cis-ClHC=CHF

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Chlorine


Nuclear Quadrupole Coupling Constants

in cis-1-Chloro-2-Fluoroethylene


 








 








 








The complete chlorine nqcc tensor in cis-1-chloro-2-fluoroethylene was determined by Dore et al. [1].  Several molecular structure types were derived by Puzzarini et al. [2,3].

 








Calculation of the nqcc's was made here on the "empirical" equilibrium structure of ref. [2], and on the "recommended" equilibrium structure of ref. [3].  These are compared with the experimental nqcc's in Table 1.  Results of calculation made on the several structures of ref. [3] are summarized in Table 2.  "Empirical" and "recommended" equilibrium structure parameters are compared in Table 3.

 








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, these are 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 B1LYP/TZV(3df,2p) model for calculation of the chlorine nqcc's. 

 








 








 
   








Table 1. Chlorine nqcc's in c-ClHC=CHF (MHz).  Calculation was made on the "empirical" equilibrium structure of ref. [2], and the "recommended" equilibrium structure of ref. [3].
   










Calc. [2]

Calc. [3]
Expt. [1]
   








Xaa(35Cl) - 22.56 - 23.07 - 22.719(14)

Xbb
- 9.91
- 9.75 - 10.600(13)

Xcc
32.47
32.83
33.319(17)

|Xab|
57.53
57.60
57.4770(86)

 







RMS
0.63 (2.8 %)
0.60 (2.7 %)



RSD
0.49 (1.1 %)
0.49 (1.1 %)



 







Xxx
41.64
41.57
41.136(13)

Xyy
32.47
32.83
33.319(17)

Xzz - 74.11 - 74.40 - 74.455(13)

ETA - 0.124 - 0.1175 - 0.10499(29)

z,a
41.86
41.70
41.9909(47)

a,CCl
42.54
42.4



z,CCl
  0.68
  0.7



 
 





Xaa(37Cl) - 18.31
- 18.71 - 18.488(63)

Xbb
- 7.29
- 7.16
- 7.739(36)

Xcc
25.58
25.87
26.227(36)

|Xab|
45.28
45.33
45.403(86)

 







RMS
0.46 (2.6 %)
0.41 (2.4 %)



RSD
0.44 (1.1 %)
0.44 (1.1 %)



 








 








 









 


Table 2. The following molecular structure types of c-ClHC=CHF were derived by Puzzarini et al. [3].  For each, the RMS difference between calculated and experimental diagonal 35Cl nqcc's is given.

 



Structure Type RMS Difference

 


CCSD(T)/cc-pV(oo)Z 0.59 MHz (2.7 %)

Recommended re (See Table 1) 0.60 MHz (2.7 %)

Kraitchman's rs 1.78 MHz (8.0 %)

Typke's rss 1.79 MHz (8.1 %)

Watson's rm(2) 0.82 MHz (3.7 %)

 



 








 


Table 3.  Molecular structure parameters re [3] ( and degrees).
 




  re [2]    re [3]





C(1)Cl 1.7128(6) 1.715(2)

C(1)H 1.0776(4) 1.077(1)

C=C 1.3240(14) 1.325(1)

C(2)F 1.3317(3) 1.331(1)

C(2)H 1.0802(6) 1.079(1)

ClC(1)C(2) 123.07(1) 123.3(1)

HC(1)C(2) 120.74(9) 120.4(1)

FC(2)C(1) 122.61(6) 123.1(1)

HC(2)C(1) 123.50(2) 122.9(1)


 








 








[1] L.Dore, C.Puzzarini, G.Cazzoli, and A.Gambi, J.Mol.Spectrosc. 204,262(2000).

[2] C.Puzzarini, G.Cazzoli, A.Gambi, and J.Gauss, J.Chem.Phys. 125,054307(2006).

[3] C.Puzzarini, G.Cazzoli, L.Dore, and A.Gambi, Phys.Chem.Chem.Phys. 3,4189(2001).

 








J.L.Alonso, A.G.Lesarri, L.A.Leal, and J.C.Lpez, J.Mol.Spectrosc. 162,4(1993).


 









 








H2C=CHCl t-ClHC=CHF H2C=CCl2 cis-ClHC=CHCl

Calculation of NQCC's on Approximate Equilibrium Molecular Structures:  Ethylene.

 








 








Table of Contents




Molecules/Chlorine




 








 













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Last Modified 27 Oct 2007