NC5H4-C(=O)NH2
	Nitrogen
	Nuclear Quadrupole Coupling Constants
		in Nicotinamide
		(Pyridine-3-carboxamide)
	The microwave spectrum of nicotinamide was observed by Vogelsanger, et al. [1].  E- and Z-conformers, shown below, have been identified.
	E-Nicotinamide				Z-Nicotinamide
		At the B3P86/6-31G(3d,3p) opt level of theory, EE < EZ by 3.8 kJ/mol.
	Calculation of the nitrogen nqcc tensors in nicotinamide was made here on molecular structures given by B3P86/6-31G(d,p) and B3P86/6-31G(3d,3pd) optimization.  These calculated nqcc's are given in Tables 1 and 4, rotational constants in Table 5.  Structure parameters are given here in Z-matrix format.
	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.  ETA = (Xxx - Xyy)/Xzz.  Ø (degrees) is the angle between its subscripted parameters.
	RSD is the residual standard deviation of calibration of the B3PW91/6-311+G(df,pd) model for calculation of the efg's/nqcc's.
	Table 1.  Pyrridinic Nitrogen nqcc's in E-Nicotinamide (MHz).  Calculation was made here on molecular structures given by (1) B3P86/6-31G(d,p) and (2) B3P86/6-31G(3d,3pd) optimization.   Calc (1) Calc (2) Expt   Xaa - 0.025 - 0.021 Xbb - 3.284 - 3.310 Xcc 3.309 3.331 Xab - 2.701 - 2.688 Xac - 0.290 - 0.294 Xbc - 0.762 - 0.762 RSD 0.030 (1.3 %) 0.030 (1.3 %) Xxx 1.492 1.479 Xyy 3.396 3.417 Xzz - 4.888 - 4.896 ETA 0.390 0.396 Øz,bi *
	* "bi" is the bisector of the CNC angle.
	Table 2.  Amide Nitrogen nqcc's in E-Nicotinamide (MHz).  Calculation was made here on molecular structures given by (1) B3P86/6-31G(d,p) and (2) B3P86/6-31G(3d,3pd) optimization.   Calc (1) Calc (2) Expt   Xaa 1.916 1.911 Xbb 1.236 1.152 Xcc - 3.152 - 3.063 Xab - 0.163 - 0.153 Xac - 0.189 - 0.146 Xbc - 2.081 - 2.133 RSD 0.030 (1.3 %) 0.030 (1.3 %) Xxx 1.888 1.874 Xyy 2.104 2.086 Xzz - 3.992 - 3.960 ETA 0.0539 0.0533 Øz,CN
	Table 3.  Pyrridinic Nitrogen nqcc's in Z-Nicotinamide (MHz).  Calculation was made here on molecular structures given by (1) B3P86/6-31G(d,p) and (2) B3P86/6-31G(3d,3pd) optimization.   Calc (1) Calc (2) Expt   Xaa - 0.110 - 0.137 Xbb - 3.283 - 3.265 Xcc 3.393 3.402 Xab - 2.729 - 2.739 Xac 0.394 0.401 Xbc 0.851 0.880 RSD 0.030 (1.3 %) 0.030 (1.3 %) Xxx 1.457 1.448 Xyy 3.501 3.518 Xzz - 4.958 - 4.966 ETA 0.412 0.417 Øz,bi *
	* "bi" is the bisector of the CNC angle.
	Table 4.  Amide Nitrogen nqcc's in Z-Nicotinamide (MHz).  Calculation was made here on molecular structures given by (1) B3P86/6-31G(d,p) and (2) B3P86/6-31G(3d,3pd) optimization.   Calc (1) Calc (2) Expt   Xaa 1.915 1.909 Xbb 0.912 0.809 Xcc - 2.827 - 2.717 Xab 0.137 0.121 Xac - 0.107 - 0.064 Xbc 2.381 2.429 RSD 0.030 (1.3 %) 0.030 (1.3 %) Xxx 1.887 1.875 Xyy 2.102 2.083 Xzz 3.989 3.958 ETA 0.0538 0.0525 Øz,CN
	Table 5.  Nicotinamide.  Rotational Constants (MHz).  Calc (1) = B3P86/6-31G(d,p) opt, Calc (2) = B3P86/6-31G(3d,3p) opt. Calc (1) Calc (2)    Expt E-Nicotinamide A  3900  3912 B  1239  1242 C    950    953 Z-Nicotinamide A  3899  3912 B  1236  1238 C    953    956
	[1] B.Vogelsanger, R.D.Brown, P.D.Godfrey, and A.Pierlot, J.Mol.Spectrosc. 145,1(1991).
	Formamide		Acetamide		2-Fluorobenzylamine		Cyanoformamide
	Pyridine		3-Methylpyridine		3-Hydroxypyridine		Pyridine-3-Carbaldehyde
	Nicotinic Acid
	Table of Contents
	Molecules/Nitrogen
						Nicotinamide.html
						Last Modified 6 Feb 2014