o-C6H4FCN PDF































 





Nitrogen

Nuclear Quadrupole Coupling Constants


in ortho-Fluorobenzonitrile


 








 








 

 





Calculation of the nitrogen nqcc's in o-fluorobenzonitrile was made here on a molecular structure given by B3P86/6-31G(3d,3p) optimization.  These are compared with the experimental nqcc's [1 - 3] 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 efg's/nqcc's.

 








 








 








Table 1. 14N nqcc's in o-Fluorobenzonitrile (MHz).  Calculation was made on the B3P86/6-31G(3d,3p) ropt structure.












Calc.
Expt. [1,2]
Expt. [3]
 








Xaa - 4.192 - 4.147(7) -
 4.18239(50) *

Xbb
2.250
2.223(6)
2.21275(47) *

Xcc
1.942
1.924(6)
1.96963(47) *

|Xab|
0.824














RMS


0.032 (1.1 %)
0.027 (0.97 %)

RSD


0.030 (1.3 %)
0.030 (1.3 %)










Xxx
2.353


2.317(13) **

Xyy
1.942


1.96963(47)

Xzz - 4.295

-
 4.287(13)

ETA - 0.0957

-
 0.0811(32)

Øz,a
7.17


7.22

Øa,CN
7.14





Øz,CN
0.03















 








* Calculated here from experimental 1.5Xaa  = -6.27358(75) and 0.25(Xbb - Xcc) =  0.06078(20) MHz.

** Calculated here from the experimental nqcc's and the calculated Xab = 0.824(54) MHz (NOTE: The estimated uncertainity here is 2 × RMS).

 







 
 



Table 2.  o-Fluorobenzonitrile.  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
 H,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=1.38254615
 B2=1.38951103
 B3=1.3921311
 B4=1.38535487
 B5=1.39614208
 B6=1.42483906
 B7=1.15770802
 B8=1.33319536
 B9=1.08323363
 B10=1.08436902
 B11=1.08357011
 B12=1.08352047
 A1=118.75306821
 A2=120.64337167
 A3=120.00572088
 A4=121.87509574
 A5=120.6009877
 A6=151.83779231
 A7=118.8317922
 A8=119.16057584
 A9=119.33602335
 A10=120.20148774
 A11=120.97678113
 D1=0.
 D2=0.
 D3=0.
 D4=180.
 D5=180.
 D6=180.
 D7=180.
 D8=180.
 D9=180.
 D10=180.








 












Table 3.  o-Fluorobenzonitrile.  B3P86/6-31G(3d,3p) Rotational Constants (MHz), and B3LYP/cc-pVTZ Centrifugal Distortion Constants (kHz).
 




Calc
     Expt. [3]





A 2948.6
 2940.761152(88)

B 1520.6
 1512.700202(21)

C 1003.3
   998.652010(12)





Delta_J
 0.0389
 0.04051(15)

Delta_JK
 0.470
 0.50832(80)

Delta_K
 0.405
 0.4332(82)

delta_j
 0.0119
 0.012490(80)

delta_k
 0.278
 0.3018(10)






 








 








[1] O.Böttcher and D.H.Sutter, Z.Naturforsch. 43a,47(1988).

[2] O.Böttcher and D.H.Sutter, Z.Naturforsch. 41a,955(1986).

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

 








A.Dutta, A.I.Jaman, and R.N.Nandi, J.Mol.Spectrosc. 124,486(1987).

P.R.Varadwaj and A.I.Jaman, J.Mol.Spectrosc. 236,70(2006).

 








 








Benzonitrile Pentafluorobenzonitrile

m-Fluorobenzonitrile o-Tolunitrile

p-Fluorobenzonitrile m-Tolunitrile

2,3-Difluorobenzonitrile p-Tolunitrile

 








 








Table of Contents





Molecules/Nitrogen




 








 













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Last Modified 29 Sept 2015