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2,6-(CN)2-C5H3N
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Nitrogen
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Nuclear
Quadrupole Coupling Constants |
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in 2,6-Dicyanopyridine |
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Calculation was made here of the
nitrogen nqcc's in 2,6-dicyanopyridine on a structure optimized at the B3P86/6-31G(3d,3p)
level of theory. These nqcc's are shown in Tables 1 and 2.
Structure parameters are given in Table
3, atomic coordinates in Table 4, and rotational constants in Table 5. |
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In Tables 1 and 2, subscripts a,b,c
refer to the principal axes of the inertia tensor; 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. Pyridinic Nitrogen nqcc's in 2,6-Dicyanopyridine (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 |
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1.705 |
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Xbb |
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5.047 |
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Xcc |
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3.342 |
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ETA |
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0.324 |
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RSD |
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0.030 (1.3 %) |
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* ETA = (Xbb
- Xcc)/Xaa = (Xxx - Xyy)/Xzz. |
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Table 2. Cyano Nitrogen nqcc's in 2,6-Dicyanopyridine (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 |
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2.834 |
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Xbb |
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0.574 |
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Xcc |
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2.260 |
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Xab |
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2.865 |
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RSD |
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0.030 (1.3 %) |
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Xxx |
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2.204 |
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Xyy |
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2.260 |
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Xzz |
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4.464 |
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ETA |
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0.013 |
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Øz,a |
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29.63 |
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Øa,CN |
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29.16 |
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Øz,CN |
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0.46 |
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| Table 3. 2,6-Dicyanopyridine and Pyridine. Molecular structure parameters, ropt (Å
and degrees). |
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2,6-Dicyanopyridine |
Pyridine |
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N(1)C(2) |
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1.3332 |
1.3336 |
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C(2)C(3) |
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1.3971 |
1.3904 |
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C(3)C(4) |
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1.3863 |
1.3885 |
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C(2)C(7) |
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1.4388 |
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C(7)N(8) |
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1.1565 |
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C(3)H(3) |
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1.0831 |
1.0845 |
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C(4)H(4) |
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1.0840 |
1.0851 |
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C(6)N(1)C(2) |
116.68 |
117.03 |
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N(1)C(2)C(3) |
124.08 |
123.80 |
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C(2)C(3)C(4) |
118.13 |
118.44 |
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C(3)C(4)C(5) |
118.89 |
118.50 |
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N(1)C(2)C(7) |
116.68 |
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C(2)C(7)N(8) |
177.50 * |
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C(2)C(3)H(3) |
120.01 |
120.21 |
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* The CN tilt outward, each away from the other. |
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| Table 4. 2.6-Dicyanopyridine. Atomic coordinates, ropt. |
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a (Å) |
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b (Å) |
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N(1) |
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0.0 |
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0.7067 |
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C(2,6) |
± |
1.1348 |
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0.0068 |
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C(3,5) |
± |
1.1939 |
- |
1.3890 |
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C(4) |
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0.0 |
- |
2.0938 |
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C(7) |
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2.3594 |
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0.7620 |
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N(8) |
± |
3.3694 |
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1.3256 |
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H(3,5) |
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2.1539 |
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1.8905 |
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H(4) |
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0.0 |
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3.1777 |
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| Table 5. 2,6-Dicyanopyridine. Rotational Constants
(MHz). |
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Calc ropt |
Expt. |
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A |
2710.7 |
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B |
960.8 |
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C |
709.3 |
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Pyridine |
2,6-Difluoropyridine |
2,6-Dichloropyridine |
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2-Cyanopyridine |
2,6-Dimethylpyridine |
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3-Cyanopyridine |
4-Cyanopyridine |
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Table of Contents
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Molecules/Nitrogen |
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26DCNP.html |
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Last
Modified 17 Feb 2004 |
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