CHFClCF2-O-CF2H



 








 








 









Chlorine


Nuclear Quadrupole Coupling Constants

in 2-Chloro-1,1,2-trifluoroethyl-difluoromethyl ether

 
(aka Enflurane)



 








 

 





Complete nqcc tensors for both 35Cl and 37Cl in each of three structural conformers of 2-chloro-1,1,2-trifluoroethyl-difluoromethyl ether (Enflurane) have been calculated on PBE1PBE/6-311+G(3d,3p) optimized molecular structures.  (This particular optimization was chosen based on its success for calculation of Cl nqcc tensors in 2-chloroethyl ethyl sulfide.)

 








The conformers of enflurane considered here are shown below:

 








Enflurane T
Enflurane G+
Enflurane G-

 








 
































 








Calculated and experimental [1] nqcc tensors for Enflurane G- are compared below in Tables 1 and 2. Structure parameters are given in Table 3, rotational constants and dipole moments in Table 4.  (For T and G+, click on the above figure headings.)

 








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 the principal z-axis of the nqcc tensor and the CCl bond axis.

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,2p) model for calculation of the chlorine efg's/nqcc's.

 








 








   






Table 1.  35Cl nqcc's in Enflurane, G- (MHz).  Calculation was made on the PBE1PBE/6-311+G(3d,3p) optimized structure.
   





 


Calc
Expt [1]
   






35Cl Xaa
23.37
23.9679(43)
 
Xbb - 58.28 -
 58.6093(58)


Xcc
34.91
34.6415(101)


Xab - 35.05
33.919(72) *


Xac
- 9.07
  8.82(29) *


Xbc - 21.90
21.847(95) *

   






RMS
0.42 (1.1 %)




RSD
0.49 (1.1 %)




 






Xxx
36.15




Xyy
40.16


 
Xzz - 76.31




ETA
0.053




Øz,CCl
1.48


   







 








* Absolute value.











 








   






Table 2.  37Cl nqcc's in Enflurane, G- (MHz).  Calculation was made on the PBE1PBE/6-311+G(3d,3p) optimized structure.
   





 


Calc
Expt [1]
   






37Cl Xaa
17.69
18.2100 (73)
 
Xbb - 45.06 -
 45.3488(99)


Xcc
27.38
27.1388(172)


Xab - 28.42
27.67(14) *


Xac
- 7.49
  7.41(55) *


Xbc - 17.45
17.30(19) *

 







RMS
0.37 (1.2 %)




RSD
0.44 (1.1 %)



 







Xxx
28.49




Xyy
31.65


 
Xzz - 60.14




ETA
0.053




Øz,CCl
1.49


   







 








* Absolute value.

 







 
 
  


Table 3.   Enflurane, G-.  Selected structure parameters (Å and degrees).  Complete structure is given here in Z-matrix format.

 







C(1)O 1.3848

OC(4) 1.3597

C(4)C(5) 1.5330

C(5)Cl 1.7544

C(1)OC(4) 116.90

OC(4)C(5) 108.58

C(4)C(5)Cl 111.39

OC(4)C(5)Cl   62.85












 








 








 



Table 4.  35Cl-Enflurane, G-.  Rotational constants (MHz) and dipole moments (D).
 



 

Calc      Expt [1]







A 1860.7 1857.35494(28)


B   725.8   722.78593(18)


C   604.9   605.95878(16)


 



|µa|   0.06


|µb|   0.22


|µc|   0.19


 








 








[1] C.Pérez, E.Caballero-Mancebo, A.Lesarri, E.J.Cocinero, I.Alkorta, R.D.Suenram, J.-U.Grabow, and B.H.Pate, Chem.Euro.J. 22(28),9804(2016).





















Enflurane T
 2-Chloroethyl ethyl sulfide Chloromethyl methyl ether

Enflurane G+ Chloromethyl Ethyl Ether Isoflurane

 








 








Table of Contents




Molecules/Chlorine




 








 













Enflurane_III.html






Last Modified 8 June 2016