263462
 D9=-60.81354819
 D10=59.20484418
 D11=122.57858463
 D12=177.61866765







 













Table 3.  anti 2-Methylbutyronitrile:  Rotational Constants (MHz).

 





   ~re      Expt. [1]







A   4093.
 4070.369407(21)


B   3203.
 3145.923481(17)


C   1946.
 1919.400332(9)







 








 








[1] H.S.P.Müller, O.Zingsheim, N.Wehres, J.-U.Grabow, F.Lewen, S.Schlemmer, J.Phys.Chem. A, 121(38),7121(2017).

 








H.S.P.Müller, N.Wehres, O.Zingsheim, F.Lewen, S.Schlemmer, J.-U.Grabow, R.T.Garrod,  A.Belloche, and K.M.Menten, Abstract MF03, 72nd ISMS, Champaign-Urbana, Illinois, 2017.

 








 








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Molecules/Nitrogen




 








 













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Last Modified 6 Sept 2017