ClH2C-CF3						PDF
		Chlorine
	Nuclear Quadrupole Coupling Constants
	in 1-Chloro-2,2,2-Trifluoroethane
	Calculation of the chlorine nqcc's in 1-chloro-2,2,2-trifluoroethane was made on structures with bond lengths derived ab initio by the methods of the Lille group, as described below.  Interatomic angles used are those given by (1) MP2/6-311+G(d,p), and (2) B3P86/6-311+G(3d,3p) optimization.  Calculated nqcc's are shown in Tables 1 and 2.  Structure parameters are given in Z-Matrix format in Table 3.
	In Tables 1 and 2, 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 ClH2C-CF3 (MHz).  Calculation was made on the ab initio structure with interatomic angles given by (1) MP2/6-311+G(d,p), and (2) B3P86/6-311+G(3d,3p) optimization.     Calc. (1) Calc. (2) Expt.     Xaa - 46.06 - 47.47 Xbb   5.43   6.80 Xcc 40.63 40.67 |Xab| 52.36 51.46   Xxx 38.03 37.84 Xyy 40.63 40.67 Xzz - 78.66 - 78.51 ETA 0.033 0.036 Øz,a 31.90 31.10 Øa,CCl 32.32 31.85 Øz,CCl   0.42   0.75
	Table 2.  37Cl nqcc's in ClH2C-CF3 (MHz).  Calculation was made on the ab initio structure with interatomic angles given by (1) MP2/6-311+G(d,p), and (2) B3P86/6-311+G(3d,3p) optimization.     Calc. (1) Calc. (2) Expt.     Xaa - 38.11 - 37.45 Xbb   6.09   5.39 Xcc 32.02 32.05 |Xab| 40.32 40.54
	Molecular Structure
	The molecular structure was optimized at the MP2/6-311+G(d,p) level of theory assuming Cs symmetry.  The optimized CC single bond length was then corrected using the equation obtained from linear regression analysis of the data given in Table IX of Ref.[3].  Likewise, the optimized CF bond lengths were corrected by regression analysis of the data given in Table VI 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.[1].  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 (1) MP2/6-311+G(d,p) and (2) B3P86/6-311+G(3d,3p) optimization.
	Table 3. Structure parameters (Å and degrees).   Cl C 1 R1 C 2 R2 1 A1 F 3 R3 2 A3 1   D3 F 3 R3 2 A3 1 - D3 F 3 R4 2 A4 1 180. H 2 R5 3 A5 6   D5 H 2 R5 3 A5 6 - D5   MP2 Angles B3P86 Angles R1 1.7596 R2 1.5050 R3 1.3310 R4 1.3402 R5 1.087 A1 111.20 112.25 A3 112.18 112.47 A4 108.92 108.50 A5 108.25 108.51 D3   60.85   61.08 D5   59.83   59.80
	[1] I.Merke, L.Poteau, G.Wlodarczak, A.Bouddou, and J.Demaison, J.Mol.Spectrosc. 177,232(1996).
	[2] 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)
	[3] J.Demaison, J.Cosléou, R.Bocquet, and A.G.Lesarri, J.Mol.Spectrosc. 167,400(1994).
	[4] J.Demaison and G.Wlodarczak, Structural Chem. 5,57(1994).
	CH3Cl		CH3CH2Cl		CH2ClCHF2		CH3CCl3
	CF2ClCH3		CF2ClCHF2		CF2ClCH2F		CF2ClCF3
	CF3Cl		CH2ClCH2F
	Table of Contents
	Molecules/Chlorine
						CH2ClCF3.html
						Last Modified 14 August 2003