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V
3
O
-
∆
E
(eV)
2S + 1= 1
2S + 1= 3
2S + 1= 5
1.815 Å
2.317 Å
0.91
1.825 Å
2.069 Å
0.25
1.805 Å
2.040 Å
0.0
FIGURE 9.19
Ground-state. and. low-lying. structures. of. V
3
O
−
. clusters.. Bond. lengths. are.
in.Å.and.energy.differences.are.in.eV..(Reprinted.from.Calaminici,.P..et.al.,.
J. Chem. Phys
.,.
118(11),.March.15,.4913,.2003..With.permission.)
ground-state.structure.of.the.anionic.system..The.equilibrium.geometries.of.both.
ground-state. structures. are. very. similar. (see. Figures. 9.18. and. 9.19).. A. triplet.
3
B
2
.
state.is.found.0.25.eV.above.the.anionic.ground-state.structure..Depending.on.the.
coordinate.system.orientation,.this.structure.could.be.also.assigned.as.a.
3
B
1
.state,.
which. has. been. proposed. as. the. anionic. ground-state. structure. in. the. literature.
[128]..A.planar.C
2v
.structure.in.the.quintet.PES.is.found.at.0.91.eV.above.the.anionic.
ground.state.(Figure.9.19).
In.order.to.further.characterize.the.optimized.ground-state.structures.of.V
3
O.and.
V
3
O
−
,.the.harmonic.vibrational.frequencies.have.been.calculated..The.results.of.the.
frequencies.calculated.for.the.ground-state.structures,.the.assignment.of.each.nor-
mal.mode,.and.its.symmetry.are.collected.in.Table.I.of.Ref..[183]..The.calculated.
atomization. energy. of. V
3
O. is. −13.45.eV. [183].. The. binding. energy. of. the. oxygen.
atom. on. the. vanadium. trimer. is. −8.77.eV. [183].. The. calculated. adiabatic. electron.
afinity. is. equal. to. 1.30.eV. [183].. This. value. is. in. very. good. agreement. with. the.
experimental.value.of.1.21.±.0.008.eV.from.negative.ion.photoelectron.spectroscopy.
[128]..From.the.harmonic.vibrational.frequencies.of.the.ground-state.structures.and.
the. corresponding. normal. mode. vectors,. we. calculated. harmonic. Franck-Condon.
factors.and.simulated.the.experimental.negative.ion.photoelectron.spectra.of.V
3
O..
The.reliability.of.the.ground-state.assignment.was.therefore.proven.by.the.simulation.
of.the.experimental.negative.ion.photoelectron.spectrum.[184].
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