CH3-CH2-CH2I




 









Iodine


Nuclear Quadrupole Coupling Constants

in gauche-1-Iodopropane

 








 

 




The 127I nqcc tensor in g-1-iodopropane was first determined by Niide et al. [1] in 1987, and revisited by Fujitake and Hayashi [2] in 1988.
 
Calculation of the nqcc tensor was made here on molecular structures given by MP2/6-311+G(d,p) and MP2/6-311+G(2d,p) optimizations; and on these same structures but with empirically corrected C-C and CH bond lengths.  These calculated nqcc's are compared with the experimental values [2] 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 (percentage 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.  
 

 







   






Table 1. 127I nqcc's in g-1-Iodopropane (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 and CH bond lengths.
 


Calc (1)
Calc (2)
Expt. [2]
   




Xaa - 1028.1 - 1031.4 - 1012.92(24)
Xbb   198.6   203.6   189.32(18)
Xcc   829.5   827.9   823.59(14)
|Xab| 1178.9  * 1174.7  * 1176.14(15)  *
|Xac|   355.3   354.4   361.67(75)
|Xbc|   235.0   233.3   245.43(288)
 
RMS 10.8 (1.60 %) 13.7 (2.03 %)
RSD 15.2 (1.23 %) 15.2 (1.23 %)
 
Xxx   924.3   923.0   923.88(250)
Xyy   887.9   886.2   881.28(205)
Xzz - 1812.2 - 1809.2 - 1805.16(56)
ETA - 0.0201 - 0.0203 - 0.0236(25)
Øz,a 32.49 32.37 32.77
Øz,b 59.13 59.25 58.93
Øz,c 99.15 99.13 99.42
Øz,CI   0.75   0.78
   
 
* The algabraic sign of the product XabXacXbc is negative.
 
 

   






Table 2. 127I nqcc's in g-1-Iodopropane (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 and CH bond lengths.
 


Calc (1)
Calc (2)
Expt. [2]
   




Xaa - 1016.9 - 1019.0 - 1012.92(24)
Xbb   194.8   197.3   189.32(18)
Xcc   822.1   821.7   823.59(14)
|Xab| 1171.6  * 1169.9 * 1176.14(15)  *
|Xac|   353.2   352.4   361.67(75)
|Xbc|   235.0   234.0   245.43(288)
 
RMS   4.0 (0.59 %)   5.9 (0.87 %)
RSD 15.2 (1.23 %) 15.2 (1.23 %)
 
Xxx   918.2   917.9   923.88(250)
Xyy   880.3   879.7   881.28(205)
Xzz - 1798.6 - 1797.6 - 1805.16(56)
ETA - 0.0211 - 0.0212 - 0.0236(25)
Øz,a 32.57 32.51 32.77
Øz,b 59.06 59.12 58.93
Øz,c 99.19 99.17 99.42
Øz,CI   0.73   0.74
   

   
* The algabraic sign of the product XabXacXbc is negative.
 
 
   






Table 3. 127I nqcc's in g-1-Iodopropane (MHz).  
 
Calc (1) was made on the MP2/6-311G(3df,3pd) optimized molecular structure.
Calc (2) was made on this same structure but with empirically corrected C-C and CH bond lengths.
 


Calc (1)
Calc (2)
Expt. [2]
   




Xaa - 993.3 - 994.6 - 1012.92(24)
Xbb   179.9   181.2   189.32(18)
Xcc   813.4   813.3   823.59(14)
|Xab| 1173.1  * 1172.6 * 1176.14(15)  *
|Xac|   357.2   357.2   361.67(75)
|Xbc|   240.5   240.3   245.43(288)
 
RMS 13.9 (2.05 %) 13.0 (1.93 %)
RSD 15.2 (1.23 %) 15.2 (1.23 %)
 
Xxx   914.2   914.4   923.88(250)
Xyy   875.3   875.1   881.28(205)
Xzz - 1789.5 - 1789.5 - 1805.16(56)
ETA - 0.0218 - 0.0219 - 0.0236(25)
Øz,a 32.99 32.96 32.77
Øz,b 58.70 58.73 58.93
Øz,c 99.39 99.38 99.42
Øz,CI   0.80   0.81
   
 
* The algabraic sign of the product XabXacXbc is negative.
 
Table 3.  g-1-Iodopropane.  Heavy atom structure parameters (Å and degrees).  
 
r (1) = MP2/6-311+G(d,p) opt
r (2) = r (1) with corrected C-C and CH bond lengths.
 
Point Group C1   r (1)   r (2)

IC(1) 2.1681 2.1681
C(1)C(2) 1.5226 1.5150
C(2)C(3) 1.5265 1.5187
IC(1)C(2) 113.24 113.24
C(1)C(2)C(3) 113.98 113.98
IC(1)C(2)C(3) - 65.93 - 65.93
 
r (1) = MP2/6-311+G(2d,p) opt
r (2) = r (1) with corrected C-C and CH bond lengths.
 
  r (1)   r (2)
IC(1) 2.1481 2.1481
Click on image to enlarge. C(1)C(2)
 1.5175 1.5150
C(2)C(3) 1.5237 1.5187
IC(1)C(2) 113.44 113.44
C(1)C(2)C(3) 113.87 113.87
IC(1)C(2)C(3) - 65.78 - 65.78
 
r (1) = MP2/6-311G(3df,3pd) opt
r (2) = r (1) with corrected C-C and CH bond lengths.
 
  r (1)   r (2)
IC(1) 2.1401 2.1401
C(1)C(2) 1.5168 1.5150
C(2)C(3) 1.5202 1.5187
IC(1)C(2) 112.78 112.78
C(1)C(2)C(3) 113.48 113.48
IC(1)C(2)C(3) - 65.71 - 65.71

 







 

Table 4.  g-1-Iodopropane.  Rotational constants (MHz).  
 
r (1) = MP2/6-311+G(d,p) opt
r (2) = r (1) with corrected C-C and CH bond lengths.
  r (1)   r (2) Expt. [2]

A 10 610.1 10 686.0 10 595.348(17)
B   1 767.8   1 775.0   1 781.651(2)
C   1 602.9   1 609.9   1 614.186(1)
   
r (1) = MP2/6-311+G(2d,p) opt
r (2) = r (1) with corrected C-C and CH bond lengths.
  r (1)   r (2) Expt. [2]
A 10 693.0 10 733.6 10 595.348(17)
B   1 789.4   1 792.2   1 781.651(2)
C   1 621.9   1 624.9   1 614.186(1)
 
r (1) = MP2/6-311G(3df,3pd) opt
r (2) = r (1) with corrected C-C and CH bond lengths.
  r (1)   r (2) Expt. [2]
A 10 671.7 10 678.1 10 595.348(17)
B   1 817.7   1 819.1   1 781.651(2)
C   1 645.1   1 646.4   1 614.186(1)

 
 
[1] Y.Niide, I.Ohkoshi, and M.Takano, J.Mol.Spectrosc. 122,113(1987).
[2] M.Fujitake and M.Hayashi, J.Mol.Spectrosc. 127,112(1988).
 
 
t-CH3CH2CH2I CH3I CH2ICl CH3CH2I
g-CH2ICH2F CH3-O-CH2I CH3CHICH3 (CH3)2CHCH2I

 








 








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Last Modified 15 Dec 2008