CH3CH2CH2CN
	Nitrogen
	Nuclear Quadrupole Coupling Constants
		in t-1-Cyanopropane
	Calculation of the nitrogen nqcc's in the trans conformer of 1-cyanopropane was made here on a molecular structure derived ab initio with correction as discussed below. These are compared in Table 1 with the experimental nqcc's of Demaison and Dreizler [1].  Structure parameters are given in Table 2, rotational constants in Table 3.
	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 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 standard deviation of calibration of the B3PW91/6-311+G(df,pd) model for calculation of the nqcc's.
	Table 1. Nitrogen nqcc's in t-1-Cyanopropane (MHz).     Calc. Expt. [1]     14N Xaa - 3.428 - 3.405(45) Xbb 1.364 1.341(50) Xcc 2.064 2.064(39) |Xab| 2.088   RMS 0.019 (0.83 %) RSD 0.030 (1.3 %)   Xxx 2.146 Xyy 2.064 Xzz - 4.210 ETA - 0.019 Øz,a 20.53 Øa,CN 20.92 Øz,CN   0.38
	Molecular Structure
	The molecular structure was optimized at the MP2/6-311+G(d,p) level of theory assuming Cs symmetry.  The optimized CC and CN bond lengths were then corrected using equations obtained from linear regression analysis of the data given in Ref. [2].  The CH bond lengths were corrected using r = 1.001 ropt, where ropt is obtained by MP2/6-31G(d,p) optimization [3]. Interatomic angles are those given by MP2/6-311+G(d,p) optimization.
	Table 2.  t-1-Cyanopropane.  Heavy atom molecular structure parameters (Å and degrees).  Complete structure is given here in Z-matrix format.     C(11)N 1.1562 C(1)C(11) 1.4609 C(1)C(11)N 178.42   C(1)C(2) 1.5280 C(2)C(3) 1.5195 C(11)C(1)C(2) 112.21 C(1)C(2)C(3) 111.33
	Table 3.  t-1-Cyanopropane.  Rotational Constants (MHz). Calc. ropt    Expt. A 23 908.0 B   2 284.1 C   2 168.8
	[1] J.Demaison and H.Dreizler, Z.Naturforsch. 37a,199(1982).
	[2] J.Demaison, J.Cosléou, R.Bocquet, and A.G.Lesarri, J.Mol.Spectrosc. 167,400(1994).
	[3] J.Demaison and G.Wlodarczak, Structural Chem. 5,57(1994).
	n-Butyl Cyanide, anti-anti				1-Cyanopropane, gauche
	n-Butyl Cyanide, anti-gauche				CH3CN
	n-Butyl Cyanide, gauche-anti				CH3CH2CN
	Table of Contents
	Molecules/Nitrogen
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						Last Modified 29 June 2006