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3,5-F2-C5H3N
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Nitrogen
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Nuclear
Quadrupole Coupling Constants |
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in
3,5-Difluoropyridine |
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Calculation was made of the
nitrogen nqcc's in 3,5-difluoropyridine on a
molecular structure given by B3P86/6-31G(3d,3p) optimization.
These are compared with the experimental vaules of Dijk et al. [1] in
Table 1. Structure parameters are given
in Table 2, atomic coordinates in Table 3, rotational constants in
Table 4, and quartic centrifugal distortion constants in Table 5.
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Subscripts a,b,c
refer to the principal axes of the inertia tensor; x,y,z to the
principal axes of the nqcc tensor. RMS is the root mean square
difference between calculated and experimental nqcc's. 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
3,5-Difluoropyridine (MHz). Calculation
was made on the B3P86/6-31G(3d,3p) ropt structure. |
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Calc. |
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Expt. [1]
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14N |
Xaa |
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1.509 |
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1.5163(10) *
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Xbb |
- |
5.041 |
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5.0349(8) *
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Xcc |
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3.532 |
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3.5187(8) *
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ETA ** |
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0.401 |
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RMS
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0.009 (0.28 %)
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RSD |
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0.030 (1.3 %) |
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* Calculated here from experimental
1.5(Xaa) = 2.2744(15) MHz and 0.25(Xbb - Xcc)
= -2.1384(3) MHz using Kisiel's program
QDIAG.f. |
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** ETA = (Xaa - Xcc)/Xbb
= (Xxx - Xyy)/Xzz. |
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| Table 2.
3,5-Difluoropyridine. Molecular structure parameters, ropt
and rs [1] (Å and degrees). |
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ropt
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rs |
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N(1)C(2) |
1.3301 |
1.338(1) |
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C(2)C(3) |
1.3881 |
1.377(6) |
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C(3)C(4) |
1.3831 |
1.387(3) |
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C(2)H(2) |
1.0861 |
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C(3)F(3) |
1.3366 |
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C(4)H(4) |
1.0828 |
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C(6)N(1)C(2) |
118.73 |
118.4(2) |
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N(1)C(2)C(3) |
121.73 |
121.5(5) |
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C(2)C(3)C(4) |
121.07 |
122.1(5) |
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C(3)C(4)C(5) |
115.68 |
114.5(4) |
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N(1)C(2)H(2) |
118.20 |
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C(2)C(3)F(3) |
119.57 |
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| Table 3.
3.5-Difluoropyridine. 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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1.7938 |
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C(2,6) |
± |
1.1444 |
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1.1159 |
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C(3,5) |
± |
1.1709 |
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0.2720 |
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C(4) |
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0.0 |
- |
1.0081 |
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F(3,5) |
± |
2.3457 |
- |
0.9093 |
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H(2,6) |
± |
2.0738 |
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1.6779 |
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H(4) |
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0.0 |
- |
2.0909 |
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| Table 4.
3,5-Difluoropyridine. Rotational Constants (MHz). |
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Calc ropt |
Expt. [1]
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A |
3875.3 |
3851.89218(7)
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B |
1791.6 |
1784.81604(5)
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C |
1225.2 |
1219.50447(4)
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Table
5. 3,5-Difluoropyridine. Quartic centrifugal distortion
constants (kHz). Calc = B3LYP/cc-pVTZ opt freq=vibrot
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Calc |
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Expt [1] |
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Delta_J
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0.0642
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0.0669(5)
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Delta_JK |
-
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0.0250
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0.0182(16)
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Delta_K |
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0.767
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0.761(3)
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delta_j |
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0.0222
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0.02301(18)
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delta_k |
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0.132
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0.1359(20)
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[1] C.W.
van Dijk, M.Sun, and J. van Wijngaarden, J.Mol.Spectrosc. 280,34(2012). |
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Pyridine |
2-Fluoropyridine |
2,3-Difluoropyridine |
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3-Fluoropyridine |
4-Fluoropyridine |
2,4-Difluoropyridine |
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3,4-Difluoropyridine |
2,6-Difluoropyridine |
2,5-Difluoropyridine |
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Table of Contents
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Molecules/Nitrogen |
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35DFP.html |
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Last
Modified 12 June 2012 |
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