Tropinone:  N-Methyl-8-Azabicyclo[3.2.1]octan-3-one
	Nitrogen
	Nuclear Quadrupole Coupling Constants
		in Tropinone
	Calculation of the N nqcc tensors was made here on molecular structures of equatorial and axial tropinone optimized at the B3P86/6-31G(3d,3p) level of theory, and on an reSE structure of equatorial tropinone derived by Demaison et al. [1].  Calculation of the molecular PE at the B3PW91/6-311+G(df,pd) level of theory on these optimized structures gives Eax < Eeq by about 0.4 kJ/mol, in constrast to the experimental result where Eeq < Eax by ca. 2 kJ/mol [1].  Calculated nqcc's are compared with the experimental values [2] 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.
	RMS is the root mean square difference between calculated and experimental diagonal nqcc's (percent of the average of the magnitudes of experimental nqcc's).  RSD is the residual standard deviation of the B3PW91/6-311+G(df,pd) model for calculation of the coupling constants.
	Table 1. 14N nqcc's in equatorial Tropinone (MHz).  Calculation was made on the B3P86/6-31G(3d,3p) ropt structure, and on the reSE structure.     Calc/ropt Calc/reSE   Expt [2]     14N Xaa 2.012 2.235 2.1433(49) Xbb 2.557 2.495 2.499(11) Xcc - 4.570 - 4.729 - 4.642(11) |Xac| 2.374 1.860   RMS 0.093 (3.0 %) 0.073 (2.4 %) RSD 0.030 (1.3 %) 0.030 (1.3 %)   Xxx 2.779 2.700 Xyy 2.557 2.495 Xzz - 5.337 - 5.195 ETA - 0.0417 - 0.0396 Øz,a 107.90 104.05 Øa,N-Me     0.19     4.94 Øz,N-Me 108.10 108.99
	Table 2. 14N nqcc's in axial Tropinone (MHz).  Calculation was made on the B3P86/6-31G(3d,3p) opt structure.     Calc   Expt [2]     14N Xaa - 2.710 - 2.7703(23) Xbb 0.070 0.1625(45) Xcc 2.640 2.6077(45) |Xab| 3.952   RMS 0.066 (3.6 %)   Xxx 2.869 Xyy 2.640 Xzz - 5.509 ETA - 0.0414 Øz,a   35.31 Øa,N-Me   70.20 Øz,N-Me 105.51
	The B3P86/6-31G(3d,3p) optimized structures of these conformers are given in Z-matrix format here: equatorial and axial.
	Table 3.  Tropinone.  Rotational constants (MHz) and dipole moments (D).  Calc is on the B3P86/6-31G(3d,3p) opt structure.                 ______________equatorial_______________   Calc   Expt [2]   A 2390.8 2391.394(22) B 1161.8 1162.84577(11) C 1119.1 1116.80976(11)   |µa|   3.59 |µb|   0 (sym) |µc|   0.10                 ________________axial_________________   A 1930.0 1915.3226(33) B 1341.8 1337.12661(13) C 1230.3 1225.28465(12)   |µa|   2.96 |µb|   0.58 |µc|   0 (sym)
	[1] J.F.Demaison, N.C.Craig, E.J.Cocinero, J.-U.Grabow, A.Lesarri, and H.D.Rudolf, J.Phys.Chem. A 116,8684(2012).
	[2] E.J.Cocinero, A.Lesarri, P.Écija, J.-U.Grabow, J.A.Fernández, and F.Castaño, Phys.Chem.Chem.Phys. 12,6076(2010).
	Tropane		Trimethylamine		1-Asabicyclo[2.2.2]octane
	Table of Contents
	Molecules/Nitrogen
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						Last Modified 22 Nov 2012