CH2=CI-CH3
































 






Iodine


Nuclear Quadrupole Coupling Constants

in 2-Iodopropene

 








 








Calculation of the 127I nqcc tensor in 2-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 2-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 - 1831.8 - 1827.8 - 1820.783(33)

Xbb
  970.0
  967.4
  957.018(41)

Xcc
  861.8
  860.4
  863.765(40)

|Xab|
  143.2
  142.7
  147.5(10)

 







RMS
  9.9 (0.82 %)
  7.5 (0.62 %)



RSD
15.2 (1.23 %)
15.2 (1.23 %)



 







Xxx
  977.3
  974.6



Xyy
  861.8
  860.4



Xzz - 1839.1 - 1835.1



ETA - 0.0628 - 0.0622



Øz,a
 2.92
 2.91



Øa,CI
 2.92
 2.94



Øz,CI
 0.00
 0.03



 
 






 








 








   







Table 2. 127I nqcc's in 2-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 - 1811.7 - 1810.7 - 1820.783(33)

Xbb
  963.4
  962.7
  957.018(41)

Xcc
  848.3
  848.1
  863.765(40)

|Xab|
  145.9
  146.2
  147.5(10)

 







RMS
11.0 (0.90 %)
11.2 (0.93 %)



RSD
15.2 (1.23 %)
15.2 (1.23 %)



 







Xxx
  971.0
  970.3



Xyy
  848.3
  848.1



Xzz - 1819.4 - 1818.4



ETA - 0.0674 - 0.0672



Øz,a
 3.00
 3.01



Øa,CI
 2.96
 2.98



Øz,CI
 0.04
 0.03



 
 





   








 








   







Table 3. 127I nqcc's in 2-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 - 1822.2 - 1821.3 - 1820.783(33)

Xbb
  966.2
  965.3
  957.018(41)

Xcc
  856.0
  856.0
  863.765(40)

|Xab|
  141.9
  141.2
  147.5(10)

 







RMS
  7.0 (0.56 %)
  6.5 (0.54 %)



RSD
15.2 (1.23 %)
15.2 (1.23 %)



 







Xxx
  973.4
  972.5



Xyy
  856.0
  856.0



Xzz - 1829.4 - 1828.5



ETA - 0.0642 - 0.0637



Øz,a
 2.91
 2.91



Øa,CI
 2.92
 2.96



Øz,CI
 0.02
 0.05



 
 






 








 












Table 4.  2-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 CS
  r (1)   r (2)





IC(2) 2.1218 2.1218
C(2)-C(3) 1.5008 1.4946
C(2)=C(4) 1.3406 1.3315
IC(2)-C(3) 115.13 115.13
IC(2)=C(4) 119.82 119.82
 

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) 2.1015 2.1015
C(2)-C(3) 1.4951 1.4946
C(2)=C(4) 1.3339 1.3315
IC(2)-C(3) 115.14 115.14
IC(2)=C(4) 120.17 120.17
 


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) 2.1156 2.1156

C(2)-C(3) 1.4967 1.4946

C(2)=C(4) 1.3366 1.3315

IC(2)-C(3) 115.09 115.09

IC(2)=C(4) 119.77 119.77


 








 













Table 5.  2-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 9292.01 9388.04 9285.153(20)

B 2297.73 2302.69 2337.2198(14)

C 1863.56 1870.55 1887.5871(14)
 
 


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

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






A 9389.86 9410.00 9285.153(20)

B 2331.60 2332.56 2337.2198(14)

C 1889.64 1891.03 1887.5871(14)
 
 


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

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






A 9342.04 9381.34 9285.153(20)

B 2312.82 2314.68 2337.2198(14)

C 1875.29 1878.17 1887.5871(14)


 








 








[1] P.Groner and A.Bauder, J.Mol.Spectrosc. 74,259(1979).

 








J.Gripp and H.Dreizler, Z.Naturforsch. 49a,497(1994): Xaa = -1820.829(15) MHz, X_ = 93.247(23) MHz, |Xab| = 147.51(37) MHz.

 








 








2-Chloropropene 3-Chloropropene gauche 3-Chloropropene

2-Bromopropene
gauche 3-Bromopropene

 








 








Table of Contents




Molecules/Iodine




 








 













2IPropene.html






Last Modified 7 Oct 2009