N-acetyl-glycinamide

CH₃C(=O)N(H)-CH₂-C(=O)NH₂

Nitrogen

Nuclear Quadrupole Coupling Constants

in N-Acetyl-Glycinamide

Nitrogen nqcc's in C₇ and C₅ conformers of N-acetyl-glycinamide, as well as best estimate ab initio equilibrium structures, were determined by Puzzarini et al. [1]. Calculation of the nqcc tensors was made here on these r_e structures. Calculated and experimental nqcc's are compared - along with high-level state-of-the-art ab initio calculations made in Ref. [1] - in Tables 1 - 2. Structure parameters are given in Z-matrix format in Table 5.

C₇

C₅ (C_s)

In Tables 1 and 2, subscripts a,b,c refer to the principal axes of the inertia tensor. RMS is the root measn square difference between calculated and experimental nqcc's. 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. ¹⁴N nqcc's in C₇ N-Acetyl-Glycinamide (MHz). Calculation was made on best estimate r_e molecular structure. Atomic numbering is shown below in Table 3.

		Calc		Calc [1]		Expt. [1]

X_aaN(7)		1.235		1.258		1.2553(38)
X_bb		0.970		0.752		0.717(74)
X_cc	-	2.206	-	2.008	-	1.972(74)
X_ab	-	0.744
X_ac		2.143
X_bc		1.824

RMS		0.199 (15. %)
RSD		0.030 (1.3 %)

X_aaN(3)		0.467		0.432		0.3887(69)
X_bb		1.573		1.603		1.593(10)
X_cc	-	2.039	-	2.035	-	1.981(10)
X_ab	-	0.592
X_ac	-	1.937
X_bc	-	1.507

RMS		0.057 (4.4 %)
RSD		0.030 (1.3 %)


Table 2. ¹⁴N nqcc's in C₅ N-Acetyl-Glycinamide (MHz). Calculation was made on best estimate r_emolecular structure. Atomic numbering is shown below in Table 3.

		Calc		Calc [1]		Expt. [1]

X_aaN(7)		2.165		2.159		2.079(65)
X_bb		1.887		1.748		1.787(98)
X_cc	-	4.053	-	3.907	-	3.865(98)
X_ab	-	0.532

RMS		0.133 (5.2 %)
RSD		0.030 (1.3 %)

X_aaN(3)		2.046		1.997		2.113(66)
X_bb		2.064		1.923		2.08(12)
X_cc	-	4.110	-	3.920	-	4.19(12)
X_ab	-	0.077

RMS		0.060 (2.2 %)
RSD		0.030 (1.3 %)


Table 3. N-Acetyl-Glycinamide, best estimate ab initio equilibrium structures (Å and degrees). Z-matrices derived from atomic coordinates given in Ref. [1].


	C C,1,B1 N,2,B2,1,A1 H,3,B3,2,A2,1,D1,0 H,3,B4,2,A3,1,D2,0 O,2,B5,1,A4,3,D3,0 N,1,B6,2,A5,6,D4,0 C,7,B7,1,A6,2,D5,0 O,8,B8,7,A7,1,D6,0 H,7,B9,1,A8,2,D7,0 C,8,B10,7,A9,1,D8,0 H,11,B11,8,A10,7,D9,0 H,11,B12,8,A11,7,D10,0 H,11,B13,8,A12,7,D11,0 H,1,B14,7,A13,8,D12,0 H,1,B15,7,A14,8,D13,0

C₇		C₅

B1 1.52634501 B2 1.34920930 B3 1.00902468 B4 1.00343758 B5 1.21789559 B6 1.44985821 B7 1.35231920 B8 1.22569280 B9 1.00292187 B10 1.50439882 B11 1.08711918 B12 1.08754178 B13 1.08811549 B14 1.09018658 B15 1.08510389 A1 114.38250015 A2 120.27049970 A3 118.43258025 A4 121.57778004 A5 113.06464407 A6 122.18943978 A7 121.48595007 A8 118.69578025 A9 116.45355996 A10 108.46917011 A11 112.98446991 A12 108.38476013 A13 108.79567669 A14 108.24431279 D1 0.00000000 D2 -180.00000000 D3 180.00000000 D4 -115.75674788 D5 -82.09970002 D6 0.00000000 D7 97.90029982 D8 180.00000000 D9 127.12350997 D10 5.35417812 D11 -115.85307001 D12 38.88664906 D13 157.99000990		B1 1.51537182 B2 1.35253750 B3 1.00203698 B4 1.00346758 B5 1.21779270 B6 1.43513851 B7 1.35246260 B8 1.22330759 B9 1.00729148 B10 1.50656062 B11 1.08773389 B12 1.08772678 B13 1.08772678 B14 1.09277878 B15 1.09277878 A1 114.93612013 A2 121.69909985 A3 118.74155025 A4 122.12410004 A5 108.77260001 A6 120.55772002 A7 121.36430995 A8 116.77620008 A9 116.19088012 A10 112.80531999 A11 108.46716997 A12 108.46716997 A13 110.31646013 A14 110.31646013 D1 0.00000000 D2 180.00000000 D3 180.00000000 D4 0.00000000 D5 180.00000000 D6 0.00000000 D7 0.00000000 D8 180.00000000 D9 0.00000000 D10 121.48008992 D11 -121.48008992 D12 -58.87669233 D13 58.87669233

[1] C.Puzzarini, M.Biczysko, V.Barone, L.Largo, I.Peña, C.Cabezas, and J.L.Alonso, J.Phys.Chem. Lett. 5,534(2014).

N-Acetylglycine

Table of Contents

Molecules/Nitrogen

NAGAmide.html

Last Modified 31 March 2016