Photochemical And Spectroscopic Studies Of Pah Motion At Interfaces
Photochemical and spectroscopic studies of PAH, e.g., anthracene, at silica gel interfaces with air and organic solvents were conducted and revealed that photochemical dimerization reactions can occur at lower than anticipated concentrations in solid-solvent slurries and well-below monolayer coverage at solid-air interfaces. The rate (or efficiency) of anthracene dimerization in dilute homogeneous solutions (< 1 × 10-2 M) was proportional to the anthracene concentration. In the slurry, ≈ 70% of the anthracene was adsorbed on the silica surface. The increase in photochemical dimerization rate was attributed to the increased anthracene concentration on the surface and in the immediate vicinity of the surface where anthracene was dynamically exchanging between the surface and solution. When PAH were adsorbed at silica-air interfaces, in the absence of any solvent, molecule translation on the surface was fairly slow. Similar dimerization reactions were observed for acenaphthylene and tetracene at low surface coverages. Rotational diffusion rates were determined for silica-attached 1-hydroxypyrene at the solid/air interface through time-dependant fluorescence anisotropy measurements. This is an abstract of a paper originally presented at the 225th ACS National Meeting (New Orleans, LA 3/23-27/2003).
ACS, Division of Environmental Chemistry - Preprints of Extended Abstracts
Number of Pages
Article; Proceedings Paper
Source API URL
Sigman, Michael E.; Dabestani, Reza; and Hagaman, Edward, "Photochemical And Spectroscopic Studies Of Pah Motion At Interfaces" (2003). Scopus Export 2000s. 1384.