NH2CN
	Nitrogen
	Nuclear Quadrupole Coupling Constants
		in Cyanamide
	Calculation of the nitrogen nqcc tensors in cyanamide was made on the reBO molecular structure of Damaison et al. [1] and on the reSE structure of Kraśnicki et al. [2].  These are compared with the experimental nqcc's [3,4] in Tables 1 - 4.  Structure parameters are given in Table 5.
	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 b-axis, these are perpendicular to the Cs 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 nqcc's (percentage of average experimental nqcc).  RSD is the residual stand deviation of calibration of the model for calculation of the nqcc's.
	Table 1.  14N (amine) nqcc's in NH2CN (MHz).  Calculation was made on the reBO structure [1].     Calc. Expt. [3] Expt. [4]     Xaa 2.888 3.124(11) 3.051(18) Xbb 1.682 1.821(8) 1.851 Xcc - 4.570 - 4.945 - 4.902(16) |Xac| 1.342   RMS 0.268 (8.1 %) 0.235 (7.2 %) RSD 0.030 (1.3 %) 0.030 (1.3 %)   Xxx 3.122 Xyy 1.682 Xzz - 4.804 ETA - 0.300 Øx,a   9.89 Øx,NC   2.75 Øx,NC 12.64
	Table 2.  14N (amine) nqcc's in NH2CN (MHz).  Calculation was made on the reSE structure [2].     Calc. Expt. [3] Expt. [4]     Xaa 2.910 3.124(11) 3.051(18) Xbb 1.721 1.821(8) 1.851 Xcc - 4.631 - 4.945 - 4.902(16) |Xac| 1.390   RMS 0.227 (6.9 %) 0.192 (5.9 %) RSD 0.030 (1.3 %) 0.030 (1.3 %)   Xxx 3.158 Xyy 1.721 Xzz - 4.879 ETA - 0.295 Øx,a 10.12 Øx,NC Øx,NC
	Table 3.  14N (cyano) nqcc's in NH2CN (MHz).  Calculation was made on the reBO structure [1].     Calc. Expt. [3] Expt. [4]     Xaa - 3.345 - 3.341(11) - 3.316(18) Xbb 2.917 2.881(7) 2.862 Xcc 0.429 0.460 0.454(16) |Xac| 0.084   RMS 0.023 (1.1 %) 0.039 (1.7 %) RSD 0.030 (1.3 %) 0.030 (1.3 %)   Xxx 0.430 Xyy 2.917 Xzz - 3.347 ETA 0.743 Øz,a   1.27 Øa,CN   0.19 Øz,CN   1.46
	Table 4.  14N (cyano) nqcc's in NH2CN (MHz).  Calculation was made on the reSE structure [2].     Calc. Expt. [3] Expt. [4]     Xaa - 3.328 - 3.341(11) - 3.316(18) Xbb 2.941 2.881(7) 2.862 Xcc 0.387 0.460 0.454(16) |Xac| 0.039   RMS 0.055 (2.5 %) 0.060 (2.7 %) RSD 0.030 (1.3 %) 0.030 (1.3 %)   Xxx 0.387 Xyy 2.941 Xzz - 3.328 ETA 0.767 Øz,a   0.60 Øa,CN    Øz,CN
	Table 5.  NH2CN Structure parameters, reBO [1] and  reSE [2] (Å and degrees).     reBO   reSE CN(cy) 1.1587 1.1594(2) N(am)C 1.3482 1.3470(2) NH 1.0072 1.0059(1) HNC 113.39 NCN 177.06 178.22(17) HNCN 115.39 HNH 112.74(2)   Ø   42.78(9) Ø is angle between the NC bond axis and the HNH bisector.
	[1] J.Demaison, A.G.Császár, I.Kleiner, and H.Møllendal, J.Chem.Phys.A 111,2574(2007).
	[2] A.Kraśnicki, Z.Kisiel, W.Jabs, B.P.Winnewisser, and M.Winnewisser, J.Mol.Spectrosc. 267,144(2011).
	[3] R.D.Brown, P.D.Godfrey, M.Head-Gordon, K.H.Wiedenmann, and B.Kleibömer, J.Mol.Spectrosc. 130,213(1988).
	[4] W.G.Read, E.A.Cohen, and H.M.Pickett, J.Mol.Spectrosc. 115,316(1986).
	J.K.Tyler, J.Sheridan, and C.C.Costain, J.Mol.Spectrosc. 43,248(1972)
	J.N.Macdonald, D.Taylor, J.K.Tyler, and J.Sheridan, J.Mol.Spectrosc. 26,285(1968).
	D.J.Millen, G.Topping, and D.R.Lide Jr. J.Mol.Spectrosc. 8,153(1962).
	NH2F		NH2OH		BH2NH2		BF2NH2
	B2H5NH2		NCl3		NH3		NH2Cl
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	Molecules/Nitrogen
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						Last Modified 17 March 2011