title: Molecular Polyarsenides of the Rare-Earth Elements.
abstract: Reduction of [Cp*Fe(η(5)-As5)] with [Cp''2Sm(thf)] (Cp''=η(5)-1,3-(tBu)2C5H3) under various conditions led to [(Cp''2Sm)(μ,η(4):η(4)-As4)(Cp*Fe)] and [(Cp''2Sm)2As7(Cp*Fe)]. Both compounds are the first polyarsenides of the rare-earth metals. [(Cp''2Sm)(μ,η(4):η(4)-As4)(Cp*Fe)] is also the first d/f-triple decker sandwich complex with a purely inorganic planar middle deck. The central As4(2-) unit is isolobal with the 6π-aromatic cyclobutadiene dianion (CH)4(2-). [(Cp''2Sm)2As7(Cp*Fe)] contains an As7(3-) cage, which has a norbornadiene-like structure with two short As-As bonds in the scaffold. DFT calculations confirm all the structural observations. The As-As bond order inside the cyclo As4 ligand in [(Cp''2Sm)(μ,η(4):η(4)-As4)(Cp*Fe)] was estimated to be in between an As-As single bond and a formally aromatic As4(2-) system.
authors.affiliation: Institute of Inorganic Chemistry, Karlsruhe Institute of Technology, Engesserstrasse 15, 76131, Karlsruhe, Germany.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Arleth
authors.affiliation: Institute of Inorganic Chemistry, Karlsruhe Institute of Technology, Engesserstrasse 15, 76131, Karlsruhe, Germany.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Gamer
authors.affiliation: Institute of Inorganic Chemistry, Karlsruhe Institute of Technology, Engesserstrasse 15, 76131, Karlsruhe, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Köppe
authors.affiliation: Institute of Inorganic Chemistry, Karlsruhe Institute of Technology, Engesserstrasse 15, 76131, Karlsruhe, Germany.|Nikolaev Institute of Inorganic Chemistry SB RAS, Prosp. Lavrentieva 3, 630090, Novosibirsk, Russia.|Novosibirsk State University, Pirogova str. 2, 630090, Novosibirsk, Russia.
authors.forename: Sergey N
authors.initials: SN
authors.lastname: Konchenko
authors.affiliation: Institute of Inorganic Chemistry, University of Regensburg, 93040, Regensburg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Fleischmann
authors.affiliation: Institute of Inorganic Chemistry, University of Regensburg, 93040, Regensburg, Germany.
authors.forename: Manfred
authors.initials: M
authors.lastname: Scheer
authors.affiliation: Institute of Inorganic Chemistry, Karlsruhe Institute of Technology, Engesserstrasse 15, 76131, Karlsruhe, Germany. roesky@kit.edu.
authors.forename: Peter W
authors.initials: PW
authors.lastname: Roesky
keywords: arsenides; lanthanides; polyarsenide; samarium; triple-decker sandwich complex