CH3C(=O)CN
	Nitrogen
	Nuclear Quadrupole Coupling Constants
		in Acetyl Cyanide
	Calculation was made of the nitrogen nqcc's in acetylyl cyanide on an approximate equilibrium structure ~re,  derived here by MP2/aug-cc-pVTZ(G03) optimization with empirically corrected bond lengths.  These calculated nqcc's are compared with the experimental values [1] in Table 1.  Structure parameters are given in Z-matrix format in Table 2.
	In Table 1, 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 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 B3PW91/6-311+G(df,pd) model for calculation of the nqcc's.
	Table 1.  Nitrogen nqcc's in CH3C(=O)CN (MHz).  Calculation was made on the ~re structure.     Calc. Expt. [1]     14N Xaa - 4.649 - 4.34(7) Xbb 1.719 2.03(31) Xcc 2.931 2.31(31) |Xab| 0.532   RMS 0.44 (15 %) RSD 0.030 (1.3 %)   Xxx 1.762 Xyy 2.931 Xzz - 4.694 ETA 0.249 Øz,a 4.75 Øa,CN 5.23 Øz,CN 0.48
	Table 2.  CH3C(=O)CN Molecular structure parameters (Å and degrees).    C  C, 1, R2  O, 2, R3, 1, A3  C, 2, R4, 1, A4, 3, 180., 0  H, 4, R5, 2, A5, 1, 180., 0  H, 4, R6, 2, A6, 1,  D, 0  H, 4, R6, 2, A6, 1, -D, 0  N, 1, R7, 2, A7, 4,  0., 0       Variables:  R2 = 1.4794  R3 = 1.2075  R4 = 1.4944  R5 = 1.08551034  R6 = 1.09055853  R7 = 1.1575  A3 = 119.78646324  A4 = 114.75083739  A5 = 109.73388275  A6 = 109.32934103  A7 = 178.87999263  D   = 58.53861195
	[1] F.Scappini and H.Dreizler, Z.Naturforsch. 31a,840(1976).
	HC(=O)CN		CH3C(=O)Cl		HC(=O)Cl		CH3CDO
	H2C=O		O=CCl2		O=CBr2		CH2(CN)-C(=O)H
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	Molecules/Nitrogen
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						Last Modified 3 Feb 2009