title: Capturing the missing [AgF2](-) anion within an Ru2(III/III) dimeric dumbbell complex.
abstract: The complex {[Ru2(ap)4]2[AgF2]}[BF4]3 ({2}[BF4]3, ap = 2-anilinopyridine), containing the [AgF2](-) anion ligated to two [Ru2](6+) cores, is prepared, characterized, and compared to dimeric dumbbell-type structures, monomeric Ru2 structures, as well as the known set of dihalo coinage-metalate anions. X-ray crystallography indicates that the Ru-Ru and Ru-F distances are rather short, 2.2835(3) Å and 2.054(1) Å, respectively, while the Ag-F distance of 2.274(1) Å is longer than that calculated for the free/un-ligated anion. Cyclic voltammetry in dichloromethane indicates that, while some of {2}(3+) breaks apart into an [Ru2(ap)4F](+) ([3](+)) monomer in solution, the remaining dimer has a single reversible two-electron redox feature for the Ru2(6/5+) couple that is at a lower potential than that of [3](+). This is one of the few examples of a ligated dihalo coinage-metalate, and it is the first example of a coinage metal difluoride anion, either free or ligated.
authors.affiliation: Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, WI 53706, USA. berry@chem.wisc.edu.
authors.forename: Amanda R
authors.initials: AR
authors.lastname: Corcos
authors.forename: John F
authors.initials: JF
authors.lastname: Berry
mesh_terms: D000838:Anions / Q000737:chemistry; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry*; D018360:Crystallography, X-Ray; D019281:Dimerization; D055664:Electrochemical Techniques; D005459:Fluorides / Q000737:chemistry*; D008968:Molecular Conformation; D012428:Ruthenium / Q000737:chemistry*; D018030:Silver Compounds / Q000737:chemistry*
chemical_list: D000838:Anions; D056831:Coordination Complexes; D018030:Silver Compounds; C105022:silver fluoride; D012428:Ruthenium; D005459:Fluorides