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C6F5Br |
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Bromine |
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Nuclear
Quadrupole Coupling Constants |
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in Bromopentafluorobenzene |
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Bromine nqcc tensors in C6F5Br were calculated here on an ropt
molecular structure given by PBE1PBE/6-31G(3d,3p)
optimization. These are shown below in Table 1. Structure
parameters are compared with C6H5Br in Table 3. Rotational constants are given in Table 4.
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In Table 1, subscripts a,b,c refer to principal axes of the inertia tensors. ETA = (Xbb - Xcc)/Xaa = (Xxx
- Xyy)/Xzz, where x,y,z refer to principal axes of the nqcc tensor. RSD
is the residual standard deviation of calibration of the B1LYP/TZV(3df,3p) model for calculation of the efg's/nqcc's. |
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Table 1. Bromine nqcc's in C6F5Br (MHz). Calculation was made on the PBE1PBE/6-31G(3d,3p) ropt structure. |
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Calc. |
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Expt.
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79Br |
Xaa |
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635.28 |
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Xbb |
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346.13 |
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Xcc |
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289.15 |
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ETA |
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0.0897 |
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RSD |
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1.58 (0.39 %) |
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81Br |
Xaa |
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530.76 |
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Xbb |
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289.18 |
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Xcc |
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241.57 |
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ETA |
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0.0897 |
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RSD |
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1.38 (0.40 %) |
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Table 2. C6X5Br, X = H, F. PBE1PBE/6-31G(3d,3p) molecular structure parameters (Å and degrees).
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X = F
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X = H
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C(1)Br |
1.8489 |
1.8765 |
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C(1)C(2) |
1.3893 |
1.3884 |
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C(2)C(3) |
1.3881 |
1.3897 |
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C(3)C(4) |
1.3884 |
1.3896 |
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C(2)X(2) |
1.3234 |
1.0835 |
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C(3)X(3) |
1.3233 |
1.0856 |
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C(4)X(4) |
1.3216 |
1.0852 |
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C(6)C(1)C(2) |
118.32 |
120.94 |
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C(1)C(2)C(3) |
121.18 |
119.26 |
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C(2)C(3)C(4) |
119.78 |
120.43 |
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C(3)C(4)C(5) |
119.66 |
119.68 |
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C(1)C(2)X(2) |
120.46 |
119.99 |
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C(2)C(3)X(3) |
120.25 |
119.44 |
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For further comparison, the PBE1PBE/6-31G(3d,3p) optimized molecular structure of benzene is CC =
1.3908 Å and CH = 1.0860 Å.
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Table 3. C6F579Br Rotational Constants (MHz).
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Calc /ropt |
Expt.
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A
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1034.0
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B
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499.1
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C
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336.6
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C6H5Br
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C6H5Cl
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C6F5Cl
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C6H5CN |
C6F5CN |
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Table of Contents |
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Molecules/Bromine |
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C6F5Br.html |
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Last
Modified 10 June 2014 |
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