t-CH3HC=CHCN			PDF
	Nitrogen
	Nuclear Quadrupole Coupling Constants
		in t-Crotononitrile
	In Table 1, RMS is the root mean square difference between calculated and experimental diagonal nqcc's (percentage of the average of the magnitudes of the experimental nqcc's).  RSD is the calibration residual standard deviation of the B3PW91/6-311+G(df,pd) model for calculation of the nitrogen nqcc's.
	Subscripts a,b,c refer to the principal axes of the inertia tensor; 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 molecular symmetry plane.  Ø (degrees) is the angle between its subscripted parameters.  ETA = (Xxx - Xyy)/Xzz.
	Table 1. Nitrogen nqcc's in t-Crotononitrile (MHz).  Calculation was made on the near-re structure of Lessari et al. [1].     Calc. Expt. [1]     14N Xaa - 3.684 - 3.7192(70) Xbb 1.774 1.7729(92) Xcc 1.910 1.9463(92) |Xab| 1.777   RMS 0.030 (1.2 %) RSD 0.030 (1.3 %)   Xxx 2.302 2.298 * Xyy 1.910 1.9463 Xzz - 4.211 - 4.244 ETA - 0.093 - 0.083 Øz,a 16.54 16.45 Øa,CN 16.61 16.61 Øz,CN   0.1   0.2
	* Calculated here from the diagonal experimental nqcc's and the calculated off-diagonal nqcc.
	Table 2.  Molecular structure parameters, near-re [1] (Å and degrees). Hu is on the same C as CN.  Hc is on the same C as CH3. Hs is the in-plane methyl H, Ha are the out-of-plane methyl H's.   C=C 1.339 C-CN 1.430 Z-Matrix CN 1.158 C-CH3 1.491 CHu 1.083 CHc 1.085 CHs 1.089 CHa 1.091 C=C-CN 122.1 C=C-CH3 123.8 C=CHu 121.1 C=CHc 118.6 C-CHs 111.3 C-CHa 110.5 HaC-C=C 120.8 C-CN 179.4
	[1] A.G.Lesarri, J.Cosléou, X.Li, G.Wlodarczak, and J.Demaison, J.Mol.Spectrosc. 172,520(1995).
	S.L.Hsu and W.H.Flygare, J.Mol.Spectrosc. 37,92(1971).  Xaa = -3.7(±0.1) and Xbb = 1.7(±0.05) MHz.
	Methacrylonitrile			c-Crotononitrile			H2C=CHCN
	Table of Contents
	Molecules/Nitrogen
						t_CroCN.html
						Last Modified 17 June 2004