2,3-F2-C6H3CN

















 





 





Nitrogen

Nuclear Quadrupole Coupling Constants


in 2,3-Difluorobenzonitrile


 








 








 

 





Calculation of the nitrogen nqcc's in 2,3-difluorobenzonitrile was made here on a molecular structure given by B3P86/6-31G(3d,3p) optimization.  These are compared with the experimental nqcc's of Onda et al. [1] and Kamaee et al. [2] in Table 1.  Structure parameters are given in Z-matrix format in Table 2, rotational constants and quartic centrifugal distortion 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.  The nqcc y-axis is chosen coincident with the inertia c-axis, these are perpendicular to the molecular plane.  Ø (degrees) is the angle between its subscripted parameters.  ETA = (Xxx - Xyy)/Xzz.

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

 








 








 








Table 1. Nitrogen nqcc's in 2,3-Difluorobenzonitrile (MHz).  Calculation was made on the B3P86/6-31G(3d,3p) ropt structure.












Calc.
Expt. [1]
Expt. [2]
 








Xaa - 3.885 - 3.856(10) -
 3.8693(5) *

Xbb
1.901
1.860(14)
1.8715(5) *

Xcc
1.984
1.996(14)
1.9978(5) *

|Xab|
1.679














RMS


0.030 (1.2 %)
0.021 (0.82 %)

RSD


0.030 (1.3 %)
0.030 (1.3 %)










Xxx
2.353





Xyy
1.984





Xzz - 4.337





ETA - 0.0852





Øz,a
15.07





Øa,CN
15.05





Øz,CN
  0.02















 








* Calculated here from the experimental 1.5Xaa = -5.80400(76) and 0.25(Xbb - Xcc) = -0.03156(20) MHz..

 







 
 



Table 2.  2,3-Difluorobenzonitrile.  Molecular structure parameters, ropt (Å and degrees).
 




 C
 C,1,B1
 C,2,B2,1,A1
 C,3,B3,2,A2,1,D1,0
 C,4,B4,3,A3,2,D2,0
 C,1,B5,2,A4,3,D3,0
 C,6,B6,1,A5,2,D4,0
 N,7,B7,1,A6,6,D5,0
 F,1,B8,6,A7,5,D6,0
 F,2,B9,1,A8,6,D7,0
 H,3,B10,2,A9,1,D8,0
 H,4,B11,3,A10,2,D9,0
 H,5,B12,4,A11,3,D10,0








 B1=1.3885635
 B2=1.38319075
 B3=1.39146954
 B4=1.38516255
 B5=1.39458384
 B6=1.42561542
 B7=1.15746083
 B8=1.32633347
 B9=1.33141821
 B10=1.08378502
 B11=1.08335261
 B12=1.0826961
 A1=120.70657844
 A2=119.42846989
 A3=120.4888765
 A4=120.06723678
 A5=119.79745481
 A6=151.5957649
 A7=120.44279732
 A8=118.68729594
 A9=118.6285415
 A10=119.63329627
 A11=121.10559197
 D1=0.
 D2=0.
 D3=0.
 D4=180.
 D5=180.
 D6=180.
 D7=180.
 D8=180.
 D9=180.
 D10=180.








 













Table 3.  2,3-Difluorobenzonitrile.  B3P86/6-31G(3d,3p) rotational constants (MHz) and B3LYP/cc-pVTZ quartic centrifugal distortion constants (kHz).
 






Calc ropt     Expt. [2]






A
2270.0 2260.152021(47)

B
1187.3 1182.866459(15)

C
  779.5   776.3845304(91)






Delta_J
0.0331
 0.034910(91)

Delta_JK
0.163
 0.17894(45)

Delta_K
 -
 0.0403
 0.0479(27)

delta_j
0.0122
 0.012851(41)

delta_k
0.149
 0.16072(59)



 








 








[1] M.Onda, T.Kasagi, and A.I.Jaman, J.Mol.Struct. 612,167(2002).

[2] M.Kamaee, M.Sun, H.Luong, and J. van Wijngaarden, J.Phys.Chem. A 119(41),10279(2015).

 








 








Benzonitrile Pentafluorobenzonitrile

o-Fluorobenzonitrile o-Tolunitrile

m-Fluorobenzonitrile m-Tolunitrile

p-Fluorobenzonitrile p-Tolunitrile

2,4-Difluorobenzonitrile





 








 








Table of Contents





Molecules/Nitrogen




 








 













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Last Modified 30 Sept 2015