CF3CF2CH2Br
























 






Bromine


Nuclear Quadrupole Coupling Constants

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

 








 








Bromine nqcc's in trans-3-bromo-1,1,1,2,2-pentafluoropropane were measured by Grubbs, et al. [1].

 








Calculation of the nqcc's 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 compared with the experimental values 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.  Ø (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 t-CF3CF2CH2Br (MHz).  Calculation was made on the (1) ropt and (2) ~ re structures.
   









Calc. (1)
Calc. (2)
Expt. [1]
   







Xaa
515.42
515.70
510.0486(56)

Xbb -
 195.26 -
 195.09 -
 191.8570(48)

Xcc - 320.16 - 320.61 -
 318.1916(48)

|Xab|
297.32
298.19
300.0703(12)

 







RMS
3.83 (1.12 %)
 4.01 (1.18 %)


RSD
1.58 (0.39 %)
1.58 (0.39 %)



 







Xxx - 303.24 - 303.62 -
 302.6509(44)

Xyy - 320.16 - 320.61 -
 318.1916(48)

Xzz
623.40
624.23
620.8425(50)

ETA
0.0271
0.0272
0.02503(1)

Øz,a
19.96
20.00
20.26

Øa,CBr
21.09
21.13



Øz,CBr
  1.13
  1.13



 








 








 








   







Table 2.   81Br nqcc's in t-CF3CF2CH2Br (MHz).  Calculation was made on the (1) ropt and (2) ~ re structures.
   









Calc. (1)
Calc. (2)
Expt. [1]
   







Xaa
430.28
430.52
425.7699(63)

Xbb -
 162.80 -
 162.66 -
 159.9335(53)

Xcc - 267.48 - 267.86 -
 265.8364(53)

|Xab|
248.80
249.53
251.0690(15)

 







RMS
3.23 (1.14 %)
 3.37 (1.19 %)


RSD
1.38 (0.40 %)
1.38 (0.40 %)



 








 








 













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








 C
 C,1,R1
 C,2,R2,1,A3
 F,2,R3,1,A4,3,-D3,0
 F,2,R3,1,A4,3,D3,0
 F,1,R4,2,A1,3,180.,0
 F,1,R5,2,A2,3,-D1,0
 F,1,R5,2,A2,3,D1,0
 Br,3,R6,2,A6,6,180.,0
 H,3,R7,2,A7,6,-D2,0
 H,3,R7,2,A7,6,D2,0



 R1=1.5419647         (1.5389)
 R2=1.51027734       (1.5135)
 R3=1.34673326       (1.3453)
 R4=1.32336783       (1.3224)
 R5=1.33228374       (1.3311)
 R6=1.92068858       (1.9242)
 R7=1.08490966
 A3=111.52137369
 A4=107.06177945
 A1=110.67668017
 A2=109.93005633
 A6=111.01573292
 A7=109.48130176
 D1=-59.67742157
 D2=-60.59678133
 D3=121.99247093






 













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







  ropt   ~ re   Expt. [1]






A 2541.0
 2544.7
 2536.196013(122)

B   566.1
   565.6
   561.655997(50)

C   556.0
   555.5
   551.651919(50)


 








 








[1] F.E.Marshall, N.Moon, T.D.Persinger, D.J.Gillcrist, N.E.Shreve, W.C.Bailey, and G.S.Grubbs II, Mol.Phys. 117,1351(2019).

 








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.

N.Force, D.J.Gillcrist, C.C.Hurley, F.E.Marshall, N.A.Payton, T.D.Persinger, N.E.Shreve, and G.S.Grubbs II, Abstract TE05, 69th International Symposium on Molecular Spectroscopy, Champaign-Urbana, 2014.

 








 








g-CF3CF2CH2Br
 CF3CF2Br CH3CH2Br


 








 








Table of Contents




Molecules/Bromine




 








 













tCF3CF2CH2Br.html






Last Modified 1 June 2019