title: Two frustrated, bitetrahedral single-molecule magnets.
abstract: Two unusual mixed-valent {MnIII6MnII} bitetrahedra display frustrated magnetic exchange, leading to S = 13/2 +/- 1 and 11/2 +/- 1 ground states and slow magnetization relaxation.
authors.affiliation: School of Chemistry, The University of Edinburgh, Edinburgh, UK.
authors.forename: Constantinos J
authors.initials: CJ
authors.lastname: Milios
authors.forename: Ian A
authors.initials: IA
authors.lastname: Gass
authors.forename: Alina
authors.initials: A
authors.lastname: Vinslava
authors.forename: Laura
authors.initials: L
authors.lastname: Budd
authors.forename: Simon
authors.initials: S
authors.lastname: Parsons
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Wernsdorfer
authors.forename: Spyros P
authors.initials: SP
authors.lastname: Perlepes
authors.forename: George
authors.initials: G
authors.lastname: Christou
authors.forename: Euan K
authors.initials: EK
authors.lastname: Brechin