C6H5CCH-d1




 






 









Deuterium


Nuclear Quadrupole Coupling Constants


in Phenylacetylene-d1


 








 








 


 





Deuterium nqcc's were measured in phenylacetylene-d1 by Dreizler et al. [1], who also determined a number of experimental and theoretical molecular structures.

 








Calculation was made here of the deuterium nqcc's on the experimental rm(2) and theoretical CCSD(T)/cc-pVTZ molecular structures of  Ref. [1], and on a structure determined here by B3P86/6-31G(3d,3p) optimization.  In Tables 1 - 3, calculated nqcc's are compared with the experimental values.  In Table 4, the principal values of the nqcc tensors calculated on the B3P86 ropt structure are collected for easy comparison.  Structure parameters are compared in Table 5.

 








In Tables 1 - 3, subscripts a,b,c refer to the principal axes of the inertia tensor, 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 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 C6H5CCH-d1 (kHz).  Calculation was made on the rm(2) structure [1].
   










Calc.
Expt. [1]
   
 






2H(4) Xaa
194.8
188.9(10)


Xbb
- 92.1
- 92.2(35)


Xcc - 102.8
- 96.7(35)

   






RMS
4.9 (3.9 %)




 





2H(3) Xaa
- 15.8
- 28.7(21)


Xbb
117.6
117.9(32)

  Xcc - 101.7
- 89.2(32)

  |Xab|
125.3




 






RMS
10.4 (13.2 %)




 





2H(2) Xaa
- 19.3
- 31.7(15)

  Xbb
123.1
125.1(21)


Xcc - 103.8
- 93.5(21)


|Xab|
125.6




 






RMS
9.4 (11.2 %)




 





2H(8) * Xaa
226.4
207.6(10)


Xbb - 112.7 - 103.9(30)


Xcc - 113.7 - 103.7(30)


 






RMS
13.3 (9.6 %)




RSD
1.1 (0.9 %)




 






 








* Acetylenic.

 








 








   







Table 2.  Deuterium nqcc's in C6H5CCH-d1 (kHz).  Calculation was made on the CCSD(T)/cc-pVTZ structure [1].
   










Calc.
Expt. [1]
   
 






2H(4) Xaa
191.2
188.9(10)


Xbb
- 90.2
- 92.2(35)


Xcc - 100.9
- 96.7(35)

   






RMS
3.0 (2.4 %)




 





2H(3) Xaa
- 16.0
- 28.7(21)


Xbb
116.9
117.9(32)

  Xcc - 100.9
- 89.2(32)

  |Xab|
123.9




 






RMS
10.0 (12.7 %)




 





2H(2) Xaa
- 17.6
- 31.7(15)

  Xbb
118.2
125.1(21)


Xcc - 100.6
- 93.5(21)


|Xab|
122.1




 






RMS
9.9 (11.9 %)




 





2H(8) Xaa
214.7
207.6(10)


Xbb - 106.8 - 103.9(30)


Xcc - 107.8 - 103.7(30)


 






RMS
5.0 (3.6 %)




RSD
1.1 (0.9 %)




 






 








 








   







Table 3.  Deuterium nqcc's in C6H5CCH-d1 (kHz).  Calculation was made on the B3P86/6-31G(3d,3p) ropt structure.
   










Calc.
Expt. [1]
   







 2H(4) Xaa (zz)
188.9
188.9(10)


Xbb (xx)
- 89.1
- 92.2(35)


Xcc (yy)
- 99.7
- 96.7(35)

  ETA
0.056



   






RMS
2.5 (2.0 %)




 





 2H(3) Xaa
- 15.6
- 28.7(21)


Xbb
115.3
117.9(32)

  Xcc
- 99.7
- 89.2(32)

  |Xab|
122.5




 






RMS
9.8 (12.5 %)




 






Xxx
- 89.0



  Xyy
- 99.7




Xzz
188.8




ETA
0.057




z,a
59.06




a,CD
59.07




z,CD
  0.01




 





 2H(2) Xaa
- 17.5
- 31.7(15)


Xbb
117.3
125.1(21)


Xcc
- 99.8
- 93.5(21)


|Xab|
120.9




 






RMS
10.0 (12.0 %)




 






Xxx
- 88.6




Xyy
- 99.8




Xzz
188.3




ETA
0.059




z,a
59.56




a,CD
59.36




z,CD
  0.20




 





2H(8) Xaa (zz)
212.2
207.6(10)


Xbb (xx) - 105.6 - 103.9(30)


Xcc (yy) - 106.6 - 103.7(30)


ETA
0.005




 






RMS
3.3 (2.4 %)




RSD
1.1 (0.9 %)




 






 








 








   






Table 4.  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 substituent has little - if any - effect on the deuterium coupling.

 








 







 





Table 5.  Phenylacetylene.  Molecular structure parameters ( and degrees).
 





rm(2) *  ropt ** ropt ***






C(8)H(8) 1.0546 1.0635 1.0654

C(7)C(8) 1.2074 1.2136 1.2073

C(1)C(7) 1.4446 1.4372 1.4232

C(1)C(2) 1.3928 1.4044 1.4011

C(2)C(3) 1.3953 1.3946 1.3872

C(3)C(4) 1.3956 1.3976 1.3910

C(2)H(2) 1.0771 1.0826 1.0840

C(3)H(3) 1.0814 1.0829 1.0849

C(4)H(4) 1.0796 1.0828 1.0848

C(6)C(1)C(2) 120.70 119.45 119.15

C(1)C(2)C(3) 119.53 120.13 120.25

C(2)C(3)C(4) 120.22 120.21 120.25

C(3)C(4)C(5) 119.81 119.86 119.86

C(1)C(2)H(2) 120.19 119.27 119.14

C(2)C(3)H(3) 119.98 120.10 120.06

 



* Ref. [1], Table 12.  rm(2) mod IRLS.

** Ref. [1], Table 17.  CCSD(T)/cc-pVTZ optimized structure.

***  B3P86/6-31G(3d,3p) optimized structure.



 








 








[1] H.Driezler, H.D.Rudolph, and B.Hartke, J.Mol.Struct. 698,1(2004).

 








"Accurate Determination of the Deformation of the Benzene Ring upon Substitution:  Equilibrium Structures of Benzonitrile and Phenylacetylene"  H.D.Rudolph, J.Demaison, and A.G.Csszr, J.Phys.Chem. A 117(48),12969(2013).

 









 








Benzene-d1 Fluorobenzene-d1 Pyridine-4D

1,2-Chlorofluorobenzene 1,3-Chlorofluorobenzene

Acetylenes






 








 








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Molecules/Deuterium




 








 













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Last Modified 17 Jan 2005