Coordination Polymers with Carborane Anions:  Silver Dinitrile Complexes

Crystalline materials have been isolated and characterized from mixing the silver carborane salts Ag(CB11H12) or Ag[Co(C2B9H11)2] with nitrile ligands, either terminal acetonitrile or potentially bridging alkanedinitriles. Most of the complexes showed B−H···Ag interactions between the silver center and carborane anion. [Ag(acetonitrile)2(CB11H12)] has a hexagonal network structure. [Ag(malonitrile)2(CB11H12)] is a discrete dimeric complex, while [Ag4(succinonitrile)5(CB11H12)4], [Ag(glutaronitrile)2][Co(C2B9H12)2], and {Ag(glutaronitrile)[Co(C2B9H11)2]} all show coordination chain structures. The carborane anions in {Ag(adiponitrile)[Co(C2B9H11)2]} bridge between Ag centers to give a 3D CdSO4-related coordination polymer. The structure of [Ag(malonitrile)2](BF4) was also determined to have an unusual chiral diamondoid structure with a skewed 2-fold interpenetration.