CH2Cl2





























 









Chlorine and Deuterium


Nuclear Quadrupole Coupling Constants


in Dichloromethane


 








 








35Cl nqcc's in dichloromethane (methylene chloride) were first measured by Myers and Gwinn [1], by Flygare and Gwinn [2], and revisited by Kisiel et al. [3]. Equilibrium structures were reported by Davis et al. [4], and Duncan [5].  The rmrho structure was derived by Berry and Harmony [6].  A semi-experimental equilibrium strcture reSE was derived by Vogt et al. [7].

 








Chlorine and deuterium nqcc's were calculated on each of the above structures.  These are compared with the experimental nqcc's [3] for chlorine in Tables 1 - 4.  Calculated deuterium nqcc's are given in Table 5.  The molecular structures are compared in Tables 6.

 

 





In Tables 1 - 4, subscripts a,b,c refer to principal axes of the inertia tensor; x,y,z to 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 for the B1LYP/TZV(3df,2p) model for calculation of the chlorine nqcc's. 

 







 








   






Table 1. Chlorine nqcc's in CH2Cl2 (MHz).  Calculation was made on the equilibrium structure of Davis et al. [4].
   









Calc.
Expt. [3]
   






35Cl Xaa - 41.94 - 41.7418(11)


Xbb
  1.87
  1.8004(12)


Xcc
40.07
39.9414(12)


Xab ± 51.38 ± 50.93(23)

 







RMS
0.14 (0.51 %)




RSD
0.49 (1.1 %)



 







 








 







 
   






Table 2. Chlorine nqcc's in CH2Cl2 (MHz).  Calculation was made on the equilibrium structure of Duncan et al. [5].
   









Calc.
Expt. [3]
   






35Cl Xaa - 41.88 - 41.7418(11)


Xbb
  1.81
  1.8004(12)


Xcc
40.06
39.9414(12)


Xab ± 51.35 ± 50.93(23)

 







RMS
0.10 (0.38 %)




RSD
0.49 (1.1 %)



 







Xxx
35.77
35.41(21)


Xyy
40.06
39.9414(12)


Xzz - 75.84 - 75.35(21)


ETA
0.057
0.060(3)


Øz,a
33.48
33.43(5)


Øa,CCl
34.02
34.11(2)


Øz,CCl
  0.54



 







 








The angle between principal z-axes is 1.08o larger than the ClCCl angle.  This is typical of the XCl2 dichloride moiety.

 








 








   






Table 3. Chlorine nqcc's in CH2Cl2 (MHz).  Calculation was made on the reSE structure of Vogt et al [7].
   









Calc.
Expt. [3]
   






35Cl Xaa - 42.08 - 41.7418(11)


Xbb
  1.99
  1.8004(12)


Xcc
40.09
39.9414(12)


Xab ± 51.10 ± 50.93(23)

 







RMS
0.24 (0.86 %)




RSD
0.49 (1.1 %)



 



























   






Table 4. Chlorine nqcc's in CH2Cl2 (MHz).  Calculation was made on the rmrho structure of Berry and Harmony [6].
   









Calc.
Expt. [3]
   






35Cl Xaa - 42.24 - 41.7418(11)


Xbb
  2.19
  1.8004(12)


Xcc
40.04
39.9414(12)


Xab ± 51.12 ± 50.93(23)

 







RMS
0.37 (1.3 %)




RSD
0.49 (1.1 %)



 







 








 








   







Table 5.  Deuterium nqcc's in CD2Cl2 (kHz).  Calculation was made on the molecular structures of Davis et al. [4],  Duncan [5], and Berry and Harmony [6].
   









Calc. [4]
Calc. [5]
Calc. [6]
   







Xaa
- 85.6
- 89.8
- 86.9

Xbb
  - 7.7
  - 9.1
  - 8.4

Xcc
  93.3
  98.9
  95.3

Xbc ± 126.4 ± 131.7 ± 127.9

 







Xxx
- 93.3
- 97.5
- 94.6

Xyy
- 85.6
- 89.8
- 86.9

Xzz
178.9
187.2
181.4

ETA - 0.043 - 0.041 - 0.042

Øz,b
55.89
56.14
56.04

Øb,CD
55.80
56.05
55.95

Øz,CD
 0.09
  0.09
  0.09

 







   








 














Table 6.  CH2Cl2 Molecular structure parameters (Å and degrees).








re [4] re [5] rmrho [6]reSE [7]







CCl 1.7648 1.766 1.76361.76425(3)

CH 1.0874 1.080 1.08511.0816(2)

ClCCl 112.03 111.96 112.25112.166(3)

HCH 111.51 112.10 111.90111.722(4)



 








 








[1] R.J.Myers and W.D.Gwinn, J.Chem.Phys. 20,1420(1952).

[2] W.H.Flygare and W.D.Gwinn, J.Chem.Phys. 36,787(1962).

[3] Z.Kisiel, J.Kosarzewski, and L.Pszczólkowski, Acta Physica Polonica A, 92,507(1997).

[4] R.W.Davis, A.G.Robiette, and M.C.L.Gerry, J.Mol.Spectrosc. 85,399(1981).

[5] J.L.Duncan, J.Mol.Struct. 158,169(1987).

[6] R.J.Berry and M.D.Harmony, Struct.Chem. 1,49(1989).

[7] N.Vogt, J.Demaison, and H.D.Rudolph, Mol.Phys. 112,2873(2014).

 








M.D.Harmony, S.N.Mathur, and S.J.Meridan, J.Mol.Spectrosc. 75,144(1979).  rs structure:  CCl = 1.767(2) Å, CH = 1.085(2) Å, HCH = 112.1(2)o, and ClCCl = 112.2(1)o

"Theoretical Investigation of the Nuclear Quadrupole Interaction of CH3Cl, CH2Cl2 and CHCl3" G.Frantz, H.Dufner, and P.C.Schmidt, Z.Naturforsch. 49a,116(1993).

 








 








CH3Cl CHCl3 CF2Cl2 CF3Cl

CD3F CD2F2 CDF3 CD2Br2

CD3CN CD2(CN)2 CH3D CD3Br

 








Calculation of Nuclear Quadrupole Coupling Constants on Approximate Equilibrium Structures of Chlorofluoromethanes.

 








 








Table of Contents




Molecules/Chlorine




Molecules/Deuterium




Summary/Methyls  Deuterium nqcc's in the substituted methanes.

 








 













CH2Cl2.html






Last Modified 5 July 2014