CF3-CF2-CH2I




 









Iodine


Nuclear Quadrupole Coupling Constants

in trans-1-Iodo-2,2,3,3,3-pentafluoropropane

 








 

 




The 127I nqcc tensor in t-1-iodo-2,2,3,3,3-pentafluoropropane has been determined by Grubbs et al. [1].
 
Calculation of the 127I nqcc tensor in 1-Iodo-2,2,3,3,3-pentafluoropropane was made here on molecular structures given by MP2/6-311+G(d,p), MP2/6-311+G(2d,p), MP2/6-311+G(3d,3p), and MP2/6-311G(3df,3pd) optimizations; and on these same structures but with empirically corrected C-C, CF, and CH bond lengths.  These calculated nqcc's are given in Tables 1 - 4.  Structure parameters are given in Table 5, rotational constants in Table 6.
 
In Tables 1 - 4, 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 absolute experimental nqc'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 uncertainty in the calculated nqcc's.
 

 







   






Table 1. 127I nqcc's in t-1-Iodo-2,2,3,3,3-pentafluoropropane (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, CF, and CH bond lengths.
 


Calc (1)
Calc (2)
Expt [1]
   




Xaa - 1800.7 - 1797.1 - 1777.101(34)
Xbb   712.8   711.8   697.5618 *
Xcc 1087.9 1085.3 1079.5392(257)
|Xab|   975.9   974.0   984.685(33)
 
RMS 16.9 (1.43 %) 14.6 (1.23 %)
RSD 15.2 (1.23 %) 15.2 (1.23 %)
 
Xxx 1047.2 1045.6
Xyy 1087.9 1085.3
Xzz - 2135.1 - 2130.9
ETA 0.0191 0.0186
Øz,a 18.92 18.91
Øa,CI 20.14 20.11
Øz,CI   1.23   1.20
   
 
* Calculated here from zero trace condition of the nqcc tensor.  This note applies also to Tables 2 - 4.
 
 

   






Table 2. 127I nqcc's in t-1-Iodo-2,2,3,3,3-pentafluoropropane (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, CF, and CH bond lengths.
 


Calc (1)
Calc (2)
Expt [1]
   




Xaa - 1786.3 - 1780.8 - 1777.101(34)
Xbb   708.0   705.3   697.5618 *
Xcc 1078.2 1075.6 1079.5392(257)
|Xab|   962.5   961.3   984.685(33)
 
RMS   8.1 (0.68 %)   5.4 (0.46 %)
RSD 15.2 (1.23 %) 15.2 (1.23 %)
 
Xxx 1036.3 1033.6
Xyy 1078.2 1075.6
Xzz - 2114.5 - 2109.2
ETA 0.0198 0.0199
Øz,a 18.83 18.86
Øa,CI 20.06 20.07
Øz,CI   1.22   1.21
   

   
 
   






Table 3. 127I nqcc's in t-1-Iodo-2,2,3,3,3-trifluoropropane (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, CF, and CH bond lengths.
 


Calc (1)
Calc (2)
Expt [1]
   




Xaa - 1787.7 - 1782.7 - 1777.101(34)
Xbb   706.0   703.6   697.5618 *
Xcc 1081.8 1079.1 1079.5392(257)
|Xab|   973.7   972.7   984.685(33)
 
RMS   7.9 (0.69 %)   4.8 (0.40 %)
RSD 15.2 (1.23 %) 15.2 (1.23 %)
 
Xxx 1041.1 1038.9
Xyy 1081.8 1079.1
Xzz - 2122.9 - 2118.0
ETA 0.0191 0.0190
Øz,a 18.99 19.02
Øa,CI 20.20 20.20
Øz,CI   1.20   1.17
   
 
 
   






Table 4. 127I nqcc's in t-1-Iodo-2,2,3,3,3-trifluoropropane (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, CF, and CH bond lengths.
 


