4-Fluorothiazole
	Nitrogen and Sulfur
	Nuclear Quadrupole Coupling Constants
		in 4-Fluorothiazole
	Calculation of nitrogen and sulfur nqcc's in 4-fluorothiazole 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 4-Fluorothiazole-32S (MHz).  Calculation was made on the B3PW91/6-31G(2d,2pd) ropt structure.     Calc. Expt.     14N Xaa - 0.268 Xbb - 2.018 Xcc 2.286 |Xab| 2.702   RSD 0.030 (1.3 %)   Xxx 1.697 Xyy 2.286 Xzz - 3.984 ETA 0.148 Øz,a 53.97 Øa,bi 55.41 Øz,bi*   1.44
	* The z-axis makes an angle of 1.44o with the external bisector ( 'bi' ) of the C(2)N(3)C(4) and tilts toward C(4).
	Table 2. Nitrogen nqcc's in 4-Fluorothiazole-33S (MHz).  Calculation was made on the B3PW91/6-31G(2d,2pd) ropt structure.     Calc. Expt.     14N Xaa - 0.315 Xbb - 1.971 Xcc 2.286 |Xab| 2.717   RSD 0.030 (1.3 %)
	Table 3. Nitrogen nqcc's in 4-Fluorothiazole-34S (MHz).  Calculation was made on the B3PW91/6-31G(2d,2pd) ropt structure.     Calc. Expt.     14N Xaa - 0.315 Xbb - 1.971 Xcc 2.286 |Xab| 2.717   RSD 0.030 (1.3 %)
	Table 4.  33S nqcc's in  4-Fluorothiazole (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   1.76   1.82 Xbb - 22.06 - 22.17 Xcc 20.30 20.35 |Xab| 12.65 12.74   RSD 0.39 (1.7 %) 0.35 (1.5 %)   Xxx   7.22   7.33 Xyy 20.20 20.35 Xzz - 27.52 - 27.67 ETA 0.475 0.470 Øx,a 23.35 23.36 Øa,bi 20.52 20.52 Øx,bi*   2.83   2.84
	* The x-axis makes an angle of 2.83o / 2.84o with the external bisector ( 'bi' ) of the C(5)S(1)C(2) and tilts toward C(5).
	Table 5.   4-Fluorothiazole and Thiazole.  Structure parameters, ropt (Å and degrees).   X = F X = H S(1)C(2) 1.7272 1.7313 C(2)N(3) 1.3011 1.2988 N(3)C(4) 1.3532 1.3690 C(4)C(5) 1.3633 1.3635 C(5)S(1) 1.7197 1.7187 C(2)H(2) 1.0812 1.0818 C(4)X(4) 1.3203 1.0818 C(5)H(5) 1.0766 1.0781 C(5)S(1)C(2)   89.37   89.03 S(1)C(2)N(3) 115.30 115.14 C(2)N(3)C(4) 109.28 110.28 N(3)C(4)C(5) 117.98 116.09 C(4)C(5)S(1) 108.06 109.46 S(1)C(2)H(2) 120.72 120.56 N(3)C(4)X(4) 118.01 119.18 C(4)C(5)H(5) 129.02 129.10
	Table 6.  4-Fluorothiazole-32S.  Atomic coordinates, ropt   a (Å)   b (Å) S(1) - 1.5472 - 0.3866 C(2) - 0.8301 1.1846 N(3) 0.4709 1.2020 C(4) 0.9348 - 0.0692 C(5) 0.0232 - 1.0828 H(2) - 1.4463 2.0730 F(4) 2.2424 - 0.2520 H(5) 0.1919 - 2.1461
	Table 7.  2-Fluorothiazole-32S.  Rotational Constants (MHz).   Calc. ropt A  7639.1 B  2577.4 C  1927.2
	Thiazole			2-Fluorothiazole			5-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
						4FThiazole.html
						Last Modified 2 Oct 2004