NCC(=O)NH2
	Nitrogen
	Nuclear Quadrupole Coupling Constants
	in Cyanoformamide
	Nitrogen nqcc's in cyanoformamide were determined by Christiansen [1].  An ab initio re molecular structure was determined by Winnewisser et al. [2].
	Calculation of the nitrogen nqcc's was made on this re structure.  These are compared with the experimental nqcc's in Tables 1 and 2.  Structure parameters are given in Table 3.
	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.  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.
	RMS is the root mean square difference between calculated and experimental diagonal nqcc's (percentage of average experimental nqcc).  RSD is the residual stand deviation of calibration of the B3PW91/6-311+G(df,pd) model for calculation of the nqcc's.
	Table 1.  Amide Nitrogen nqcc's in Cyanoformamide (MHz).  Calculation was made on the re molecular structure.     Calc. Expt. [1]     14N Xaa 1.785 1.63(10) Xbb - Xcc 6.045 5.95(10) Xbb 2.130 2.16 Xcc - 3.915 - 3.79 |Xab| 0.151   RMS 0.12 (4.6 %) RSD 0.030 (1.3 %)   Xxx 1.728 Xyy 2.187 Xzz * - 3.915 ETA 0.117
	* The principal z-axis is perpendicular to the plane of the molecule.
	Table 2.  Cyano Nitrogen nqcc's in Cyanoformamide (MHz).  Calculation was made on the re molecular structure.     Calc. Expt. [1]     14N Xaa - 4.620 - 4.56(15) Xbb - Xcc - 0.632 - 0.20(30) Xbb 1.994 2.18 Xcc 2.626 2.38 |Xab| 0.223   RMS 0.18 (6.0 %) RSD 0.030 (1.3 %)   Xxx 2.002 Xyy 2.626 Xzz - 4.627 ETA 0.135 Øz,a 1.93 Øa,CN 1.97 Øz,CN 0.04
	Table 3.  Cyanoformamide.  Molecular structure parameters, re [2] (Å and degrees).   Point Group CS O=C 1.207 CC 1.482 CN(4) 1.157 CN(5) 1.351 CH(6) 1.002 CH(7) 1.004 OCC 121.3 CCN 179.4 OCN 126.0 CNH(6) 121.4 CNH(7) 118.4
	[1] J.J.Christiansen, J.Mol.Spectrosc., 231,131(2005).
	[2] M.Winnewisser, I.Medvedev, F.C.DeLucia, E.Herbst, J.Koput, K.V.L.N.Sastry, and R.A.H.Butler, The Astro. Phys. J. Supp. Series, 159,189(2005).
	cyanamide		acetylcyanide		formamide
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	Molecules/Nitrogen
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						Last Modified 27 Aug 2009