CH3C(=O)I

































 






Iodine


Nuclear Quadrupole Coupling Constants

in Acetyl Iodide


 








 








Calculation of the 127I nqcc tensor in acetyl iodide was made here on molecular structures given by MP2/6-311+G(d,p), MP2/6-311+G(2d,2p), and MP2/6-311G(3d,3p) optimizations; and on these same structures but with empirically corrected C-C, C=O, and CH bond lengths.  These nqcc's are compared with the experimental values in Tables 1 - 6.  Structure parameters are given in Table 7, rotational constants in Table 8.

 








In Tables 1 - 6, 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 (percent of the average of the magnitudes of the experimental nqcc's).  RSD is the calibration residual standard deviation of the B1LYP/6-311G(df,p) model for calculation of the efg's/nqcc's.


 








 








   








Table 1. 127I nqcc's in CH3C(=O)I (MHz).  

 







Calc (1) was made on the MP2/6-311+G(d,p) optimized molecular structure.

Calc (2) was made on this same structure but with empirically corrected C-C, C=O, and CH bond lengths.

 









Calc (1)
Calc (2)
  Expt. [1]
   








Xaa - 1586.5 - 1570.5 - 1563(2)

Xbb
  929.3
  919.7
  914(2)


Xcc
  657.2

  650.8
  649(3) *


Xab
- 135.6

- 132.2

- 135.6(2)


 







RMS
16.8 (1.62 %)
  5.5 (0.53 %)



RSD
15.2 (1.23 %)
15.2 (1.23 %)



 







Xxx
  936.6
  926.7



Xyy
  657.2
  650.8



Xzz - 1593.8 - 1577.5



ETA - 0.175 - 0.175



z,a
 3.08
 3.03



a,CI
 3.49
 3.52



z,CI
 0.41
 0.49



 
 






 








* Calculated here from zero-trace condition.  This note applies also to following Tables.


 









 









   








Table 2. 127I nqcc's in CH3C(=O)I (MHz).  

 







Calc (1) was made on the MP2/6-311+G(2d,2p) optimized molecular structure.

Calc (2) was made on this same structure but with empirically corrected C-C, C=O, and CH bond lengths.

 









Calc (1)
Calc (2)
  Expt. [1]
   








Xaa - 1583.5 - 1567.2 - 1563(2)

Xbb
  937.4
  927.3
  914(2)


Xcc
  646.1

  639.9
  649(3)


Xab
- 140.4

- 138.4

- 135.6(2)


 







RMS
18.0 (1.73 %)
  9.9 (0.95 %)



RSD
15.2 (1.23 %)
15.2 (1.23 %)



 







Xxx
  945.2
  935.0



Xyy
  646.1
  639.9



Xzz - 1591.3 - 1574.9



ETA - 0.188 - 0.187



z,a
 3.18
 3.17



a,CI
 3.50
 3.61



z,CI
 0.32
 0.44



 
 





   








 








   








Table 3. 127I nqcc's in CH3C(=O)I (MHz).  

 







Calc (1) was made on the MP2/6-311+G(3d,3p) optimized molecular structure.

Calc (2) was made on this same structure but with empirically corrected C-C, C=O, and CH bond lengths.

 









Calc (1)
Calc (2)
  Expt. [1]
   








Xaa - 1582.4 - 1568.4 - 1563(2)

Xbb
  930.5
  921.9
  914(2)


Xcc
  651.9

  646.5
  649(3)


Xab
- 137.0

- 135.0

- 135.6(2)


 







RMS
14.8 (1.42 %)
  5.7 (0.55 %)



RSD
15.2 (1.23 %)
15.2 (1.23 %)



 







Xxx
  938.0
  929.2



Xyy
  651.9
  646.5



Xzz - 1589.9 - 1575.7



ETA - 0.180 - 0.179



z,a
 3.11
 3.09



a,CI
 3.47
 3.54



z,CI
 0.35
 0.45



 
 






 








 








   








Table 4. 127I nqcc's in CD3C(=O)I (MHz).  

 







Calc (1) was made on the MP2/6-311+G(d,p) optimized molecular structure.

Calc (2) was made on this same structure but with empirically corrected C-C, C=O, and CH bond lengths.

 









Calc (1)
Calc (2)
  Expt. [1]
   








Xaa - 1565.5 - 1550.1 - 1541(3)

Xbb
  908.3
  899.4

  892(2)


Xcc
  657.2

  650.7
  649(4)


Xab
- 265.9

- 260.3

- 258.5(10)


 







RMS
17.6 (1.72 %)
  6.9 (0.67 %)



RSD
15.2 (1.23 %)
15.2 (1.23 %)



 
 


























   








Table 5. 127I nqcc's in CD3C(=O)I (MHz).  

