CH2ClCH2CN
	Chlorine and Nitrogen
	Nuclear Quadrupole Coupling Constants
	in gauche 3-Chloropropionitrile
	Calculation of the chlorine and nitrogen nqcc tensors in the gauche conformer of 3-chloropropionitrile was made on a structure derived ab initio as discussed below.   These are presented in Tables 1 - 4.  Structure parameters are shown in Table 5, atomic coordinates in Table 6, and rotational constants in Table 7.
	The gauche confomer is higher in energy than the trans 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 gauche CH2ClCH2CN (MHz).     Calc. Expt.     35Cl Xaa   8.44 Xbb - 35.40 Xcc 26.96 Xab* 45.86 Xac* 16.31 Xbc* - 27.44   RSD 0.49 (1.1 %)   Xxx 36.37 Xyy 38.00 Xzz - 74.36 ETA 0.022 Øz,CCl 0.62
	* Algebraic signs of the the off-diagonal nqcc's correspond to the molecular a,b,c coordinates given below in Table 6.
	Table 2.  37Cl nqcc's in gauche CH2ClCH2CN (MHz).     Calc. Expt.     37Cl Xaa   5.92 Xbb - 27.27 Xcc 21.35 Xab* 36.52 Xac* 12.98 Xbc* - 21.38   RSD 0.44 (1.1 %)   Xxx 28.66 Xyy 29.94 Xzz - 58.61 ETA 0.022 Øz,CCl 0.62
	Table 3.  14N nqcc's in CH235ClCH2CN (MHz).     Calc. Expt.     14N Xaa - 0.510 Xbb - 1.382 Xcc 1.893 Xab* - 3.065 Xac* 0.905 Xbc* 0.863   RSD 0.030 (1.3 %)   Xxx 2.031 Xyy 2.262 Xzz - 4.293 ETA 0.054 Øz,CN 0.09
	* Here and in Table 4, algebraic signs of the the off-diagonal nqcc's correspond to the molecular a,b,c coordinates given below in Table 6.
	Table 4.  14N nqcc's in CH237ClCH2CN (MHz).     Calc. Expt.     14N Xaa - 0.453 Xbb - 1.439 Xcc 1.892 Xab* - 3.056 Xac* 0.899 Xbc* 0.874   RSD 0.030 (1.3 %)
	Molecular Structure
	The molecular structure was optimized at the MP2/6-311G(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. [1].   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. [2].  The CH bond lengths were corrected using r = 1.001 ropt, where ropt is obtained by MP2/6-31G(d,p) optimization [3].  Interatomic angles used in the calculation are those given by MP2/6-311+G(2d,p) optimization.
	Table 5.  gauche 3-Chloropropionitrile.  Heavy atom structure parameters (Å and degrees).  The complete structure is given here in Z-Matrix format.   NC(8) 1.1560 C(8)C(3) 1.4603 C(3)C(2) 1.5186 C(2)Cl 1.7744 NC(8)C(3) 179.06 C(8)C(3)C(2) 112.44 C(3)C(2)Cl 111.17
	Table 6.  gauche 3-Chloropropionitrile.  Atomic coordinates.  Normal species.   a (Å) b (Å) c (Å) Cl(1) 1.5206 - 0.5035 - 0.0770 C(2) 0.6152 0.9330 0.4380 C(3) - 0.6792 1.0747 - 0.3434 H(4) 1.2506 1.7985 0.2621 H(5) 0.4235 0.8329 1.5043 H(6) - 1.1569 2.0182 - 0.0675 H(7) - 0.4698 1.1063 - 1.4137 C(8) - 1.6148 - 0.0137 - 0.0740 N(9) - 2.3621 - 0.8656 0.1540
	Table 7.  gauche 3-Chloropropionitrile.  Rotational constants (MHz).  Normal species.   Calc. ropt    Expt. A 8196.9 B 2379.9 C 1969.2
	[1] J.Demaison, J.Cosléou, R.Bocquet, and A.G.Lesarri, J.Mol.Spectrosc. 167,400(1994).
	[2] I.Merke, L.Poteau, G.Wlodarczak, A.Bouddou, and J.Demaison, J.Mol.Spectrosc. 177,232(1996).
	[3] J.Demaison and G.Wlodarczak, Structural Chem. 5,57(1994).
	t-3-Chloropropionitrile			2-Chloropropionitrile
	Ethyl Cyanide			Chloroacetonitrile
	Ethyl Chloride
	Table of Contents
	Molecules/Chlorine
	Molecules/Nitrogen
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						Last Modified 2 July 2006