H-N=CH-CN
		Nitrogen
	Nuclear Quadrupole Coupling Constants
	in Cyanomethanimine
	Calculation of the nitrogen nqcc's in the E and Z isomers of cyanomethanimine was made here on molecular structures given by MP2/6-311+G(3d,3p) optimizations (see methylenimine).  These are compared with the experimental nqcc's [1] in Tables 1 and 4.  Structure parameters are given in Table 5, rotational constants in Table 6.
		E-C-Cyanomethanimine				Z-C-Cyanomethanimine
	In Tables 1 and 4, subscripts a,b,c refer to the principal axes of the inertia tensor; x,y,z to the principal axes of the nqcc tensor.  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 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 nitrogen nqcc's.
	Table 1.  Imine Nitrogen nqcc's in E-C-Cyanomethanimine (MHz).  Calculation was made on the MP2/6-311+G(3d,3p) optimized structure (see below).     Calc. Expt. [1]     14N (Im) Xaa 0.723 0.764(11) Xbb - 4.562 - 4.459(24) Xcc 3.839 3.695(24) |Xab| 0.625   RMS 0.105 (3.5 %) RSD 0.030 (1.3 %)   Xxx 0.796 Xyy 3.839 Xzz - 4.635 ETA 0.656 Øz,a 96.65 Øa,bi 98.82 Øz,bi*   2.17
	* The z-principal axis makes an angle of 2.17o with the external bisector of the HNC angle, and tilts away from CN.
	Table 2.  Cyano Nitrogen nqcc's in E-C-Cyanomethanimine (MHz).  Calculation was made on the MP2/6-311+G(3d,3p) optimized structure (see below).     Calc. Expt. [1]     14N (Cy) Xaa - 4.185 - 4.160(10) Xbb 1.610 1.658(31) Xcc 2.575 2.502(31) |Xab| 1.518   RMS 0.052 (1.9 %) RSD 0.030 (1.3 %)   Xxx 1.984 Xyy 2.575 Xzz - 4.558 ETA 0.130 Øz,a 13.82 Øa,CN 12.74 Øz,CN   1.08
	Table 3.  Imine Nitrogen nqcc's in Z-C-Cyanomethanimine (MHz).  Calculation was made on the MP2/6-311+G(3d,3p) optimized structure (see below).     Calc. Expt. [1]     14N (Im) Xaa - 4.252 - 4.171(21) Xbb 0.441 0.401(32) Xcc 3.811 3.770(32) |Xab| 1.280   RMS 0.057 (2.0 %) RSD 0.030 (1.3 %)   Xxx 0.767 Xyy 3.811 Xzz - 4.578 ETA 0.665 Øz,a 14.30 Øa,bi 14.97 Øz,bi*   0.66
	* The z-principal axis makes an angle of 0.66o with the external bisector of the HNC angle, and tilts away from the CH bond.
	Table 4.  Cyano Nitrogen nqcc's in Z-C-Cyanomethanimine (MHz).  Calculation was made on the MP2/6-311+G(3d,3p) optimized structure (see below).     Calc. Expt. [1]     14N (Cy) Xaa - 4.053 - 4.078(21) Xbb 1.523 1.581(42) Xcc 2.530 2.497(42) |Xab| 1.754   RMS 0.041 (1.5 %) RSD 0.030 (1.3 %)   Xxx 2.028 Xyy 2.530 Xzz - 4.559 ETA 0.110 Øz,a 16.09 Øa,CN 15.69 Øz,CN   0.39
	Table 5.  Cyanomethanimine.  Molecular structure parameters, ropt = MP2/6-311+G(3d,3p) optimization, with MP2/6-311+G(d,p) correction for CN bond length [2]. (Å and degrees).   E-C-Cyanomethanimine E-C Z-C N(2)H(4) 1.0203 1.0215 N(2)C(1) 1.2800 1.2804 C(1)H(3) 1.0882 1.0844 C(1)C(5) 1.4477 1.4494 Z-C-Cyanomethanimine C(5)N(6) 1.157 1.158 H(4)N(2)C(1) 109.20 110.46 N(2)C(1)H(3) 125.09 119.14 N(2)C(1)C(5) 119.69 124.68 C(1)C(5)N(6) 176.65 179.37
	Table 6.  Cyanomethanimine.  Rotational Constants, ropt structures (MHz).      E-C    Z-C A 62 420.4 54 203.0 B   4 964.0   5 060.8 C   4 598.3   4 628.7
	[1] H.Krause and D.H.Sutter, Z.Naturforsch. 47a,573(1992).
	[2] J.Demaison, J.Cosléou, R.Bocquet, and A.G.Lesarri, J.Mol.Spectrosc. 167,400(1994).
	CH2NH		CF2NH		(CH3)2NH		Ethylenimine
	cis-Ethanimine			trans-Ethanimine
	trans-syn-Propenimine			trans-anti-Propenimine
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	Molecules/Nitrogen
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						Last Modified 15 July 2006