CHCl2-CH2Cl















 









Chlorine


Nuclear Quadrupole Coupling Constants

in 1,1,2-Trichloroethane

 








 








 

 





Calculation of the 35Cl nuclear quadrupole coupling constants in CHCl2CH2Cl was made here on ropt   molecular structures given by MP2/6-311+G(3df,3pd) and MP2/aug-cc-pVTZ optimization, each with approximate equilibrium bond lengths.  These nqcc's are given in Tables 1 - 3.  Structure parameters are given in Table 4, equilibrium rotational constants and dipole moments in Table 5, quartic centrifugal distortion constants in Table 6.

 








A PE scan at MP2/6-311+G(d,p) level of theory has identified two stable conformers as shown below:

 








gauche, C1

trans, Cs



























 








At MP2/aug-cc-pVTZ opt level of theory, Egauche < Etrans by 5.7 kJ/mol.  Results of calculations made on the gauche conformer are given below - for the trans conformer, click here.

 








In Tables 1 - 3, subscripts a,b,c refer to the principal axes of the inertia tensor; subscripts x,y,z to the principal axes of the nqcc tensor.  Ø (degrees) is the angle between its subscripted parameters.  ETA = (Xxx - Xyy)/Xzz.

RSD is the calibration residual standard deviation of the B1LYP/TZV(3df,2p) model for calculation of the efg's/nqcc's.

 








 








   







Table 1.  Cl(3) nqcc's in g-CH35Cl2-CH235Cl (MHz).  Calculation was made on the (1) MP2/6-311+G(3df,3pd) and (2) MP2/aug-cc-pVTZ ropt structures, each with approximate equilibrium bond lengths.  Atomic numbering is shown above.
   









Calc. (1)
Calc. (2)
Expt.
   







Xaa -
 50.78
 -
 50.71



Xbb
17.10
17.17



Xcc
33.68
33.54



Xab -
 41.69
 -
 41.60



Xac
19.94
20.05



Xbc
  9.39
  9.43



 







RSD
0.49 (1.1 %) 0.49 (1.1 %)


 







Xxx
36.91
36.91



Xyy
38.15
38.08



Xzz -
 75.07
 -
 74.99



ETA
0.0165
0.0155



Øz,CCl
0.59
0.57



 








 








 








   







Table 2.  Cl(4) nqcc's in g-CH35Cl2-CH235Cl (MHz).  Calculation was made on the (1) MP2/6-311+G(3df,3pd) and (2) MP2/aug-cc-pVTZ ropt structures, each with approximate equilibrium bond lengths.  Atomic numbering is shown above.
   









Calc. (1)
Calc. (2)
Expt.
   







Xaa
32.37
32.46



Xbb -
 42.38
 -
 42.01



Xcc
10.01
  9.55



Xab
23.35
23.14



Xac -
 15.09
 -
 15.11



Xbc
46.25
46.53



 







RSD
0.49 (1.1 %) 0.49 (1.1 %)


 







Xxx
36.46
36.46



Xyy
39.97
39.96



Xzz -
 76.43
 -
 76.42



ETA
0.0460
0.0458



Øz,CCl
0.45
0.44



 








 








 








   







Table 3.  Cl(8) nqcc's in g-CH35Cl2-CH235Cl (MHz).  Calculation was made on the (1) MP2/6-311+G(3df,3pd) and (2) MP2/aug-cc-pVTZ ropt structures, each with approximate equilibrium bond lengths.  Atomic numbering is shown above.
   









Calc. (1)
Calc. (2)
Expt.
   







Xaa -
 57.80
 -
 57.49



Xbb
28.97
28.88



Xcc
20.84
28.61



Xab -
 29.52
 -
 29.55



Xac
26.95
27.21



Xbc
  9.93
10.04



 







RSD
0.49 (1.1 %) 0.49 (1.1 %)


 







Xxx
35.78
35.75



Xyy
39.05
39.00



Xzz -
 74.83
 -
 74.75



ETA
00438
0.0435



Øz,CCl
0.50
0.47



 








 







 
 




Table 4.  g-CH35Cl2-CH235Cl.  Optimized structure parameters (Å and degrees).  Approximate re bond lengths are shown in parentheses.  Atomic numbering is shown above.
 












 C
 C,1,B1
 Cl,1,B2,2,A1
 Cl,1,B3,2,A2,3,D1,0
 H,1,B4,2,A3,3,D2,0
 H,2,B5,1,A4,5,D3,0
 H,2,B6,1,A5,5,D4,0
 Cl,2,B7,1,A6,5,D5,0








  MP2/6-311+G(3df,3pd)    MP2/aug-cc-pVTZ







 B1=1.51357225    (1.5118)
 B2=1.77030705    (1.7747)
 B3=1.76173855    (1.7661)
 B4=1.08493238
 B5=1.08618866
 B6=1.0860905
 B7=1.76782315    (1.7722)
 A1=107.93382045
 A2=111.48839422
 A3=111.41793984
 A4=110.00984745
 A5=108.96935886
 A6=110.88553832
 D1=121.90318935
 D2=-117.95069532
 D3=174.87073922
 D4=-64.20875913
 D5=54.45566473
  B1=1.51250061     (1.5108)
 B2=1.77821383     (1.7750)
 B3=1.76880495     (1.7656)
 B4=1.08528611
 B5=1.08686204
 B6=1.08682508
 B7=1.77619037     (1.7729)
 A1=107.76259566
 A2=111.46430842
 A3=111.91486718
 A4=110.24086254
 A5=109.20614035
 A6=110.57851272
 D1=121.53473358
 D2=-118.06325033
 D3=174.43457983
 D4=-64.21307424
 D5=54.28251035









 








 



Table 5.  g-CH35Cl2-CH235Cl.  Rotational Constants (MHz) and Dipole Moments (D).
 




r (1) = MP2/6-311+G(3df,3pd) ropt with approximate re bond lengths.

r (2) = MP2/aug-cc-pVTZ ropt with approximate re bond lengths.
 




  Calc. r (1) Calc. r (2)    Expt.






A 3588.9
 3592.6

B 1487.4
 1490.2

C 1088.3
 1090.4

 



|µa| *
 0.10
 0.10

|µb| *
 1.22
 1.22

|µc| *
 0.12
 0.12

*  B1LYP/TZV(3df,2p) on r(1) and r(2) structures.


 








 














Table 6.  g-CH35Cl2-CH235Cl.  B3LYP/cc-pVTZ Quartic Centrifugal Distortion Constants (kHz).
 





Delta_J
 0.112
 D_J
0.0756

Delta_JK 1.58
 D_JK
1.79

Delta_K 1.02
 D_K
0.844

delta_J 0.0244
 d_1
 -
 0.0244

delta_K 0.818
 d_2
 -
 0.0181









 








1,1,2-Trichlorotrifluoroethane
 Chlorofluoroethanes
 t-1,1,2-Trichloroethane

 








 








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Molecules/Chlorine




 








 













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Last Modified 11 Nov 2013