C3H5N
	Nitrogen
	Nuclear Quadrupole Coupling Constants
		in 3-Methyl-2H-Azirine
	The microwave spectrum of 3-methyl-2H-azirine was observed by Sugie et al. [1].  Hyperfine structure due to 14N quadrupole interaction was, however, not resolved.
	Calculation of the nitrogen nqcc tensor was made here on an ropt molecular structure derived by B3LYP/6-31G(3d,3p) optimization.  These nqcc's are given in Table 1.  Structure parameters are given in Table 2, rotational constants and electric dipole moments in Table 3, quartic centrifugal distortion constants in Table 4.
	In Table 1, subscripts a,b,c refer to the principal axes of the inertia tensor, x,y,z to principal axes of the nqcc tensor.  The nqcc y-axis is chosen coincident with the inertia c-axis, these are perpendicular to the symmetry 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 B3PW91/6-311+G(df,pd) model for calculation of the efg's/nqcc's.
	Table 1.  Nitrogen nqcc's in 3-Me-2H-Azirine (MHz).  Calculation was made on the B3LYP/6-31G(3d,3p) optimized molecular structure.     Calc. Expt.     14N Xaa - 1.467 Xbb - 0.411 Xcc 1.878 |Xab| 2.236   RSD 0.030 (1.3 %)   Xxx 1.359 Xyy 1.878 Xzz - 3.237 ETA 0.160 Øz,a 38.36 Øa,N=C 43.32 Øz,N=C   4.96
	Table 2.  3-Me-2H-Azirine.  Molecular structure parameters, ropt = B3LYP/6-31G(3d,3p) (Å and degrees).  N  C,1,B1  C,2,B2,1,A1  H,3,B3,2,A2,1,D1,0  H,3,B4,2,A3,1,D2,0  C,2,B5,1,A4,3,D3,0  H,6,B6,2,A5,1,D4,0  H,6,B7,2,A6,1,D5,0  H,6,B8,2,A7,1,D6,0  B1=1.25399444  B2=1.45051644  B3=1.08795639  B4=1.08795639  B5=1.47779269  B6=1.09405845  B7=1.09405845  B8=1.09197254  A1=69.20595308  A2=120.89961506  A3=120.89961506  A4=140.85734751  A5=110.06942167  A6=110.06942167  A7=110.65072086  D1=99.85872536  D2=-99.85872536  D3=180.  D4=121.06592461  D5=-121.06592461  D6=0.
	Table 3.  3-Me-2H-Azirine.  Rotational Constants (MHz) and Dipole Moments (D), ropt = B3LYP/6-31G(3d,3p)   ropt     Expt [1] A 22610.8 22338.04(4) B   6604.9   6618.622(9) C   5473.4   5464.442(7) |µa| * 2.01 1.90(5) |µb| * 1.97 1.86(5) * B3PW91/6-311+G(df,pd) on ropt structure.
	Table 4.  3-Me-2H-Azirine.  Quartic Centrifugal Distortion Constants (kHz).  Calc = MP2/cc-pVTZ and B3LYP/cc-pVTZ. MP2 B3LYP Expt [1] Delta_J 1.81   1.88 1.91(6) Delta_JK 8.42   7.53 7.6(5) Delta_K 73.7   76.4 150.6(5) delta_j 0.415   0.431 0.443(6) delta_k 6.07   3.36 3.1(4)
	[1] M.Sugie, H.Takeo, and C.Matsumura, J.Mol.Struct. 413-414,387(1997).
	Ethylenimine		2H-Azirine		3-F-2H-Azirine
	Table of Contents
	Molecules/Nitrogen
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						Last Modified 30 Oct 2013