C6H5F-d1




 






 









Deuterium


Nuclear Quadrupole Coupling Constants


in Fluorobenzene-d1


 








 








 


 





Deuterium nqcc's in monodeuterated fluorobenzene (2-, 3-, and 4-d1) were measured by Jans-Brli, M.Oldani, and A.Bauder [1].  Doraiswamy and Sharma [2] determined for fluorobenzene an ro molecular structure.

 








Calculation was made here of the deuterium nqcc's on the molecular structure of Doraiswamy and Sharma, and on a structure given by B3P86/6-31G(3d,3p) optimization.  In Tables 1 and 2, the calculated nqcc's are compared with the experimental values.  In Table 3, the principal values of the nqcc tensors calculated on the optimized structure are collected for easy comparison.  The structure parameters are compared in Table 4.  In Table 5, atomic coordinates for the optimized structure are given.

 








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

RMS is the overall root mean square difference between calculated and experimental inertia axes nqcc's (percentage of the average of the magnitudes of the experimental nqcc's).  RSD is the calibration residual standard deviation for the B3LYP/6-31G(df,3p) model for calculation of the nqcc's. 

 








 








   







Table 1.  Deuterium nqcc's in Fluorobenzene-d1 (kHz).  Calculation was made on the ro structure [2].
   










Calc.
Expt. [1]
   
 






 2H(4) Xaa
194.8
187.7(15)


Xbb
- 91.3
- 89.0(30)


Xcc - 103.6
- 98.7(25)

  ETA
0.063



   





 2H(3) Xaa
- 12.8
  - 9.6(33)


Xbb
113.4
112.6(32)

  Xcc - 100.5 - 103.0(26)

  |Xab|
125.4




 






Xxx
- 90.1
- 88.0 *

  Xyy - 100.5 - 103.0


Xzz
190.7
191.0


ETA
0.054
0.078


z,a
60.36
58.00


a,CD
60.43
60.43


z,CD
  0.07
  2.44


 





 2H(2) Xaa
  - 9.7
- 18.0(26)


Xbb
112.0
115.7(27)


Xcc - 102.3
- 97.7(22)


|Xab|
128.1




 






Xxx
- 90.7
- 95.6 *


Xyy - 102.3
- 97.7


Xzz
193.0
193.3


ETA
0.060
0.011


z,a
58.61
58.78


a,CD
58.33
58.33


z,CD
  0.28
  0.45


 






RMS
4.7 (5.1 %)




RSD
1.1 (0.9 %)




 






 








* Calculated here from the experimental diagonal nqcc's and the calculated value of Xab.

 








 








   







Table 2.  Deuterium nqcc's in Fluorobenzene-d1 (kHz).  Calculation was made on the B3P86/6-31G(3d,3p) ropt structure.
   










Calc.
Expt. [1]
   







 2H(4) Xaa
190.0
187.7(15)


Xbb
- 88.8
- 89.0(30)


Xcc - 101.1
- 98.7(25)

  ETA
0.065



 






 2H(3) Xaa
- 11.6
  - 9.6(33)


Xbb
111.2
112.6(32)

  Xcc
- 99.6 - 103.0(26)

  |Xab|
124.6




 






Xxx
- 89.2
- 87.3 *

  Xyy
- 99.6 - 103.0


Xzz
188.7
190.3


ETA
0.055
0.082


z,a
60.13
58.06


a,CD
60.17
60.17


z,CD
  0.03
  2.11


 





 2H(2) Xaa
  - 9.6
- 18.0(26)


Xbb
110.4
115.7(27)


Xcc - 100.8
- 97.7(22)


|Xab|
126.0




 






Xxx
- 89.2
- 93.8 *


Xyy - 100.8
- 97.7


Xzz
190.0
191.5


ETA
0.061
0.020


z,a
58.63
58.97


a,CD
58.34
58.34


z,CD
  0.29
  0.63


 






RMS
3.9 (4.2 %)




RSD
1.1 (0.9 %)




 






 








* Calculated here from the experimental diagonal nqcc's and the calculated value of Xab.

 








 








   






Table 3.  Principal values of the deuterium nqcc tensor calculated on the B3P86/6-31G(3d,3p) optimized structures of phenylacetylene (PhA), fluorobenzene (FB), and benzene.  (kHz and degrees)
   







  Xzz   Xyy   Xxx ETA z,CD
   





C6H5D 189.0   -99.9  -89.1 0.057   0

 





PhA D(4) 188.9   -99.7  -89.1 0.056   0

FB D(4) 190.0 -101.1  -88.8 0.065   0

 





PhA D(3) 188.8   -99.7  -89.0 0.057 0.01

FB D(3) 188.7   -99.6  -89.2 0.055 0.03

 





PhA D(2) 188.3   -99.8  -88.6 0.059 0.20

FB D(2) 190.0 -100.8  -89.2 0.061 0.29

 






 








The "bond bending" seen in D(2) compared with D(3) recalls that seen in chlorofluorobenzene (CFB).  In 1,3-CFB, z,CCl is 0.06o.  In 1,2-CFB, it is 1.07o.  Otherwise, the fluorine substituent has little - if any - effect on the deuterium coupling.

 








 







 




Table 4.  Fluorobenzene.  Molecular structure parameters ( and degrees).
 




 ro [2] ropt





C(1)F 1.354 1.3443

C(1)C(2) 1.385 1.3846

C(2)C(3) 1.396 1.3904

C(3)C(4) 1.398 1.3909

C(2)H(2) 1.081 1.0837

C(3)H(3) 1.083 1.0847

C(4)H(4) 1.080 1.0842

C(6)C(1)C(2) 123.2 122.47

C(1)C(2)C(3) 118.1 118.35

C(2)C(3)C(4) 120.5 120.48

C(3)C(4)C(5) 119.7 119.87

C(1)C(2)H(2) 119.9 119.57

C(2)C(3)H(3) 119.2 119.42



 








 




Table 5.  Fluorobenzene.  Atomic coordinates, ropt
 







 a ()
 b ()







F
2.1997
0

C(1)
0.8554
0

C(2,6)
0.1891 1.2137

C(3,5) - 1.2013 1.2038

C(4) - 1.8981
0

H(2,6)
0.7579 2.1361

H(3,5) - 1.7409 2.1447

H(4) - 2.9823
0


 








 








[1] S.Jans-Brli, M.Oldani, and A.Bauder, Mol.Phys. 68,1111(1989).

[2] S.Doraiswamy and S.D.Sharma, J.Mol.Struct. 102,81(1983).

 








Z.Kisiel, E.Białkowska-Jaworska, L.Pszczłkowski, J.Mol.Spectrosc. 232,47(2005):  ro and rm(1L) structures.

L.Nygaard, I.Bojesen, T.Pedersen, and J.Rastrup-Andersen, J.Mol.Struct. 2,209(1968): rs structure.

 








 








Benzene-d1 Phenylacetylene-d1 Pyridine-4D

1,2-Chlorofluorobenzene 1,3-Chlorofluorobenzene

 








 








Table of Contents




Molecules/Deuterium




 








 













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Last Modified 2 June 2003