NC-CH2CH2CH2-CN

























 









Nitrogen


Nuclear Quadrupole Coupling Constants


in Glutaronitrile



 
(Pentanedinitrile)




 








 








Calculations of the nitrogen nqcc tensors in both GG and GT conformers of glutaronitrile were made on approximate equilibrium structures (~re) given by MP2/aug-cc-pVTZ optimization with empirically corrected CC and CN bond lengths.   These calculated nqcc's for GG are given in Table 1, and for GT are compared with the experimental results of Hays, et al. [1] in Tables 2 -3.  Structure parameters are given in Table 4, rotational constants in Table 5.

 


































GG Conformer


GT Conformer





















In Tables 1 - 3, 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.  (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 GG-Glutaronitrile (MHz).  Calculation was made on ~re molecular strcuture.
   










Calc

Expt.

   






14N Xaa -
0.282





Xbb -
0.006





Xcc
0.288





Xab +/-
2.190





Xac -
2.192





Xbc +/- 2.012













RMS







RSD

0.030 (1.3 %)












Xxx
2.231





Xyy
2.046




Xzz -
4.277





ETA
-
0.0434





z,CN
0.73













 








 








   







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










Calc

Expt. [1]
   






14N (G)
Xaa
0.681

0.559(26)



Xbb -
2.675
-
2.540(21) *



Xcc
1.994

1.981(21) *



Xab
2.732





Xac
0.382





Xbc -
0.602













RMS

0.105 (6.2 %)





RSD

0.030 (1.3 %)












Xxx
2.219





Xyy
2.064




Xzz -
4.284





ETA
-
0.0363





z,CN
0.59













 








* Derived here from  and Xaa and Xbb - Xcc = -4.5220(332) MHz.


 









 









   







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










Calc

Expt. [1]
   






14N (T)
Xaa -
3.702
-
3.6501(153)



Xbb
2.086

2.0580(172) *



Xcc
1.616

1.5920(172) *



Xab -
0.380





Xac -
1.760





Xbc -
0.186













RMS

0.037 (1.5 %)





RSD

0.030 (1.3 %)












Xxx
2.200





Xyy
2.059




Xzz -
4.259





ETA
-
0.0329





z,CN
0.45













 









* Derived here from  and Xaa and Xbb - Xcc = 0.4660(308) MHz.

 













Table 4.  Glutaronitrile: MP2/aug-cc-pVTZ optimized GG and GT 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
  C,2,B4,1,A3,3,D2,0
  H,2,B5,1,A4,5,D3,0
  H,2,B6,1,A5,5,D4,0
  H,5,B7,2,A6,1,D5,0
  H,5,B8,2,A7,1,D6,0
  C,1,B9,2,A8,5,D7,0
  N,10,B10,1,A9,2,D8,0
  C,5,B11,2,A10,1,D9,0
  N,12,B12,5,A11,2,D10,0
 C
 C,1,B1
 H,1,B2,2,A1
 H,1,B3,2,A2,3,D1,0
 C,2,B4,1,A3,4,D2,0
 H,2,B5,1,A4,5,D3,0
 H,2,B6,1,A5,5,D4,0
 H,5,B7,2,A6,1,D5,0
 H,5,B8,2,A7,1,D6,0
 C,1,B9,2,A8,5,D7,0
 N,10,B10,2,A9,1,D8,0
 C,5,B11,2,A10,1,D9,0
 N,12,B12,2,A11,1,D10,0






GG Conformer
GT Conformer






 B1=1.5312203       (1.5287)
 B2=1.0896688
 B3=1.09160952
 B4=1.5312203       (1,5287)
 B5=1.08985667
 B6=1.08985667
 B7=1.0896688
 B8=1.09160952
 B9=1.46011            (1.4894)
 B10=1.17110199    (1.1562)
 B11=1.46011          (1.4894)
 B12=1.17110199    (1.1562)
 A1=110.4237506
 A2=110.33314587
 A3=112.18925853
 A4=108.57702509
 A5=109.70445367
 A6=110.4237506
 A7=110.33314587
 A8=110.83051949
 A9=176.95283142
 A10=110.83051949
 A11=176.95283142
 D1=118.92909051
 D2=-179.26287149
 D3=121.41507607
 D4=-120.76614775
 D5=-179.26287149
 D6=-60.33378098
 D7=60.0544048
 D8=-5.78087694
 D9=60.0544048
 D10=-5.7808769
 B1=1.53016699       (1.5277)
 B2=1.09140582
 B3=1.0915984
 B4=1.53078065       (1.5283)
 B5=1.08981648
 B6=1.0897515
 B7=1.08981365
 B8=1.09129662
 B9=1.45846203        (1.4592)
 B10=1.17070468      (1.1560)
 B11=1.46038574      (1.4610)
 B12=1.17102393      (1.1562)
 A1=110.30300781
 A2=110.40097774
 A3=111.43676815
 A4=109.46127176
 A5=109.74867365
 A6=110.31412432
 A7=110.47976068
 A8=111.13924709
 A9=178.11626844
 A10=111.38823056
 A11=177.52904259
 D1=118.63284626
 D2=-60.91906566
 D3=121.62263973
 D4=-120.49807271
 D5=179.92830434
 D6=-61.40549905
 D7=178.24716218
 D8=-8.3079948
 D9=59.11430996
 D10=-14.50804825








 













Table 5.  Glutaronitrile:  Rotational Constants (MHz).

 





  ~re    Expt. [1]






GG Conformer
A   4565.
4756.1343(39)


B   1634.
1582.8040(48)


C   1479.
1449.29077(259)






GT Conformer
A
  7299.
7349.2634(57)


B
  1228.
1207.02006(228)


C
  1105.
1088.74492(204)


 








 








[1] B.M.Hays, D.Mehta-Hurt, K.M.Jawad, A.O.Hernandez-Castillo, C.Abeysekera, D.Zhang, and  T.S.Zwier, Abstract WC01, 72nd ISMS, Champaign-Urbana, Illinois, 2017.


 








 








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Last Modified 22 Aug 2017