CH3NHCl


















 





 








Chlorine and Nitrogen

Nuclear Quadrupole Coupling Constants

in N-Chloro-methylamine

 








 








 








Cl and N nqcc's in CH3NHCl, as well as all monodeuterated-methyl species, were determined by Caminati et al. [1.2].

 








Calculation of the chlorine and nitrogen nqcc tensors was made here on an ropt structure given by MP2/aug-cc-pVTZ(G03) optimization. These are compared with the experimental nqcc's in Tables 1 -3.  Structure parameters are compared with those of reference [2] in Table 4; rotational constants are given in Table 5.

 








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.

RMS is the root mean square difference between calculated and experimental nqcc's (percentage of the average experimental nqcc).  RSD is the residual standard deviation of calibration of the model for calculation of the nqcc's.

 








 








   






Table 1.  Cl and N nqcc's in CH3NH35Cl (MHz).  Calculation was made on the MP2/aug-cc-pVTZ(G03) optimized structure, ropt.
   









Calc.
Expt. [1]
   






35Cl Xaa - 66.82 - 67.02(6)


Xbb
18.78
18.90(7)


Xcc
48.04
48.12


|Xab|
56.55 *




|Xac|
  6.09




|Xbc|
  1.55



 







RMS
0.14 (0.32 %)




RSD
0.49 (1.1 %)



 







Xxx
46.11




Xyy
49.09




Xzz - 95.20




ETA
0.031




Øz,NCl
0.65



 






14N Xaa
4.856
4.63(9)


Xbb - 0.038 - 0.20(5)


Xcc - 4.818 - 4.43


|Xab|
1.874 *




|Xac|
0.201




|Xbc|
2.823



 







RMS
0.27   (8.9 %)




RSD
0.030 (1.3 %)



 







Xxx
0.668




Xyy
5.548




Xzz - 6.216




ETA
0.785




Øz,NCl
80.88




Øz,NH
60.06




Øz,NC
64.27



 







 








* The algebraic sign of the product XabXacXbc is negative.

 








 








   






Table 2.  Cl and N nqcc's in CH3NH37Cl (MHz).  Calculation was made on the MP2/aug-cc-pVTZ(G03) optimized structure, ropt.
   









Calc.
Expt. [1]
   






37Cl Xaa - 52.93 - 53.7(2)


Xbb
15.07
16.0(2)


Xcc
37.86
37.7


|Xab|
44.36 *




|Xac|
  4.79




|Xbc|
  1.20



 







RMS
0.7   (2.0 %)




RSD
0.44 (1.1 %)



 






14N Xaa
4.868
5.1(8)


Xbb - 0.050




Xcc - 4.818




|Xab|
1.859




|Xac|
0.191



  |Xbc|
2.825



 







RSD
0.030 (1.3 %)



 







 








* The algebraic sign of the product XabXacXbc is negative.

 








 








   






Table 3.  Cl and N nqcc's in CH2DNH35Cl (MHz).  Calculation was made on the MP2/aug-cc-pVTZ(G03) optimized structure, ropt.  See below for numbering of D atoms.
   









Calc.
Expt. [2]
   






D(5) Xaa(35Cl) - 67.35
 - 68.08(16)


Xbb
19.33
18.32(16)


Xaa(14N)
  4.87
  4.64(20)


Xbb
- 0.05
- 0.08(12)

 






D(6) Xaa(35Cl) -
 64.46
 -
 64.91(16)

  Xbb
16.60
14.78(15)


Xaa(14N)
  4.78
  4.53(19)


Xbb
  0.50
  0.25(11)

 






D(7) Xaa(35Cl) -
 64.11
 -
 64.78(11)


Xbb
16.09
15.78(12)


Xaa(14N)
  4.76
  4.42(18)


Xbb
- 0.49
- 1.01(12)

 







 








 








 


Table 3.  CH3NHCl  Selected structure parameters, ropt and ro [2] (Å and degrees).  The complete ropt structure is given here in Z-Matrix format.
 




  ropt    ro



ClN 1.7475 1.751(3)
NC 1.4639 1.467(6)
ClNC 108.88 109.32(17)
NH 1.0167 1.012(2)
Click on image to enlarge. ClNH 102.69 102.23(17)


 








 








 


Table 4.  CH3NHCl  Rotational constants (MHz).  Normal species.
 




Calc. ropt Expt. [1]





A 36 258.0 36 204.2(6)

B   5 992.0   5 935.8(2)

C   5 391.9   5 340.4(2)


 








 








[1] A.M.Mirri and W.Caminati, J.Mol.Spectrosc. 47,204(1973).

[2] W.Caminati, R.Cervellati, and A.M.Mirri J.Mol.Spectrosc. 51,288(1974).

 








 








CH3NH2 NH2Cl (CH3)2NH NF2H

 








 








Table of Contents




Molecules/Chlorine




Molecules/Nitrogen




 








 













CH3NHCl.html






Last Modified 12 May 2008