David Osborne

David Osborne
Born	(1984-01-10)January 10, 1984
Residence	Athens, GA, United States
Nationality	United States
Scientific career
Fields	Gas-phase ion chemistry

David S. Osborne Jr. (born January 10, 1984) is an American chemist whose graduate research in gas-phase ion chemistry was carried out at the University of Georgia in Athens, Georgia. His work concerns the reactions and lifetimes of ionic and excited species relevant to planetary atmospheres and the interstellar medium, with a particular focus on the upper atmosphere of Saturn's moon Titan.

Biography

Osborne pursued doctoral studies in gas-phase ion chemistry at the University of Georgia under the direction of Nigel G. Adams. His dissertation examined the electron–ion dissociative recombination of substituted benzene analogs of relevance to the atmosphere of Titan.

Scientific contributions

Osborne's research measured electron–ion dissociative recombination (e-IDR) rate constants for organic molecules of interest to atmospheric and astrochemical modeling. Following the arrival of the Cassini spacecraft at Titan in 2004, the moon's atmosphere was found to contain large, complex polycyclic aromatic hydrocarbons, creating a need for laboratory kinetic data with which to model the observed chemistry. Because rate-constant data were not readily available for larger compounds such as naphthalene or for oxygen-containing compounds such as 1,4-dioxane and furan, Osborne and colleagues measured these values using the University of Georgia's Variable Temperature Flowing Afterglow apparatus. Such laboratory measurements support the chemical modeling required to reconcile in situ mass spectra recorded by Cassini during its passes through Titan's ionosphere with those predicted by models.

His studies also examined how functional-group substitution affects e-IDR rate constants for benzene analogs, relating the observed trends to the electron-withdrawing or electron-donating character of the substituents as expressed by Hammett σ_para constants.

Selected works

• Osborne, D. S. Jr.; Dotan, I.; Adams, N. G. (2014). "Trends in electron–ion dissociative recombination of benzene analogs with functional group substitutions: Positive Hammett σ_para constants." International Journal of Mass Spectrometry 360: 24–27.
• Osborne, D. S. Jr.; Lawson, P. A.; Adams, N. G.; Dotan, I. (2014). "Trends in electron–ion dissociative recombination of benzene analogs with functional group substitutions: Negative Hammett σ_para values." Icarus.

External links

• "Trends in electron–ion dissociative recombination of benzene analogs with functional group substitutions: Positive Hammett σpara constants" (ScienceDirect)
• "Trends in electron–ion dissociative recombination of benzene analogs with functional group substitutions: Negative Hammett σpara values" (ScienceDirect)