2-D Coordination Polymers of Hexa(4-cyanophenyl)[3]-radialene and Silver(I): Anion···π-Interactions and Radialene C−H···Anion Hydrogen Bonds in the Solid-State Interactions of Hexaaryl[3]-radialenes with Anions

As part of our studies of ligands containing an electron-deficient [3]-radialene core we discovered that the hexadentate ligand hexa(4-cyanophenyl)[3]-radialene <b>1</b> forms 6,3-connected 2-D coordination polymers on reaction with silver(I). Compounds {[Ag(<b>1)</b>](PF<sub>6</sub>)·2(CH<sub>3</sub>NO<sub>2</sub>)}<sub><i>n</i></sub> <b>2</b> and {[Ag(<b>1)</b>](ClO<sub>4</sub>)·2(CH<sub>3</sub>NO<sub>2</sub>)}<sub><i>n</i></sub> <b>3</b>, which are the first coordination polymers of <b>1</b>, readily crystallize from solutions of the silver salt and <b>1</b> in noncoordinating nitromethane solvent and were characterized by X-ray crystallography. In these structures the ligand is hypodentate, coordinating only through four nitrile N-donors to act as a 3-connecting center. The distorted tetrahedral silver also acts as a 3-connecting center. In the extended structure the anions lie in pockets above and below the [3]-radialene core of the ligands, forming moderate and weak hydrogen bonds with four different molecules of <b>1</b>. The anions are in close proximity to the electron-deficient [3]-radialene core of <b>1</b>, forming weak anion−π interactions.