Determining the Quantum Efficiency for Activation of an Organometallic Photoinitiator for Cationic Polymerization: An Experiment for the Physical or Inorganic Chemistry Laboratory

Autor/inn/en	Hayes, David M.; Mahar, Maura; Schnabel, R. Chris; Shah, Paras; Lees, Alistair J.; Jakubek, Vladimir
Titel	Determining the Quantum Efficiency for Activation of an Organometallic Photoinitiator for Cationic Polymerization: An Experiment for the Physical or Inorganic Chemistry Laboratory
Quelle	In: Journal of Chemical Education, 84 (2007) 9, S.1483-1485 (3 Seiten)Infoseite zur Zeitschrift PDF als Volltext Verfügbarkeit
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	0021-9584
Schlagwörter	Inorganic Chemistry; Laboratory Experiments; Science Experiments; Science Instruction; College Science; Science Laboratories; Scientific Principles + Suchen Sie Ihr Suchwort? Anorganische Chemie; Laboratory work; Laborarbeit; Teaching of science; Science education; Natural sciences Lessons; Naturwissenschaftlicher Unterricht
Abstract	We present a new laboratory experiment on the photochemistry of organometallic [eta][superscript 5],[eta][superscript 6]-mixed-sandwich compounds, which is suitable for both the physical chemistry and inorganic chemistry laboratory. Specifically, students use 1,10-phenanthroline to trap the intermediate formed when [CpFe(isopropylbenzene)]PF[subscript 6] is photolyzed with 458 nm light from an argon-krypton laser. Using quantitative UV-vis spectroscopy students then determine the quantum yield of arene ring displacement from the mixed-sandwich complex. The photogenerated intermediate, [CpFe(solvent)[subscript 3]][superscript +] is an efficient initiator for the polymerization of epoxides, dicyanate esters, pyrrole, styrene, dioxolenes, and acrylates. The efficiency with which the intermediate is photochemically formed is therefore an important property in determining its commercial utility. Although the experiment can easily be done in one 3-4 hour laboratory period, it readily lends itself to broadening into a multi-week research project. In this mode, students can examine how changing the nature of the solvent and the irradiation wavelength affect the quantum yield of reaction. Such information can be used to reveal the role of the solvent in the reaction and the electronic excited states from which reaction occurs. Furthermore, in the inorganic laboratory, students could be asked to synthesize [CpFe(isopropylbenzene]PF[subscript 6] before looking at its photochemical behavior, thus gaining experience in working under air-free conditions. (Contains 1 scheme, 2 figures and 1 table.) (As Provided).
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Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2017/4/10