title: Formation of a unique ansa-metallocene framework by intramolecular photochemical [2+2] cycloaddition of bis(2-alkenylindenyl)zirconium complexes.
authors.affiliation: Organisch-Chemisches Institut, Universität Münster, Corrensstrasse 40, 48149 Muenster, Germany.
authors.forename: Wan-Li
authors.initials: WL
authors.lastname: Nie
authors.forename: Gerhard
authors.initials: G
authors.lastname: Erker
authors.forename: Gerald
authors.initials: G
authors.lastname: Kehr
authors.forename: Roland
authors.initials: R
authors.lastname: Fröhlich