(CH3)2C=CHCl						PDF
		Chlorine
	Nuclear Quadrupole Coupling Constants
		in 1-Chloro-2-Methylpropene
	Calculation of the chlorine nqcc's in 1-chloro-2-methylpropene was made on a molecular structure derived ab initio, as described below. These are compared with the experimental nqcc's [1] in Tables 1 and 2.   Structure parameters are given in Z-matrix format in Table 3.  Rotational constants, calculated and experimental, are compared in Table 4.
	In Tables 1 and 2, 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.
	Subscripts a,b,c refer to the principal axes of the inertia tensor; x,y,z to the principal axes of the nqcc tensor.  The nqcc y-axis is chosen coincident with the inertia c-axis, these are perpendicular to the molecular symmetry plane.  Ø (degrees) is the angle between its subscripted parameters.  ETA = (Xxx - Xyy)/Xzz.
	Table 1.  35Cl nqcc's in 1-Chloro-2-Methylpropene (MHz).     Calc. Expt. [1]     35Cl Xaa - 53.01 - 52.591(1) Xbb 21.64 21.086(2) Xcc 31.37 31.505(1) |Xab| 38.76 39.037(99)   RMS 0.41 (1.2 %) RSD 0.49 (1.1 %)   Xxx 38.12 37.922(73) Xyy 31.37 31.505(2) Xzz - 69.49 - 69.427(72) ETA - 0.097 - 0.092 Øz,a 23.04 23.330(37) Øa,CCl 23.76 23.76 * Øz,CCl   0.72   0.43 *
	* Calculated here corresponding to the structure given below.
	Table 2.  37Cl nqcc's in 1-Chloro-2-Methylpropene (MHz).     Calc. Expt. [1]     37Cl Xaa - 41.75 - 41.429(3) Xbb 17.03 16.595(3) Xcc 24.72 24.833(4) |Xab| 30.57 30.659(31)   RMS 0.32 (1.2 %) RSD 0.44 (1.1 %)   Xxx 30.04 29.793(26) Xyy 24.72 24.833(4) Xzz - 54.77 - 54.626(26) ETA - 0.097 - 0.092 Øz,a 23.06 23.290(16) Øa,CCl 23.78 23.78 * Øz,CCl   0.72   0.49 *
	* Calculated here corresponding to the structure given below.
	Molecular Structure
	The molecular structure was optimized at the MP2/6-311+G(d,p) level of theory assuming Cs symmetry.  The optimized CC bond lengths, single and double,  were corrected using equations obtained from linear regression analysis of the data given in Table 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(d,p) optimization.
	Table 3.  Z-Matrix (Å and degrees).   C C 1 R1 C 2 R2 1 A3 C 2 R3 1 A4 3 180. H 4 R4 2 A8 3 180. Cl 4 R5 2 A9 3     0. H 1 R6 2 A1 3 180. H 1 R7 2 A2 3 - D1 H 1 R7 2 A2 3   D1 H 3 R8 2 A6 6     0. H 3 R9 2 A7 6 - D2 H 3 R9 2 A7 6   D2   R1 = 1.500 A3 = 116.28 R2 = 1.495 A4 = 119.03 R3 = 1.334 A1 = 111.89 R4 = 1.081 A2 = 110.32 R5 = 1.729 A6 = 112.26 R6 = 1.090 A7 = 109.93 R7 = 1.092 A8 = 122.43 R8 = 1.087 A9 = 124.69 R9 = 1.092 D1 = - 59.17 D2 = 121.12
	Table 4.  Rotational Constants (MHz).  35Cl species.   Calc. ropt    Expt. [1] A 8 451.7 8 400.0178(5) B 2 260.7 2 257.7687(2) C 1 823.7 1 818.7071(2)
	[1] T.Bruhn and W.Stahl, J.Mol.Spectrosc. 202,272(2000).
	[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).
	H2C=CHCl			H2C=CFCl			c-ClHC=CHCl
	c-FHC=CHCl			t-FHC=CHCl			H2C=CCl2
	H2C=CClCN			F2C=CHCl			F2C=CCl2
	CH3ClC=CH2			Cl2C=CHCl			F2C=CFCl
	c-CH3HC=CHCl			t-CH3HC=CHCl			CH2ClHC=CH2
	c-CH3FC=CHCl
	Table of Contents
	Molecules/Chlorine
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						Last Modified 26 Oct 2003