title: Environmental effects on the aggregation of some xanthene dyes used in lasers.
abstract: The effect of solvents, halo substituents and surfactants on the aggregation of xanthene dyes (fluorescein and eosin Y) has been investigated. It has been found that polar protic solvents promote the aggregation of both the dyes while polar aprotic solvents hinder the aggregation process. Apolar solvents can disintegrate the aggregates previously formed in aqueous medium. The nature of the driving forces for aggregation in the two dyes is different. Surfactants bearing charge opposite to the dye molecules facilitate aggregation. These observations bear direct relevance to the possible use of fluorescein and eosin Y as quantum yield standards, photosensitizers, laser dyes and biological labels.
authors.affiliation: Department of Chemistry, University of Kalyani, Kalyani 741235, Nadia, West Bengal, India. swati@klyuniv.ernet.in
authors.forename: Swati
authors.initials: S
authors.lastname: De
authors.forename: Susmita
authors.initials: S
authors.lastname: Das
authors.forename: Agnishwar
authors.initials: A
authors.lastname: Girigoswami
mesh_terms: D000042:Absorption; D004396:Coloring Agents / Q000494:pharmacology; D019281:Dimerization; D004146:Dioxanes / Q000737:chemistry; D004573:Electrolytes; D004801:Eosine Yellowish-(YS) / Q000737:chemistry; D019793:Fluorescein / Q000737:chemistry; D007834:Lasers; D046911:Macromolecular Substances; D015233:Models, Statistical; D016011:Normal Distribution; D017319:Photosensitizing Agents / Q000494:pharmacology; D012997:Solvents; D013053:Spectrophotometry / Q000379:methods*; D013501:Surface-Active Agents / Q000737:chemistry / Q000494:pharmacology*; D013696:Temperature; D013997:Time Factors; D014966:Xanthenes / Q000737:chemistry*
chemical_list: D004396:Coloring Agents; D004146:Dioxanes; D004573:Electrolytes; D046911:Macromolecular Substances; D017319:Photosensitizing Agents; D012997:Solvents; D013501:Surface-Active Agents; D014966:Xanthenes; D004801:Eosine Yellowish-(YS); D019793:Fluorescein