H2C=CFCl						PDF
		Chlorine
	Nuclear Quadrupole Coupling Constants
		in 1-Chloro-1-fluoroethylene
	Calculation of the chlorine nqcc's in 1-chloro-1-fluoroethylene was made on a structure derived ab initio, as described below.  These are compared with the experimental nqcc's of Alonso et al. [1] in Table 1.  Structure parameters are given in Table 2.
	Complete chlorine nqcc tensors in 1-chloro-1-fluoroethylene have been determined by Leung et al., which authors also determined substitution and effective molecular structures.  The results of calculation on these structures are given here.
	In Table 1, 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. Chlorine nqcc's in H2C=CFCl (MHz).  Calculation was made on the ab initio ropt structure.     Calc. Expt. [1]     35Cl Xaa - 72.94 - 72.92(4) Xbb 39.26 38.63(3) Xcc 33.68 34.30(4) |Xab|   6.30   RMS 0.51 (1.0 %) RSD 0.49 (1.1 %)   Xxx 39.61 Xyy 33.68 Xzz - 73.30 ETA - 0.081 Øz,a 3.20 Øa,CCl 3.16 Øz,CCl 0.04     37Cl Xaa - 57.48 - 57.52(5) Xbb 30.93 30.50(4) Xcc 26.55 27.02(4) |Xab|   5.06   RMS 0.37 (0.96 %) RSD 0.44 (1.1 %)
	Ab Initio Molecular Structure
	The molecular structure was optimized at the MP2/6-311+G(d,p) level of theory assuming Cs symmetry.  The optimized C=C bond length was then corrected using the equation obtained from linear regression analysis of the data given in Table IX of Ref. [4].  Likewise, the optimized CF bond length was corrected by regression analysis of the data given in Table VI of Ref. [3], and the CCl bond 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 [5].  Interatomic angles are those given by MP2/6-311+G(d,p) optimization.
	Table 2.  Molecular structure parameters, ropt (Å and degrees).        Hc and Ht are with respect to Cl C(1)Cl 1.7106 C(1)F 1.3287 C=C 1.3230 C(2)Hc 1.0764 C(2)Ht 1.0786 C=CCl 125.89 ClCF 112.04 C=CHc 120.08 C=CHt 119.26
	[1] J.L.Alonso, A.G.Lesarri, L.A.Leal, and J.C.López, J.Mol.Spectrosc. 162,4(1993).
	[2] I.Merke, L.Poteau, G.Wlodarczak, A.Bouddou, and J.Demaison, J.Mol.Spectrosc. 177,232(1996).
	[3] R.M.Villamañan, W.D.Chen, G.Wlodarczak, J.Demaison, A.G.Lesarri, J.C.López, and J.L.Alonso, J.Mol.Spectrosc. 171,223(1995).
	[4] J.Demaison, J.Cosléou, R.Bocquet, and A.G.Lesarri, J.Mol.Spectrosc. 167,400(1994).
	[5] J.Demaison and G.Wlodarczak, Structural Chem. 5,57(1994).
	R.G.Stone and W.H.Flygare, J.Mol.Spectrosc. 32,233(1969).  Xaa = -73.04(10), Xbb = 38.60(10), and Xcc = 34.44(20) MHz for 35Cl.
	H2C=CHCl		c-FHC=CHCl		H2C=CCl2
	F2C=CFCl		c-ClHC=CHCl
	Table of Contents
	Molecules/Chlorine
						CH2CFCl.html
						Last Modified 13 Feb 2006