c-NCHC-CHCN
	Nitrogen
	Nuclear Quadrupole Coupling Constants
		in Maleonitrile
	Calculation of the nitrogen nqcc's in maleonitrile was made on the re molecular structure of Halter et al. [1].  These are compared with the experimental nqcc's [1] in Table 1.  Structure parameters are compared in Table 2.
	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 plane.  Ø (degrees) is the angle between its subscripted parameters.  ETA = (Xxx - Xyy)/Xzz.
	Table 1. Nitrogen nqcc's in Maleonitrile (MHz).  Calculation was made on the re structure of Halter et al. [1].     Calc. Expt. [1]     14N Xaa 0.024 0.0579(15) Xbb - 2.425 - 2.3730 * Xcc 2.401 2.3150 * |Xab| 3.070   RMS 0.064 (4.1 %) RSD 0.030 (1.3 %)   Xxx 2.105 Xyy 2.401 Xzz - 4.506 ETA 0.065 Øz,a 55.87 Øa,CN 55.20 Øz,CN   0.67
	* Calculated here from Xaa and Xbb - Xcc = - 4.688(2) MHz [1].
	Table 2.  Maleonitrile.  Molecular structure parameters, re [1] (Å and degrees).   C=C 1.341 C-C 1.429 CN 1.157 CH 1.075 C=C-C 123.2 C-CN * 178.4 C=CH 119.4    * N's tilt outward.
	[1] R.J.Halter, R.L.Fimmen, R.J.McMahon, S.A.Peebles, R.L.Kuczkowski, and J.F.Stanton, J.Am.Chem.Soc 123,12353(2001).
	(Z)-pent-2-en-4-ynenitrile
	CH2CHCN			Methacrylonitrile
	c-Crotononitrile			t-Crotononitrile
	Table of Contents
	Molecules/Nitrogen
						maleonitrile.html
						Last Modified 23 Oct 2007