CH2=CH-CH2I
































 






Iodine


Nuclear Quadrupole Coupling Constants

in gauche 3-Iodopropene

 








 








Calculation of the 127I nqcc tensor in gauche 3-iodopropene was made here on molecular structures given by MP2/6-311+G(d,p), MP2/6-311+G(2d,p), and MP2/6-311G(3d,3p) optimizations; and on these same structures but with empirically corrected C-C, C=C, and CH bond lengths.  These nqcc's are compared with the experimental values in Tables 1 - 3.  Structure parameters are given in Table 4, rotational constants in Table 5.

 








In Tables 1 - 3, subscripts a,b,c refer to the principal axes of the inertia tensor; x,y,z to the principal axes of the nqcc tensor.  Ø (degrees) is the angle between its subscripted parameters.  ETA = (Xxx - Xyy)/Xzz.

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 nqcc's, which may be taken as an estimate of the uncertainties in the calculated nqcc's (uncertainties in the optimized molecular structures notwithstanding).

 








 








   







Table 1. 127I nqcc's in gauche 3-Iodopropene (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=C, and CH bond lengths.

 









Calc (1)
Calc (2)
  Expt. [1]
   







Xaa - 1300.8 - 1301.3 - 1337(12)

Xbb
  377.3
  378.8
  387(6)

Xcc
  923.5
  922.5
  950(9)

|Xab|
1137.1 *
1134.4 *
1081(4)

|Xac|
  100.3
    98.5



|Xbc|
    72.7
    71.4



 







RMS
26 (3.0 %)
26 (3.0 %)



RSD
15.2 (1.23 %)
15.2 (1.23 %)



 







Xxx
  962.8
  961.4



Xyy
  917.4
  916.5



Xzz - 1880.2 - 1878.0



ETA - 0.0241 - 0.0239



Øz,CI
 0.38
 0.40



 
 






 








* The algebraic sign of the product XabXacXbc is negative.

 








 








   







Table 2. 127I nqcc's in gauche 3-Iodopropene (MHz).  

 







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

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

 









Calc (1)
Calc (2)
  Expt. [1]
   







Xaa - 1297.1 - 1297.3 - 1337(12)

Xbb
  379.0
  379.4
  387(6)

Xcc
  918.1
  918.0
  950(9)

|Xab|
1126.6 *
1125.8 *
1081(4)

|Xac|
    93.4
    92.4



|Xbc|
    69.9
    69.3



 







RMS
30 (3.3 %)
30 (3.3 %)



RSD
15.2 (1.23 %)
15.2 (1.23 %)



 







Xxx
  957.3
  956.9



Xyy
  910.6
  910.4



Xzz - 1867.9 - 1867.3



ETA - 0.0250 - 0.0249



Øz,CI
 0.32
 0.33



 
 





   








* The algebraic sign of the product XabXacXbc is negative.

 








 








   







Table 3. 127I nqcc's in gauche 3-Iodopropene (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=C, and CH bond lengths.

 









Calc (1)
Calc (2)
  Expt. [1]
   







Xaa - 1289.9 - 1290.7 - 1337(12)

Xbb
  372.5
  372.8
  387(6)

Xcc
  917.4
  917.9
  950(9)

|Xab|
1132.1 *
1132.0 *
1081(4)

|Xac|
  100.1
    98.1



|Xbc|
    73.4
    72.2



 







RMS
34 (3.8 %)
34 (3.8 %)



RSD
15.2 (1.23 %)
15.2 (1.23 %)



 







Xxx
  957.6
  957.6



Xyy
  911.0
  911.3



Xzz - 1868.6 - 1868.8



ETA - 0.0249 - 0.0248



Øz,CI
 0.36
 0.36



 
 






 








* The algebraic sign of the product XabXacXbc is negative.

 








 












Table 4.  gauche 3-Iodopropene.  Heavy atom structure parameters (Å and degrees).  Complete structures are given here in Z-matrix representation.
 



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

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


Point Group C1
  r (1)   r (2)





IC 2.1785 2.1785
C-C 1.4885 1.4830
C=C 1.3423 1.3331
IC-C 111.14 111.14
C-C=C 123.00 123.00
C=C-CI 114.53 114.53
 

r (1) = MP2/6-311+G(2d,p) opt
r (2) = r (1) with corrected C-C, C=C, and CH bond lengths.




  r (1)   r (2)



IC 2.1581 1.1581
C-C 1.4841 1.4830
C=C 1.3369 1.3331
IC-C 111.46 111.46
C-C=C 123.17 123.17
C=C-CI 114.81 114.81
 


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

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






  r (1)   r (2)





IC 2.1735 2.1735

C-C 1.4839 1.4830

C=C 1.3391 1.3331

IC-C 110.89 110.89

C-C=C 123.10 123.10

C=C-CI 114.17 114.17


 








 













Table 5.   gauche 3-Iodopropene.  Rotational constants (MHz).  
 




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

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







  r (1)   r (2)  Expt. [1]






A 17750.88 17864.91 17644.34(25)

B   1567.50   1574.03   1588.12(1)

C   1521.72   1527.98   1538.64(1)
 
 


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

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






A 18044.00 18083.37 17644.34(25)

B   1582.11   1584.22   1588.12(1)

C   1536.80   1538.79   1538.64(1)
 
 


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

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






A 17746.64 17769.37 17644.34(25)

B   1581.10   1583.65   1588.12(1)

C   1533.80   1536.26   1538.64(1)


 








 








[1] Y.Sasada, Y.Niide, M.Takano, and T.Satoh, J.Mol.Spectrosc. 66,421(1977).

 








I.Ohkoshi, Y.Niide, M.Takano, and Y.Sasada, J.Mol.Spectrosc. 82,27(1980):  |Xab| = 1160(5) MHz

 








 








2-Iodopropene cis-3-Iodopropene





2-Chloropropene 3-Chloropropene gauche 3-Chloropropene

2-Bromopropene
gauche 3-Bromopropene

 








 








Table of Contents




Molecules/Iodine




 








 













g3IPropene.html






Last Modified 8 Oct 2009