Plattenspieler trans-Orbitale: Unterschied zwischen den Versionen

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According to our DFT-calculations (B3LYP/6-311+G*) the ''n'' and 𝜋 orbitals of the diazapyridine unit differ in the ''cis'' and ''trans'' configuration, similar to the parent azobenzene. The highest occupied orbital with coefficients located at the azopyridine unit (n type orbital) is considerably higher in energy for the ''cis'' as compared to the ''trans'' isomer (E<sub>cis</sub>=-6.19 eV(MO=219)), (E<sub>trans</sub>=-6.53 eV(MO=216)).
According to our DFT-calculations (B3LYP/6-311+G*) the ''n'' and 𝜋 orbitals of the diazapyridine unit differ in the ''cis'' and ''trans'' configuration, similar to the parent azobenzene. The highest occupied orbital with coefficients located at the azopyridine unit (n type orbital) is considerably higher in energy for the ''cis'' as compared to the ''trans'' isomer (E<sub>cis</sub>=-6.19 eV(MO=219)), (E<sub>trans</sub>=-6.53 eV(MO=216)).
We therefore identify the signal at 2eV in the STS spectrum of the ''cis'' isomer as the lone pair orbital mainly located at the azo-group of the azopyridine unit (MO=219). The lone pair orbitals at the azo group of the ''cis'' isomer have their maximum elevation pointing away from the surface and thus are exposed to the STM tip which gives rise to a large signal.

Version vom 6. August 2009, 14:51 Uhr

Struktur

Orbitale

DOS-Spektrum

Plattenspieler trans DOS.png STS-Spektrum Plattenspieler.png

LUMOs

Plattenspieler trans LUMOs.png

HOMOs

Plattenspieler trans HOMOs.png

Orbitalenergien

231     L+9     -0.65   A
230     L+8     -0.7    A
229     L+7     -0.74   A
228     L+6     -0.98   A
227     L+5     -1.15   A
226     L+4     -1.17   A
225     L+3     -1.5    A
224     L+2     -2.46   A
223     L+1     -2.49   A
222     LUMO    -2.85   A
221     HOMO    -5.33   A
220     H-1     -5.46   A
219     H-2     -6.16   A
218     H-3     -6.19   A
217     H-4     -6.39   A
216     H-5     -6.53   A
215     H-6     -6.76   A
214     H-7     -6.79   A
213     H-8     -6.87   A
212     H-9     -6.96   A
211     H-10    -6.99   A

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Interpretation of STS-spectra

According to our DFT-calculations (B3LYP/6-311+G*) the n and 𝜋 orbitals of the diazapyridine unit differ in the cis and trans configuration, similar to the parent azobenzene. The highest occupied orbital with coefficients located at the azopyridine unit (n type orbital) is considerably higher in energy for the cis as compared to the trans isomer (Ecis=-6.19 eV(MO=219)), (Etrans=-6.53 eV(MO=216)).

We therefore identify the signal at 2eV in the STS spectrum of the cis isomer as the lone pair orbital mainly located at the azo-group of the azopyridine unit (MO=219). The lone pair orbitals at the azo group of the cis isomer have their maximum elevation pointing away from the surface and thus are exposed to the STM tip which gives rise to a large signal.