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3-CH3-C5H4N
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Nitrogen
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Nuclear
Quadrupole Coupling Constants |
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in 3-Methylpyridine |
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Calculation was made of the
nitrogen nqcc's in 3-methylpyridine on a structure given by
B3P86/6-31G(3d,3p) optimization. These are given inTable 1.
Structure parameters are given in Table 2, atomic coordinates in
Table 3, and rotational constants in Table 4.
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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
molecular plane. Ø (degrees) is the angle between its
subscripted parameters. ETA = (Xxx - Xyy)/Xzz.
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RSD
is the calibration residual standard deviation of the B3PW91/6-311+G(df,pd) model for
calculation of the nqcc's. |
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Table 1. Nitrogen nqcc's in 3-Methylpyridine (MHz). Calculation
was made on the B3P86/6-31G(3d,3p) ropt structure. |
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Calc. |
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Expt. |
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14N |
Xaa |
- |
0.116 |
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Xbb |
- |
3.396 |
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Xcc |
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3.512 |
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|Xab| |
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2.716 |
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RSD |
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0.030 (1.3 %) |
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Xxx |
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1.417 |
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Xyy |
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3.512 |
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Xzz |
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4.929 |
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ETA |
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0.425 |
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Øz,a |
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60.56 |
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Øa,bi |
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60.46 |
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Øz,bi * |
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0.10 |
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* The z-axis makes an angle of 0.10o
with the external bisector ( 'bi' ) of the C(6)N(1)C(2) angle, and tilts
toward C(2). |
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| Table 2. 3-Methylpyridine and Pyridine. Molecular structure parameters, ropt (Å
and degrees). |
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3-Me-Pyridine |
Pyridine |
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N(1)C(2) |
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1.3297 |
1.3336 |
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C(2)C(3) |
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1.3979 |
1.3904 |
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C(3)C(4) |
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1.3910 |
1.3885 |
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C(4)C(5) |
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1.3894 |
1.3885 |
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C(5)C(6) |
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1.3876 |
1.3904 |
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C(6)N(1) |
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1.3346 |
1.3336 |
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C(2)H(2) |
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1.0899 |
1.0880 |
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C(4)H(4) |
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1.0863 |
1.0851 |
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C(5)H(5) |
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1.0845 |
1.0845 |
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C(6)H(6) |
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1.0876 |
1.0880 |
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C(6)N(1)C(2) |
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117.24 |
117.03 |
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N(1)C(2)C(3) |
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124.74 |
123.80 |
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C(2)C(3)C(4) |
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116.72 |
118.44 |
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C(3)C(4)C(5) |
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119.51 |
118.50 |
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C(4)C(5)C(6) |
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118.52 |
118.44 |
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C(5)C(6)N(1) |
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123.26 |
123.80 |
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N(1)C(2)H(2) |
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115.82 |
115.94 |
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C(3)C(4)H(4) |
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120.03 |
120.75 |
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C(4)C(5)H(5) |
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121.13 |
121.35 |
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C(5)C(6)H(6) |
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120.62 |
120.26 |
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C(3)C(7) |
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1.5010 |
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C(7)H(8) |
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1.0918 |
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C(7)H(9,10) |
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1.0939 |
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C(2)C(3)C(7) |
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120.94 |
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C(3)C(7)H(8) |
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111.21 |
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C(3)C(7)H(9,10) |
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111.30 |
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| Table 3. 3-Methylpyridine. Atomic coordinates, ropt. |
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a (Å) |
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b (Å) |
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c (Å) |
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N(1) |
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1.1428 |
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1.1952 |
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C(2) |
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0.1863 |
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1.1525 |
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C(3) |
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0.9454 |
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0.0213 |
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C(4) |
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0.2419 |
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1.2213 |
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C(5) |
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1.1474 |
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1.2002 |
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C(6) |
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1.7914 |
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0.0289 |
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H(2) |
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0.6923 |
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2.1178 |
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H(4) |
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0.7783 |
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2.1659 |
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H(5) |
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1..7221 |
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2.1199 |
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H(6) |
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2.8776 |
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0.0852 |
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C(7) |
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2.4455 |
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0.0298 |
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H(8) |
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2.8749 |
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0.9740 |
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H(9,10) |
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2.8253 |
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0.5569 |
± |
0.8801 |
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| Table 4. 3-Methylpyridine. Rotational Constants
(MHz). |
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Calc ropt |
Expt. |
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A |
5737.6 |
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B |
2596.8 |
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C |
1807.6 |
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Pyridine |
2-Methylpyridine |
4-Methylpyridine |
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3-Fluoropyridine |
3-Chloropyridine |
3-Bromopyridine |
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3-Cyanopyridine |
3-Pyridine Carbaldehyde |
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Table of Contents
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Molecules/Nitrogen |
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3MePYR.html |
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Last
Modified 21 Nov 2003 |
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