CF3COOH
		Deuterium
	Nuclear Quadrupole Coupling Constants
		in Trifluoroacetic Acid
	Antolinez et al. [1] measured the diagonal components of the deuterium nqcc tensor in the inertia axes system, and determined a partial substitution structure, a complete effective (ro) structure, and ab initio structures optimized at the HF/ and MP2/6-311++G** levels of theory.
	Calculation was made here of the deuterium nqcc's on the partial substitution structure combined with the effective CF3 parameters, on the effective structure, and on the MP2 optimized structure.  The calculated diagonal nqcc's are compared with the experimental values in Table 1.  The complete nqcc tensors in the principal axes of the nqcc tensor are given in Table 2. Structure parameters are compared in Table 3.
	The subscripts a,b,c refer to the principal axes of the inertia tensor,  the subscripts 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 plane of the molecule.  Ø (degrees) is the angle between its subscripted parameters. ETA = (Xxx - Xyy)/Xzz.
	Table 1.  Deuterium diagonal nqcc's in CF3COOD (kHz).  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).      Xaa    Xbb    Xcc    RMS     rs / ro 262.2 - 114.2 - 148.0 6.0 (3.5 %)    ro 255.9 - 110.4 - 145.5 5.6 (3.3 %) MP2 261.4 - 113.0 - 148.4 5.1 (3.0 %) Expt [1] 257.4(5) - 117.9(10) -139.5(10)
	Table 2.  Calculated deuterium nqcc's in CF3COOD (kHz).  Calculation was made on the indicated molecular structures.     rs / ro    ro MP2     Xaa 262.2 255.9 261.4 Xbb - 114.2 - 110.4 - 113.0 Xcc - 148.0 - 145.5 - 148.4 |Xab|  49.8   53.3   51.4   Xxx - 120.7 - 118.0 - 119.9 Xyy - 148.0 - 145.5 - 148.4 Xzz 268.7 263.5 268.3 ETA 0.102 0.104 0.106 Øz,a 7.41 7.68 8.11 Øa,OD 8.76 9.00 9.41 Øz,OD 1.35 1.32 1.30
	Table 3.  Molecular structure parameters (Å and degrees).     rs     ro   MP2 C-O 1.3215 1.3294 1.3390 OH 0.9684 0.9713 0.9690 CC 1.5225 1.5210 1.5420 C=O 1.2167 1.2219 1.2027 CF 1.3309 1.3273 CF* 1.3445 1.3391 HO-C 107.51 107.52 106.90 CC-O 110.81 110.90 109.38 CC=O 122.95 122.60 123.76 CCF 111.24 110.52 CCF* 111.01 110.28 O-CCF* ± 60.10 ± 59.83 F lies in plane of symmetry, the F* lie above and below this plane.  CF is cis with C=O.  OH is cis with C=O.
	[1] S.Antolinez, J.L.Alonso, H.Dreizler, E.Hentrop, and D.H.Sutter, Z.Naturforsch. 54a,524(1999).
	Benzoic Acid		HCOOD		CH3COOD
	Table of Contents
	Molecules/Deuterium
						CF3COOD.html
						Last Modified 20 Oct 2004