CH2FI







































Iodine



Nuclear Quadrupole Coupling Constants


in Fluoroiodomethane


 









 









Calculation of the 127I nqcc tensor in fluoroiodomethane 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 re CF and CH bond lengths.  These nqccs are compared with the experimental values [1,2] in Tables 1 - 6.  Structure parameters are given in Table 7, rotational constants in Table 8.


 









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.  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 uncertainty in the calculated nqcc's.


 









 









   







Table 1. 127I nqcc's in CH2FI (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 CF and CH bond lengths.

 









Calc (1)
Calc (2)
  Expt [1]
   







Xaa - 1580.7 - 1574.4 - 1581.6142(27)

Xbb
  591.2
  589.9
  584.1657(52)

Xcc
  989.4
  984.5
  997.4485(52)

|Xab|
  842.6
  838.7
  857.209(70)

 







RMS
  6.2 (0.59 %)
  9.2 (0.87 %)



RSD
15.2 (1.23 %)
15.2 (1.23 %)



 







Xxx
  879.8
  876.8
  882.383(44)  *

Xyy
  989.4
  984.5
  997.4485(52)

Xzz - 1869.2 - 1861.3 - 1879.832(44)

ETA
0.0686
0.0578
0.06121(2)

Øz,a
18.90
18.89
19.1825(11)

Øa,CI
18.57
18.46



Øz,CI
  0.33
  0.43



 
 







 









* Calculated here from the experimental  Xaa, Xbb, Xcc, and |Xab| using Kisiel's program QDIAG.  This note applies also to Tables 3 and 5.


 








 
   







Table 2. 127I nqcc's in CHDFI (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 CF and CH bond lengths.

 









Calc (1)
Calc (2)
  Expt [2]
   







Xaa - 1601.3 - 1594.8 - 1601.333(45) *

Xbb
  617.6
  616.1
  611.253(57) *

Xcc
  983.7
  978.8
  990.081(52) *

|Xab|
  808.3
  804.5
  820.57(47)
|Xac|   106.9   106.8   121.2(31)
|Xbc|     45.9     45.6     45.9(12)

 







RMS
  5.2 (0.49 %)
  8.0 (0.75 %)



RSD
15.2 (1.23 %)
15.2 (1.23 %)



 
 




 
* Calculated here from the experimental 1.5Xaa = -2402.000(68) and (Xbb - Xcc)/4 = -94.707(26) MHz with Kisiel's program QDIAG.  This note applies also to Tables 4 and 6.
 

 









   







Table 3. 127I nqcc's in CH2FI (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 CF and CH bond lengths.

 









Calc (1)
Calc (2)
  Expt [1]
   







Xaa - 1565.1 - 1557.2 - 1581.6142(27)

Xbb
  579.7
  578.3
  584.1657(52)

Xcc
  985.4
  978.9
  997.4485(52)

|Xab|
  843.6
  838.5
  857.209(70)

 







RMS
12.1 (1.15 %)
18.0 (1.71 %)



RSD
15.2 (1.23 %)
15.2 (1.23 %)



 







Xxx
  871.7
  868.2
  882.383(44)  *

Xyy
  985.4
  978.9
  997.4485(52)

Xzz - 1857.1 - 1847.1 - 1879.832(44)

ETA
0.0612
0.0600
0.06121(2)

Øz,a
19.10
19.07
19.1825(11)

Øa,CI
18.77
18.61



Øz,CI
  0.32
  0.46



 
 






   








 
   







Table 4. 127I nqcc's in CHDFI (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 CF and CH bond lengths.

 









Calc (1)
Calc (2)
  Expt [2]
   







Xaa - 1585.8 - 1577.8 - 1601.333(45) *

Xbb
  606.2
  604.7
  611.253(57) *

Xcc
  979.6
  973.1
  990.081(52) *

|Xab|
  809.6
  804.5
  820.57(47)
|Xac|   106.5   106.8   121.2(31)
|Xbc|     46.5     46.3     45.9(12)

 







RMS
11.2 (1.05 %)
17.2 (1.61 %)



RSD
15.2 (1.23 %)
15.2 (1.23 %)



 
 




 

 









   







Table 5. 127I nqcc's in CH2FI (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 CF and CH bond lengths.