 







Calc (1) was made on the MP2/6-311+G(2d,2p) optimized molecular structure.

Calc (2) was made on this same structure but with empirically corrected C-C, C=O, and CH bond lengths.

 









Calc (1)
Calc (2)
  Expt. [1]
   








Xaa - 1561.7 - 1545.8 - 1541(3)

Xbb
  915.6
  905.8

  892(2)


Xcc
  646.1

  639.9
  649(4)


Xab
- 272.6

- 268.7

- 258.5(10)


 







RMS
18.2 (1.77 %)
  9.9 (0.97 %)



RSD
15.2 (1.23 %)
15.2 (1.23 %)



 
 






 









 









   








Table 6. 127I nqcc's in CD3C(=O)I (MHz).  

 







Calc (1) was made on the MP2/6-311+G(3d,3p) optimized molecular structure.

Calc (2) was made on this same structure but with empirically corrected C-C, C=O, and CH bond lengths.

 









Calc (1)
Calc (2)
  Expt. [1]
   








Xaa - 1561.2 - 1547.6 - 1541(3)

Xbb
  909.3
  901.1

  892(2)


Xcc
  651.9

  646.5
  649(4)


Xab
- 267.6

- 263.9

- 258.5(10)


 







RMS
15.5 (1.51 %)
  6.6 (0.64 %)



RSD
15.2 (1.23 %)
15.2 (1.23 %)



 
 






 













Table 7.  Acetl Iodide.  Molecular structure parameters ( and degrees).  Corrected bond lengths are given in parentheses.
 



 H
 C,1,B1
 H,2,B2,1,A1
 H,2,B3,1,A2,3,D1,0
 C,2,B4,1,A3,3,D2,0
 O,5,B5,2,A4,1,D3,0
 I,5,B6,2,A5,1,D4,0






MP2/6-311+G(d,p)





 B1=1.09193128       (1.0889)
 B2=1.09220835       (1.0893)
 B3=1.09220835       (1.0893)
 B4=1.50385811       (1.4974)
 B5=1.18687532       (1.1781)
 B6=2.24269435
 A1=111.02564887
 A2=111.02564887
 A3=109.15022941
 A4=128.28750444
 A5=111.48333766
 D1=120.06005045
 D2=-119.96997477
 D3=0.
 D4=180.






MP2/6-311+G(2d,2p)





 B1=1.08497532       (1.0889)
 B2=1.08604823       (1.0893)
 B3=1.08604823       (1.0893)
 B4=1.49903188       (1.4974)
 B5=1.18870062       (1.1781)
 B6=2.20432012
 A1=110.88440346
 A2=110.88440346
 A3=109.43861989
 A4=127.31968145
 A5=111.97927556
 D1=119.43985928
 D2=-120.28007036
 D3=0.
 D4=180.






MP2/6-311+G(3d,3p)





 B1=1.08662869       (1.0889)
 B2=1.08760316       (1.0893)
 B3=1.08760316       (1.0893)
 B4=1.49974819       (1.4974)
 B5=1.18683553       (1.1781)
 B6=2.22896324
 A1=111.03643981
 A2=111.03643981
 A3=109.32558666
 A4=128.05942989
 A5=111.53997809
 D1=120.01132409
 D2=-119.99433795
 D3=0.
 D4=180.







 








 













Table 8.  CH3C(=O)I  Rotational constants (MHz).  
 




r (1) = MP2/6-311+G(d,p) opt

r (2) = r (1) with corrected C-C, C=O, and CH bond lengths.







  r (1)   r (2)    Expt. [1]






A  10041.
 10150.


B    2151.
   2155.


C    1791.
   1798.

 
 


r (1) = MP2/6-311+G(2d,2p) opt

r (2) = r (1) with corrected C-C, C=O, and CH bond lengths.






A  10143.
 10223.


B    2200.
   2204.


C    1828.
   1833.

 
 


r (1) = MP2/6-311+G(3d,3p) opt

r (2) = r (1) with corrected C-C, C=O, and CH bond lengths.






A  10092.
 10167.


B    2171.
   2174.


C    1807.
   1811.



 








 








[1] M.J.Moloney and L.C.Krisher, J.Chem.Phys. 45(9),3277(1966).


 









 








2-Iodopropene
t-1-Iodo-3,3,3-Trifluoropropane
tert-Butyl Iodide


 








 








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Molecules/Iodine




 








 













CH3COI.html






Last Modified 16 Jan 2017