HFC=O

















 













Deuterium


Nuclear Quadrupole Coupling Constants


in Formyl Fluoride


 








 








 








The deuterium nqcc tensor in formyl formyl fluoride was calculated on the substitution structure of Miller and Curl [1], and on an approximate equilibrium structure, ~re, given by MP2/aug-cc-pVTZ(G03) optimization with empirically corrected C-F and C=O bond lengths.  These are compared with the experimental nqcc's [2] in Table 1.  Structure parameters are shown in Table 2.

 








In Table 1, subscripts a,b,c refer to the principal axes of the inertia tensor; x,y,z to the principal axes of the nqcc tensor.  The nqcc y-axis is chosen coincident with the inertia c-axis, which is perpendicular to the molecular symmetry plane.  (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 for the B3LYP/6-31G(df,3p) model for calculation of the deuterium nqcc's. 

 








 








 
   








Table 1.  2H nqcc's in HFC=O (kHz).  Calculation was made on the rs and ~re molecular structures.
   










Calc / rs
Calc / ~re
Expt. [2]
   








Xaa
- 81.5
- 83.4



Xbb
167.2
171.7



Xcc
- 85.7
- 88.2



|Xab|
  22.9
  26.3



 







RMS







RSD
1.1 (0.86 %)
1.1 (0.86 %)



 







Xxx
- 83.6
- 86.1



Xyy
- 85.7
- 88.2



Xzz
169.3
174.4
205.2(40)


ETA
0.0123
0.0123
0 (assumed)


z,a
84.8
84.18



a,CH
84.9
84.14



z,CH
  0.1
  0.03



 








 








 








 


Table 2.  Formyl Fluoride molecular structure parameters rs [1] and ~re ( and degrees).
 




   rs   ~re





CH 1.095(10) 1.0902

C=O 1.181(5) 1.1761

CF 1.338(5) 1.3409

OCH 127.3(30) 128.12

OCF 122.8(5) 122.83


 








 








[1] R.F.Miller and R.F.Curl, J.Chem.Phys. 34,1847(1961). 

[2] S.G.Kukolich, J.Chem.Phys. 55,610(1971).

 








 








H2C=O HClC=O FClC=O


 








 








Table of Contents




Molecules/Deuterium




 








 













HFCO.html






Last Modified 21 Feb 2009