CH2ClCH2CN

 








Chlorine and Nitrogen


Nuclear Quadrupole Coupling Constants

in trans 3-Chloropropionitrile


 







 
 
Calculation of the chlorine and nitrogen nqcc tensors in the trans (Cs) conformer of 3-chloropropionitrile was made on a structure derived ab initio as discussed below.   These are given in Tables 1 - 4.  Only Xaa for both 35Cl and 37Cl have been determined experimentally [1].  These are given in Tables 1 and 2.  Structure parameters are shown in Table 5, rotational constants in Table 6.
The trans confomer is lower in energy than the gauche conformer by about 1 kcal/mole as calculated at the B1LYP/TZV(3df,2p) and B3PW91/6-311+G(df,pd) levels of theory. 
 
In Tables 1 - 4, 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.  35Cl nqcc's in trans CH2ClCH2CN (MHz).
   










Calc.
Expt. [1]
   






35Cl Xaa - 61.35 - 58.8(9)
Xbb 23.81
Xcc 37.53
|Xab| 34.67
 
RSD 0.49 (1.1 %)
 
Xxx 36.14
Xyy 37.53
Xzz - 73.68
ETA 0.019
Øz,a 19.58
Øa,CCl 19.06
Øz,CCl   0.52
 
 
 
   







Table 2.  37Cl nqcc's in trans CH2ClCH2CN (MHz).
   










Calc.
Expt. [1]
   






37Cl Xaa - 48.36 - 47.6(8)
Xbb 18.78
Xcc 29.58
|Xab| 27.31
 
RSD 0.44 (1.1 %)
 
Xxx 28.48
Xyy 29.58
Xzz - 58.06
ETA 0.019
Øz,a 19.56
 
 
 
   







Table 3.  14N nqcc's in trans CH235ClCH2CN (MHz).
   










Calc.
Expt.
   






14N Xaa - 3.532
Xbb 1.507
Xcc 2.025
|Xab| 2.115
 
RSD 0.030 (1.3 %)
 
Xxx 2.277
Xyy 2.025
Xzz - 4.302
ETA - 0.058
Øz,a 20.00
Øa,CN 20.34
Øz,CN   0.34
 
 
 
   







Table 4.  14N nqcc's in trans CH237ClCH2CN (MHz).
   










Calc.
Expt.
   






14N Xaa - 3.533
Xbb 1.508
Xcc 2.025
|Xab| 2.114
 
RSD 0.030 (1.3 %)
 
 
 
Molecular Structure
 
The molecular structure was optimized at the MP2/6-311+G(d,p) level of theory.  The optimized C-C, C-C(N), and CN bond lengths were corrected using equations obtained from linear regression analyses of the data given in Tables VIII and IX of Ref. [2].   For the CCl bond, the structure was optimized at the MP2/6-311+G(2d,p) level and corrected by linear regression analysis of the data given in Table 4 of Ref. [3].  The CH bond lengths were corrected using r = 1.001 ropt, where ropt is obtained by MP2/6-31G(d,p) optimization [4].  Interatomic angles used in the calculation are those given by MP2/6-311+G(2d,p) optimization.
 
 
Table 5.  trans 3-Chloropropionitrile.  Heavy atom structure parameters (Å and degrees).  The complete structure is given here in Z-Matrix format.
 

NC(8) 1.1561
C(8)C(3) 1.4609
C(3)C(2) 1.5204
C(2)Cl 1.7757
NC(8)C(3) 178.45
C(8)C(3)C(2) 110.10
C(3)C(2)Cl 109.83
 
 
 
Table 6.  trans 3-Chloropropionitrile.  Rotational constants (MHz).  Normal species.
 
Calc. ropt    Expt. [1]
A 27 115.4 26 818.74(35.13)
B   1 518.2   1 508.89(1)
C   1 464.0   1 454.62(1)
 
 
[1] S.Xu and M.D.Harmony, J.Mol.Struct. 274,115(1992).
[2] J.Demaison, J.Cosléou, R.Bocquet, and A.G.Lesarri, J.Mol.Spectrosc. 167,400(1994).
[3] I.Merke, L.Poteau, G.Wlodarczak, A.Bouddou, and J.Demaison, J.Mol.Spectrosc. 177,232(1996).
[4] J.Demaison and G.Wlodarczak, Structural Chem. 5,57(1994).

 








 







g-3-Chloropropionitrile 2-Chloropropionitrile

Ethyl Cyanide Chloroacetonitrile
Ethyl Chloride
t-3-Bromopropionitrile
 

 








Table of Contents



Molecules/Chlorine
Molecules/Nitrogen
 

 













tCH2ClCH2CN.html






Last Modified 9 July 2006