Tropane:  N-Methyl-8-Azabicyclo[3.2.1]octane
	Nitrogen
	Nuclear Quadrupole Coupling Constants
		in Tropane
	Calculation of the N nqcc tensors was made here on molecular structures of equatorial and axial tropane  optimized at the  B3P86/6-31G(3d,3p) level of theory.  These structures are shown below.  Calculation of the molecular PE at the B3PW91/6-311+G(df,pd) level of theory on these optimized structures gives Eeq < Eax by about 2.8 kJ/mol.  Calculated nqcc's are given in Tables 1 and 2.  Rotational constants and dipole moments are given in Table 3.
		eq				ax
	In Tables 1 and 2, 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.  ETA = (Xxx - Xyy)/Xzz.   Ø (degrees) is the angle between its subscripted parameters.  Øz,N-Me is the angle between the N-CH3 bond direction and the external z-axis.
	Table 1. 14N nqcc's in equatorial Tropane (MHz).  Calculation was made on the B3P86/6-31G(3d,3p) opt structure.     Calc   Expt     14N Xaa 2.049 Xbb 2.482 Xcc - 4.531 |Xac| 2.383   Xxx 2.821 Xyy 2.482 Xzz - 5.304 ETA - 0.0639 Øz,a 107.96 Øa,N-Me     0.08 Øz,N-Me 108.04
	Table 2. 14N nqcc's in axial Tropane (MHz).  Calculation was made on the B3P86/6-31G(3d,3p) opt structure.     Calc   Expt     14N Xaa 2.660 Xbb - 5.300 Xcc 2.639 |Xab| 1.474   Xxx 2.924 Xyy 2.639 Xzz - 5.564 ETA - 0.0512 Øz,a   79.84 Øa,N-Me   25.85 Øz,N-Me 105.69
	The B3P86/6-31G(3d,3p) optimized structures of these conformers are given in Z-matrix format here: equatorial and axial.
	Table 3.  Tropane.  Rotational constants (MHz) and dipole moments (D).  Calc is on the B3P86/6-31G(3d,3p) opt structure.                 ______________equatorial_______________   Calc   Expt.   A 2401.2 B 1648.3 C 1568.9   |µa|   0.18 |µb|   0 (sym) |µc|   0.80                 ________________axial_________________   A 2001.3 B 1853.6 C 1700.7   |µa|   0.23 |µb|   0.69 |µc|   0 (sym)
	Tropinone		Trimethylamine		1-Asabicyclo[2.2.2]octane
	Table of Contents
	Molecules/Nitrogen
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						Last Modified 8 Aug 2010