Wavelength dependent photochemical decarbonylation of H[sub 2]Ru[sub 4](CO)[sub 13] to form coordinatively unsaturated H[sub 2]Ru[sub 4](CO)[sub 12] in solid matrices at 77 K: A model for the photoreaction postulated to form H[sub 2]Ru[sub 4](CO)[sub 12] on the surface of silica

Journal Article · Thu Jan 21 04:00:00 EST 1993 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100105a007· OSTI ID:6304470

Yamamoto, Sadaaki; Nitta, Atsuhiko ^[1]; Asakura, Kiyotaka; Kuroda, Haruo ^[2]; Mochida, Kunio ^[3]

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1. Mitsui Toatsu Chemicals Inc., Yokohama (Japan)
2. Univ. of Tokyo (Japan)
3. Gakushuuin Univ., Tokyo (Japan)

The photochemical reaction of dihydrotetraruthenium tridecacarbonyl, H[sub 2]Ru[sub 4](CO)[sub 13], was investigated by UV-visible and FT-IR absorption spectroscopies at 77 K in both a 3-methylpentane matrix and a polystyrene film. Upon irradiation at 313 nm, H[sub 2]Ru[sub 4](CO)[sub 13] undergoes clean CO dissociation yielding selectively a single product. One CO is released from each parent carbonyl cluster that reacts. Upon warming to 298 K, the efficient recombination of CO trapped in nearby sites with the photoproduct completely regenerates the parent cluster H[sub 2]Ru[sub 4](CO)[sub 13]. From these and other results, the photoproduct is identified as the coordinatively unsaturated cluster H[sub 2]Ru[sub 4](CO)[sub 12]. The photoinduced CO dissociation is dependent on the excitation wavelength, which can be interpreted in terms of the electronic structure of the corresponding excited states. At 298 K, UV-visible light irradiation does not produce any changes in the absorption spectra irrespective of the excitation wavelength. This can be attributed to geminate recombination in which released CO efficiently recombines with H[sub 2]Ru[sub 4](CO)[sub 12]. The UV-visible and IR spectra of matrix isolated H[sub 2]Ru[sub 4](CO)[sub 12] agree with those of the photoproduct formed when H[sub 2]Ru[sub 4](CO)[sub 13] adsorbed on the surface of silica is irradiated. This spectral agreement allows the photoproduct on silica to be assigned as H[sub 2]Ru[sub 4](CO)[sub 12], which supports the previous postulate about the photochemical process occurring when H[sub 2]Ru[sub 4](CO)[sub 13] absorbed on the surface of silica is irradiated. 14 refs., 5 figs.

• OSTI ID: 6304470
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 97:3; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
ABSORPTION
ABSORPTION SPECTROSCOPY
CARBONYLS
CHEMICAL REACTIONS
DISSOCIATION
ELECTRONIC STRUCTURE
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EXCITATION
EXCITED STATES
FILMS
HYDROGEN COMPOUNDS
IRRADIATION
MATERIALS
MATRICES
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PETROCHEMICALS
PETROLEUM PRODUCTS
PHOTOCHEMICAL REACTIONS
PLASTICS
POLYMERS
POLYOLEFINS
POLYSTYRENE
POLYVINYLS
RECOMBINATION
REFRACTORY METAL COMPOUNDS
RUTHENIUM COMPOUNDS
SORPTION
SPECTROSCOPY
SYNTHETIC MATERIALS
TRANSITION ELEMENT COMPOUNDS