Trifluorothiazole
	Nitrogen and Sulfur
	Nuclear Quadrupole Coupling Constants
		in Trifluorothiazole
	Calculation of nitrogen and sulfur nqcc's in trifluorothiazole was made a molecular structure obtained by B3PW91/6-31G(2d,2pd) optimization.  These calculated nqcc's are given in Tables 1 - 4.  Structure parameters are given in Table 5, atomic coordinates in Table 6, and rotational constants in Table 7.
	In Tables 1 and 4, subscripts a,b,c refer to the principal axes of the inertia tensor, 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.  RSD is the residual standard deviation of calibration of the model for calculation of the nqcc's.
	Table 1. Nitrogen nqcc's in Trifluorothiazole-32S (MHz).  Calculation was made on the B3PW91/6-31G(2d,2pd) ropt structure.     Calc. Expt.     14N Xaa 1.765 Xbb - 3.268 Xcc 1.503 |Xab| 1.080   RSD 0.030 (1.3 %)   Xxx 1.987 Xyy 1.503 Xzz - 3.490 ETA - 0.139 Øz,a 78.38 Øa,bi 75.58 Øz,bi*   2.80
	* The z-axis makes an angle of 2.80o with the external bisector ( 'bi' ) of the C(2)N(3)C(4) and tilts toward C(4).
	Table 2. Nitrogen nqcc's in Trifluorothiazole-33S (MHz).  Calculation was made on the B3PW91/6-31G(2d,2pd) ropt structure.     Calc. Expt.     14N Xaa 1.777 Xbb - 3.280 Xcc 1.503 |Xab| 1.051   RSD 0.030 (1.3 %)
	Table 3. Nitrogen nqcc's in Trifluorothiazole-34S (MHz).  Calculation was made on the B3PW91/6-31G(2d,2pd) ropt structure.     Calc. Expt.     14N Xaa 1.789 Xbb - 3.292 Xcc 1.503 |Xab| 1.022   RSD 0.030 (1.3 %)
	Table 4.  33S nqcc's in  Trifluorothiazole (MHz).  Calculation was made on the B3PW91/6-31G(2d,2pd) ropt structure. Calc. [a] B3LYP/6-311G(3df,3p) Model. Calc. [b] B3LYP/TZV+(3df,3p) Model.     Calc. [a] Calc. [b] Expt.     Xaa - 26.91 - 27.23 Xbb - 2.84 - 2.68 Xcc 29.75 29.91 |Xab| 10.64 10.84   RSD 0.39 (1.7 %) 0.35 (1.5 %)   Xxx   1.19   1.42 Xyy 29.75 29.91 Xzz - 30.94 - 31.33 ETA 0.923 0.909 Øx,a 69.27 69.27 Øa,bi 68.36 68.36 Øx,bi*   0.90   0.91
	* The x-axis makes an angle of 0.90o / 0.91o with the external bisector ( 'bi' ) of the C(5)S(1)C(2) and tilts toward C(5).
	Table 5.   Trifluorothiazole and Thiazole.  Structure parameters, ropt (Å and degrees).   X = F X = H S(1)C(2) 1.7353 1.7313 C(2)N(3) 1.2807 1.2988 N(3)C(4) 1.3630 1.3690 C(4)C(5) 1.3554 1.3635 C(5)S(1) 1.7471 1.7187 C(2)X(2) 1.3114 1.0818 C(4)X(4) 1.3168 1.0818 C(5)X(5) 1.3176 1.0781 C(5)S(1)C(2)   86.52   89.03 S(1)C(2)N(3) 117.90 115.14 C(2)N(3)C(4) 109.13 110.28 N(3)C(4)C(5) 116.45 116.09 C(4)C(5)S(1) 110.00 109.46 S(1)C(2)X(2) 118.59 120.56 N(3)C(4)X(4) 118.86 119.18 C(4)C(5)X(5) 128.56 129.10
	Table 6.  Trifluorothiazole-32S.  Atomic coordinates, ropt     a (Å)   b (Å) S(1) - 0.6587 - 1.2939 C(2) - 1.3075 0.3156 N(3) - 0.4818 1.2946 C(4) 0.7906 0.8058 C(5) 0.9190 - 0.5435 F(2) - 2.6101 0.4671 F(4) 1.7973 1.6545 F(5) 2.0225 - 1.2634
	Table 7.  Trifluorothiazole-32S.  Rotational Constants (MHz).   Calc. ropt A  2871.5 B  1560.8 C  1011.2
	Thiazole			2-Fluorothiazole			4-Fluorothiazole
	2-Methylthiazole			4-Methylthiazole			5-Methylthiazole
	1,2,4-Thiadiazole			1,2,5-Thiadiazole			1,3,4-Thiadiazole
	Pyrazole			Imidazole			Oxazole
	Table of Contents
	Molecules/Nitrogen
	Molecules/Sulfur
						TriFThiazole.html
						Last Modified 2 Oct 2004