Photo-induced inter-conversion reactions between atoms and small aggregates of chromium trapped in argon matrices

Derouault, J.; Dalibart, M.

doi:10.1007/bf01448294

Cited by 3 publications

(9 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The work on transition metal clusters, with emphasis on the determination of force constants and thus vibrational spectra, has been reviewed by Lombardi and Davis . Transition metal dimers have been generated in inert gas matrices for all transition metals except for Tc, Os, Ir, Pd, Zn, Cd, and Hg . For the dimers of Zn, Cd, and Hg, gas‐phase studies confirm an extremely weak bonding.…”

Section: Metal Atom Clustersmentioning

confidence: 99%

See 1 more Smart Citation

Metal Cluster Models for Heterogeneous Catalysis: A Matrix‐Isolation Perspective

Hübner

Himmel

2018

Chemistry A European J

View full text Add to dashboard Cite

Metal cluster models are of high relevance for establishing new mechanistic concepts for heterogeneous catalysis. The high reactivity and particular selectivity of metal clusters is caused by the wealth of low-lying electronically excited states that are often thermally populated. Thereby the metal clusters are flexible with regard to their electronic structure and can adjust their states to be appropriate for the reaction with a particular substrate. The matrix isolation technique is ideally suited for studying excited state reactivity. The low matrix temperatures (generally 4-40 K) of the noble gas matrix host guarantee that all clusters are in their electronic ground-state (with only a very few exceptions). Electronically excited states can then be selectively populated and their reactivity probed. Unfortunately, a systematic research in this direction has not been made up to date. The purpose of this review is to provide the grounds for a directed approach to understand cluster reactivity through matrix-isolation studies combined with quantum chemical calculations.

show abstract

Section: Metal Atom Clustersmentioning

confidence: 99%

“…Reactions of metal clusters have been studied with O 2 , N 2 , CO, N 2 O and H 2 O . There are only a few examples for reactions of clusters with organic molecules …”

Section: Metal Atom Clustersmentioning

confidence: 99%

Metal Cluster Models for Heterogeneous Catalysis: A Matrix‐Isolation Perspective

Hübner

Himmel

2018

Chemistry A European J

View full text Add to dashboard Cite

show abstract

“…Keeping possible fragmentation in mind, the comparison allows an assignment of the Cr 2 + y 5 P 3 a 5 S 2 signal ( Fig. [50][51][52] The detection of Cr 3 + and Cr 4 + therefore suggests that the Cr 2 dissociation process and surface migration of one atom is not disturbed by the presence of a further Cr atom or dimer in the droplet. We mention that in addition to the Cr + Cr + -Cr 2 + recombination, another recombination path is possible, although unlikely.…”

Section: Separation To a Surface Located A 5 S 2 And A Solvated A 7 Smentioning

confidence: 99%

“…For the strongly bound Cr 2 singlet ground state (binding energy = 1.42 eV (11 450 cm À1 ) 38 ), the majority of droplets are expected to survive the formation for a size distribution maximum of N = 6300 and an energy of 5 cm À1 dissipated per evaporated He atom. 40,51,52,55,56 41,43,54 Cr 2 excitation spectra in other solid rare gas matrices yield usually shifted and broadened spectral features, but cannot provide a consistent picture about the magnitude of the shift.…”

Section: Cr 2 Excitation Spectrummentioning

confidence: 99%

“…50 This dimerization effect controls the cluster growth up to Cr 11 , yielding similarities between the ground state photoabsorption spectra of dimers and small chromium clusters. [50][51][52] The detection of Cr Now we turn to the Cr 2 A 1 S u + ' X 1 S g + excitation band, in particular to the broad band stretching from 21 500 to 22 750 cm À1 that is present in the Cr + signal of the one-color REMPI scheme, shown as black curve in Fig. 2(a).…”

Section: Cr 234mentioning

confidence: 99%

See 1 more Smart Citation

Photoinduced molecular dissociation and photoinduced recombination mediated by superfluid helium nanodroplets

Kautsch

Koch

Ernst

2015

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

We have investigated photoinduced chemical reaction dynamics of cold, isolated Cr2 molecules in helium nanodroplets (HeN), exploiting the quantum state specific spatial separation of solvated and surface locations on the droplet. The molecules are excited to achieve dissociation to a ground state (a(7)S3) and a metastable state (a(5)S2) atom. State specific spatial separation, in combination with efficient translational cooling to avoid ejection, causes the ground state atom to be solvated inside the droplet while the metastable atom migrates to the surface. A barrier between the two reactants formed by the HeN prevents recombination. We apply a resonance-enhanced multiphoton ionization scheme including the y(5)P°(1,2,3) <-- a(5)S(2) transition of the surface atom as well as a two-laser scheme including the y(7)P°(2,3,4) <-- a(7)S(3) transition of the solvated atom in order to verify the locations and separation of the dissociation products. Furthermore, ionization of the a(5)S2 surface atom triggers solvation followed by geminate recombination with the a(7)S3 atom, which is verified by the detection of Cr2(+) molecular ions. For small Cr clusters, our results indicate that they may be composed of chromium dimers that exhibit the same dissociation behavior.

show abstract

Resonance Raman Spectroscopy of Mass Selected Chromium Trimers in an Argon Matrix

Fang

Davis

et al. 2001

J. Phys. Chem. A

View full text Add to dashboard Cite

The resonance Raman spectra of mass-selected chromium trimers (Cr 3 ) in argon matrixes have been obtained. Five resonance Raman transitions were observed between 450 and 690 nm. Four of them are assigned to a totally symmetric (a 1 ′) vibrational progression, from which we obtain a ground-state harmonic frequency of ω e ) 432.2 cm -1 with ω e x e ) 16.3 cm -1 . The other Raman line, observed at 302.0 cm -1 , is assigned to the degenerate bending motion V 2 (e′) of the triatomic metal cluster. The geometry of the ground state is that of an equilateral triangle (D 3h ). These results provide a value of the stretching force constant of k e ) 1.91 mdyne/Å and a spectroscopic atomization energy of 0.36 eV.

show abstract

Photo-induced inter-conversion reactions between atoms and small aggregates of chromium trapped in argon matrices

Cited by 3 publications

References 8 publications

Metal Cluster Models for Heterogeneous Catalysis: A Matrix‐Isolation Perspective

Metal Cluster Models for Heterogeneous Catalysis: A Matrix‐Isolation Perspective

Photoinduced molecular dissociation and photoinduced recombination mediated by superfluid helium nanodroplets

Resonance Raman Spectroscopy of Mass Selected Chromium Trimers in an Argon Matrix

Contact Info

Product

Resources

About