 









Calc (1)
Calc (2)
  Expt [1]
   







Xaa - 1569.9 - 1562.7 - 1581.6142(27)

Xbb
  583.6
  582.5
  584.1657(52)

Xcc
  986.3
  980.2
  997.4485(52)

|Xab|
  843.2
  838.2
  857.209(70)

 







RMS
  9.3 (0.88 %)
14.8 (1.40 %)



RSD
15.2 (1.23 %)
15.2 (1.23 %)



 







Xxx
  874.5
  871.2
  882.383(44)  *

Xyy
  986.3
  980.2
  997.4485(52)

Xzz - 1860.8 - 1851.4 - 1879.832(44)

ETA
0.0601
0.0589
0.06121(2)

Øz,a
19.03
19.00
19.1825(11)

Øa,CI
18.72
18.55



Øz,CI
  0.32
  0.45



 
 







 








 
   







Table 6. 127I nqcc's in CHDFI (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 CF and CH bond lengths.

 









Calc (1)
Calc (2)
  Expt [2]
   







Xaa - 1590.5 - 1577.8 - 1601.333(45) *

Xbb
  609.8
  604.7
  611.253(57) *

Xcc
  980.7
  973.1
  990.081(52) *

|Xab|
  809.4
  804.5
  820.57(47)
|Xac|   106.0   106.8   121.2(31)
|Xbc|     46.0     46.3     45.9(12)

 







RMS
  7.7 (0.72 %)
13.8 (1.00 %)



RSD
15.2 (1.23 %)
15.2 (1.23 %)



 
 




 

 













Table 4.  CH2FI  Structure parameters (Å and degrees).
 



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

r (2) = r (1) with corrected CF and CH bond lengths.
 


Point Group CS
  r (1)   r (2)





CI 2.1559 2.1559
CH 1.0879 1.086
CF 1.3681 1.3598
HCI 107.44 107.44
FCI 110.88 110.88
HCH 112.54 112.54
 

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




  r (1)   r (2)



CI 2.1380 2.1380
CH 1.0858 1.086
CF 1.3714 1.3598
HCI 107.48 107.48
FCI 110.84 110.84
HCH 112.43 112.43
 


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

r (2) = r (1) with corrected CF and CH bond lengths.






  r (1)   r (2)





CI 2.1493 2.1493

CH 1.0821 1.086

CF 1.3715 1.3598

HCI 107.14 107.14

FCI 110.71 110.71

HCH 112.88 112.88



 









 














Table 5.  CH2FI Rotational constants (MHz).  
 




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

r (2) = r (1) with corrected CF and CH bond lengths.







  r (1)   r (2)       Expt [1]






A 38640.3 38959.1 38418.85846(14)

B   2835.3   2843.0   2875.248173(42)

C   2687.8   2696.2   2721.043224(41)
 
 


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

r (2) = r (1) with corrected CF and CH bond lengths.






A 38632.3 39026.6 38418.85846(14)

B   2869.9   2880.8   2875.248173(42)

C   2718.6   2730.4   2721.043224(41)
 
 


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

r (2) = r (1) with corrected CF and CH bond lengths.






A 38547.2 38882.0 38418.85846(14)

B   2851.2   2861.8   2875.248173(42)

C   2701.3   2712.8   2721.043224(41)



 









 









 









CH3I CHF2I CF3I



CH3Br CH2FBr CHF2Br CF3Br


CH3Cl CH2FCl CHF2Cl CF3Cl


 









 









[1] C.Puzzarini, G.Cazzoli, J.C.López, J.L.Alonso, A.Baldacci, A.Baldan, S.Stopkowicz, L.Cheng, and J.Gauss, J.Chem.Phys. 134,174312(2011); G.Cazzoli, A.Baldacci, A.Baldan, and C.Puzzarini, Mol.Phys. 109,2245(2011)


[2] C.Puzzarini, G.Cazzoli, J.C.López, J.L.Alonso, A.Baldacci, A.Baldan, S.Stopkowicz, L.Cheng, and J.Gauss, J.Chem.Phys. 137,024310(2012);  Iodine quadrupole coupling constants in CHDFI, CD2FI, and 13CH2FI.


 









 









Table of Contents





Molecules/Iodine





 









 














CH2FI.html






Last Modified 9 Dec 2012