CHF2Br PDF
 

 









Bromine


Nuclear Quadrupole Coupling Constants


in Bromodifluoromethane


 







 
 
Bromine nqcc's in bromodifluoromethane were determined by Ogata et al. [1], who also derived an effective ro molecular structure.   Calculation of the nqcc's was made here on this structure.  Calculated and experimental nqcc's are compared in Tables 1 and 2.  Structure parameters are given in Table 3.
 

 


 




In Tables 1 and 2, the subscripts a,b,c refer to the principal axes of the inertia tensor. Subscripts x,y,z refer to the principal axes of the nqcc tensor.  The nqcc y-axis is chosen coincident with the b-axis.  These are perpendicular to the symmetry plane of the molecule.  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 (percentage of average of absolute experimental nqcc's).  RSD is the residual standard deviation of the calibration of the computional model for calculation of the nqcc's.

 







 

   







Table 1.  Bromine nqcc's in CHF279Br (MHz).
   










Calc.
Expt. [1]
   






79Br Xaa 530.28 521.28(9)
Xbb - 282.62 - 279.80(6)
Xcc - 247.66 - 241.48
|Xac| 183.87 187.1(26)
 
RMS 6.58 (1.9 %)
RSD 1.58 (0.39 %)
 
Xxx - 288.93 - 284.9(23)
Xyy - 282.62 - 279.80(6)
Xzz 571.55 564.7(23)
ETA - 0.011 - 0.009(4)
Øz,a 12.6 13.1(3)
Øa,CBr 12.5 12.6(5)
Øz,CBr   0.1
 

 
 
 
   







Table 2.  Bromine nqcc's in CHF281Br (MHz).
   










Calc.
Expt. [1]
   






81Br Xaa 443.09 435.61(10)
Xbb - 236.12 - 233.84(6)
Xcc - 206.97 - 201.76
|Xac| 153.49 148.5(29)
 
RMS 5.42 (1.9 %)
RSD 1.38 (0.40 %)
 
Xxx - 241.39 - 234.6(25)
Xyy - 236.12 - 233.84(6)
Xzz 477.51 468.5(25)
ETA - 0.011 - 0.002(5)
Øz,a 12.6 12.5(4)
Øa,CBr 12.5 12.6(5)
Øz,CBr   0.1
 

 
 
Table 5. Structure parameters, ro [2] (Å and degrees).
CBr 1.908(15)
CF 1.347(11)
CH 1.098
BrCH 110.8
BrCF 110.6(8)
FCF 107.4(1)
Z-Matrix
H
C 1 R2
Br 2 R3 1 A3
F 2 R4 3 A4 1   D
F 2 R4 3 A4 1 - D
R2 = 1.098
R3 = 1.908
R4 = 1.347
A3 = 110.8
A4 = 110.6
D = 120.5735
 
 
[1] T.Ogata, S.Kuwano, and S.Oe, J.Mol.Spectrosc. 185,147(1997).
 

 








BrClCF2 CH3Cl CH3Br CF2Cl2

CHF2Cl CF3Cl CF3Br CH2Cl2
CH2FCl CH2Br2 BrClCH2
 

 








Table of Contents




Molecules/Bromine



 

 













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Last Modified 16 Dec 2004