Coordination Networks with Carborane Anions: Ag(I) and Nitrogen Bridging Ligands

Abstract

New crystalline coordination networks based on Ag(i) and N-bridging ligands — pyrazine (pyz), 4,4′-bipyridine (bpy), and 2,3-bis-(2-pyridyl)pyrazine (bppz) — incorporating carborane monoanions (CB11H12)− or [Co(C2B9H11)2]− were isolated and characterized using single crystal X-ray diffraction, microanalysis, and infrared spectroscopy. All the complexes with the bpy and bppz ligands reveal 1D coordination infinite chains involving the Ag(i) and the ligands, and layered extended structures with rows of carborane anions between the layers of chains. Interestingly, two polymorphs of the complex [Ag(bpy)(CH3CN)][Co(C2B9H11)2] were observed. The complex [Ag(pyz)(CH3CN)2][Co(C2B9H11)2] shows a 1D coordination polymer, while the pyz complex with the smaller carborane anion {[Ag(pyz)](CB11H12)} exhibits a 3D coordination network structure with four Ag···H−B interactions between the silver centre and carborane anions.