Photochemistry of (OCS)n- cluster ions

Andrei M Sanov, Sreela Nandi, Kenneth D. Jordan, W. Carl Lineberger

Research output: Contribution to journalArticle

31 Citations (Scopus)

Abstract

We report the photochemistry of (OCS)n- cluster ions following 395 nm (n=2-28) and 790 nm (n=2-4) excitation. In marked contrast to (CO2)n-, extensive bond breaking and rearrangement is observed. Three types of ionic products are identified: S2-(OCS)k, S-(OCS)k/OCS2-(OCS)k-1, and (OCS)k-. For n<16, 395 nm dissociation is dominated by S2--based fragments, supporting the theoretical prediction of a cluster core with a C2v(OCS)2- dimer structure and covalent C-C and S-S bonds. A shift in the branching ratio in favor of S--based products is observed near n=16, consistent with an opening of the photodissociation pathway of OCS- core-based clusters. These monomer-based cluster ions may coexist with the dimer-based clusters over a range of n, but electron detachment completely dominates photodissociation as long as their vertical electron detachment energy, increasing with addition of each solvent molecule, is less then the photon energy. An (OCS)2- conformer of C2 symmetry with a covalent C-C bond is believed to be responsible for 790 nm dissociation of (OCS)2-, yielding primarily OCS- products. The yield of OCS-, and thus the importance of the C2 form of (OCS)2- cluster core, decreases with increasing n, perhaps due to more favorable solvation of the C2v form of (OCS)2- and/or a solvent-induced increase in the rate of interconversion of conformers. The (OCS)k- products observed in 395 nm photodissociation of the larger (n≥7) clusters are attributed to photofragment caging. Formation and dissociation mechanisms of clusters with different core types are discussed. The photochemical properties of (OCS)n- are compared to those of the isovalent (CO2)n- and (CS2)n- species.

Original languageEnglish (US)
Pages (from-to)1264-1270
Number of pages7
JournalThe Journal of Chemical Physics
Volume109
Issue number4
DOIs
StatePublished - 1998
Externally publishedYes

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Photodissociation
Photochemical reactions
photochemical reactions
Ions
Dimers
ions
Electrons
Solvation
photodissociation
dissociation
products
Photons
Monomers
detachment
Molecules
dimers
solvation
electrons
monomers
fragments

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Cite this

Sanov, A. M., Nandi, S., Jordan, K. D., & Lineberger, W. C. (1998). Photochemistry of (OCS)n- cluster ions. The Journal of Chemical Physics, 109(4), 1264-1270. https://doi.org/10.1063/1.476677

Photochemistry of (OCS)n- cluster ions. / Sanov, Andrei M; Nandi, Sreela; Jordan, Kenneth D.; Lineberger, W. Carl.

In: The Journal of Chemical Physics, Vol. 109, No. 4, 1998, p. 1264-1270.

Research output: Contribution to journalArticle

Sanov, AM, Nandi, S, Jordan, KD & Lineberger, WC 1998, 'Photochemistry of (OCS)n- cluster ions', The Journal of Chemical Physics, vol. 109, no. 4, pp. 1264-1270. https://doi.org/10.1063/1.476677
Sanov, Andrei M ; Nandi, Sreela ; Jordan, Kenneth D. ; Lineberger, W. Carl. / Photochemistry of (OCS)n- cluster ions. In: The Journal of Chemical Physics. 1998 ; Vol. 109, No. 4. pp. 1264-1270.
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