CF3CF2CH2Br
























 






Bromine


Nuclear Quadrupole Coupling Constants

in gauche-3-Bromo-1,1,1,2,2-Pentafluoropropane


 








 









Calculation of the Br nqcc's in gauche-3-bromo-1,1,1,2,2-pentafluoropropane was made here on a molecular structure (ropt) derived by MP2/6-311+G(3df,3pd) optimization, and on this same structure but with empirically corrected bond lengths (~ re) as described here.  Calculated nqcc's are given in Tables 1 and 2.  Structure parameters are given in Z-matrix format in Table 3, rotational constants in Table 4.


 








In Tables 1 and 2, subscripts a,b,c refer to the principal axes of the inertia tensor; x,y,z to the principal axes of the nqcc tensor.  ETA = (Xxx - Xyy)/Xzz.  (degrees) is the angle between its subscripted parameters.


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/TZV(3df,3p) model for calculation of the bromine efg's/nqcc's.

 








 
   








Table 1.  79Br nqcc's in g-CF3CF2CH2Br (MHz).  Calculation was made on the (1) ropt and (2) ~ re structures.
   










Calc. (1)

Calc. (2)
Expt.

   








Xaa
230.65
232.43


Xbb
- 58.13

- 59.20



Xcc - 172.52 - 173.22


Xab

371.99
372.48



Xac
268.63

269.16




Xbc
189.96

189.56




 







RMS





RSD
1.58 (0.39 %)
1.58 (0.39 %)



 







Xxx - 305.75 - 306.46



Xyy - 315.83 - 316.30



Xzz
621.58
622.76



ETA
0.0162
0.0158



z,CBr
1.41

1.40




 








 








 








   








Table 2.   81Br nqcc's in g-CF3CF2CH2Br (MHz).  Calculation was made on the (1) ropt and (2) ~ re structures.
   










Calc. (1)

Calc. (2)
Expt.

   








Xaa
193.56
195.04



Xbb
- 49.41

- 50.30




Xcc - 144.15 - 144.74



Xab
310.47
310.88



Xac
224.63

225.08




Xbc
158.39

158.06




 







RMS





RSD
1.38 (0.40 %)
1.38 (0.40 %)



 








 








 













Table 3.  g-CF3CF2CH2Br   MP2/6-311+G(3df,3pd) Structure Parameters ( and degrees).  Approximate equilibrium (~ re) bond lengths are given in parentheses.
 








 C             
 C,1,B1
 C,2,B2,1,A1
 H,3,B3,2,A2,1,D1,0
 H,3,B4,2,A3,1,D2,0
 Br,3,B5,2,A4,1,D3,0
 F,2,B6,2,A5,3,D4,0
 F,2,B7,1,A6,3,D5,0
 F,1,B8,2,A7,3,D6,0
 F,1,B9,2,A8,3,D7,0
 F,1,B10,2,A9,3,D8,0



   B1=1.54331146       (1.5401)
   B2=1.51243048
   B3=1.08577619
   B4=1.08446299
   B5=1.92066844        (1.9242)
   B6=1.34425986        (1.3428)
   B7=1.35703865        (1.3554)
   B8=1.32678675        (1.3257)
   B9=1.32496207        (1.3240)
   B10=1.33373370      (1.3325)
   A1=116.27063822
   A2=106.77264044
   A3=109.33122259
   A4=114.16512766
   A5=107.83249381
   A6=106.12278811
   A7=109.79170759
   A8=111.42101947
   A9=109.37219184
   D1=173.49511920
   D2=54.47082858
   D3=-67.36416342
   D4=-126.24363919
   D5=118.22303390
   D6=-167.61028693
   D7=72.00250004
   D8=-48.38558339






 













Table 4.  g-CF3CF2CH2Br   Rotational Constants (MHz).  79Br Species.







  ropt   ~ re   Expt.






A 1919.07
1924.4


B   732.6
  732.9


C   659.3
  659.8



 








 








F.E.Marshall, N.Moon, T.D.Persinger, D.J.Gillcrist, N.E.Shreve, W.C.Bailey, and G.S.Grubbs II, Abstract FB05, 72th International Symposium on Molecular Spectroscopy, Champaign-Urbana, 2017.

 








 








t-CF3CF2CH2Br CF3CF2Br CH3CH2Br


 








 








Table of Contents




Molecules/Bromine




 








 













gCF3CF2CH2Br.html






Last Modified 6 May 2017