ClF2C-CF3						PDF
		Chlorine
	Nuclear Quadrupole Coupling Constants
	in Chloropentafluoroethane
	Calculation of the chlorine nqcc's in chloropentafluoroethane were 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 ClF2C-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 - 25.90 - 26.71 Xbb - 12.78 - 12.03 Xcc 38.68 38.74 |Xab| 57.04 56.85   Xxx 38.07 37.95 Xyy 38.68 38.74 Xzz - 76.76 - 76.69 ETA 0.008 0.010 Øz,a 41.72 41.32 Øa,CCl 42.96 42.83 Øz,CCl   1.24   1.51
	Table 2.  37Cl nqcc's in ClF2C-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 - 22.32 - 22.93 Xbb - 8.16 - 7.60 Xcc 30.49 30.53 |Xab| 44.69 44.52
	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].  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. F 2 R5 3 A5 6   D5 F 2 R5 3 A5 6 - D5   MP2 Angles B3P86 Angles R1 1.7409 R2 1.5361 R3 1.3238 R4 1.3256 R5 1.3332 A1 111.15 111.54 A3 110.35 110.44 A4 109.09 109.00 A5 108.28 108.43 D3   60.39   60.48 D5   58.62   58.80
	[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).
	CH3Cl		CH3CH2Cl		CH2ClCHF2		CH3CCl3
	CF2ClCH3		CH2ClCH2F		CF2ClCH2F		CF2ClCHF2
	CF3Cl		CH2ClCF3
	Table of Contents
	Molecules/Chlorine
						CF2ClCF3.html
						Last Modified 14 August 2003