Calc (1)
Calc (2)
Expt [1]
   




Xaa - 1754.9 - 1755.5 - 1777.101(34)
Xbb   685.8   686.1   697.5618 *
Xcc 1069.1 1069.4 1079.5392(257)
|Xab|   977.8   978.6   984.685(33)
 
RMS 15.7 (1.32 %) 15.3 (1.29 %)
RSD 15.2 (1.23 %) 15.2 (1.23 %)
 
Xxx 1029.2 1029.9
Xyy 1069.1 1069.4
Xzz - 2098.3 - 2099.3
ETA 0.0190 0.0188
Øz,a 19.35 19.36
Øa,CI 20.40 20.39
Øz,CI   1.04   1.03
   
 
 
Table 5.  t-1-Iodo-2,2,3,3,3-pentafluoropropane.  Selected 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, CF, and CH bond lengths.
Point Group CS   r (1)   r (2)

IC(3) 2.1462 2.1462
C(3)C(2) 1.5110 1.5042
C(2)C(1) 1.5429 1.5340
C(1)F(6) 1.3291 1.3223
IC(3)C(2) 112.25 112.25
C(3)C(2)C(1) 111.96 111.96
C(2)C(1)F(6) 110.82 110.82
 
r (1) = MP2/6-311+G(2d,p) opt
r (2) = r (1) with corrected C-C, CF, and CH bond lengths.
  r (1)   r (2)
IC(3) 2.1250 2.1250
C(3)C(2) 1.5040 1.5042
C(2)C(1) 1.5371 1.5340
C(1)F(6) 1.3290 1.3223
IC(3)C(2) 112.49 112.49
C(3)C(2)C(1) 111.86 111.86
C(2)C(1)F(6) 110.83 110.83
 
r (1) = MP2/6-311+G(3d,3p) opt
r (2) = r (1) with corrected C-C, CF, and CH bond lengths.
  r (1)   r (2)
IC(3) 2.1381 2.1381
C(3)C(2) 1.5069 1.5042
C(2)C(1) 1.5406 1.5340
C(1)F(6) 1.3300 1.3223
IC(3)C(2) 112.01 112.01
C(3)C(2)C(1) 111.69 111.69
C(2)C(1)F(6) 110.80 110.80
 
r (1) = MP2/6-311G(3df,3pd) opt
r (2) = r (1) with corrected C-C, CF, and CH bond lengths.
  r (1)   r (2)
IC(3) 2.1194 2.1194
C(3)C(2) 1.5072 1.5042
C(2)C(1) 1.5391 1.5340
C(1)F(6) 1.3222 1.3223
IC(3)C(2) 111.67 111.67
C(3)C(2)C(1) 111.52 111.52
C(2)C(1)F(6) 110.67 110.67

 







 

Table 6.  t-1-Iodo-2,2,3,3,3-pentafluoropropane.  Rotational constants (MHz).  
 
r (1) = MP2/6-311+G(d,p) opt
r (2) = r (1) with corrected C-C, CF, and CH bond lengths.
  r (1)   r (2) Expt [1]

A 2529.4 2557.4
B   419.3   421.8
C   413.9   416.4
   
r (1) = MP2/6-311+G(2d,p) opt
r (2) = r (1) with corrected C-C, CF, and CH bond lengths.
  r (1)   r (2) Expt [1]
A 2527.3 2552.1
B   424.0   425.0
C   418.5   419.4
   
r (1) = MP2/6-311+G(3d,3p) opt
r (2) = r (1) with corrected C-C, CF, and CH bond lengths.
  r (1)   r (2) Expt [1]
A 2525.9 2554.4
B   422.2   424.1
C   416.8   418.6
 
r (1) = MP2/6-311G(3df,3pd) opt
r (2) = r (1) with corrected C-C, CF, and CH bond lengths.
  r (1)   r (2) Expt [1]
A 2552.0 2553.7
B   427.4   428.5
C   421.9   423.0

 
 
[1] G.S.Grubbs II, C.T.Dewberry, and S.A.Cooke, Abstract, 64th Ohio State University Symposium on Molecular Spectroscopy, June 22-26, 2009.
 
 
t-CH3CH2CH2I g-CH3CH2CH2I CH3I CH3CH2I
g-CH2ICH2F CH3-O-CH2I CH3CHICH3 (CH3)2CHCH2I
t-CF3CH2CH2I t-CF3CF2CF2I

 








 








Table of Contents



Molecules/Iodine

 








 













tCF3CF2CH2I.html






Last Modified 28 April 2009