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 1 forms 6,3-connected 2-D coordination polymers on reaction with silver(I). Compounds {[Ag(1)](PF6)center dot 2(CH3NO2)}(n) 2 and {[Ag(1)](ClO4)center dot 2(CH3NO2)}(n), 3, which are the first coordination polymers of 1, readily crystallize from solutions of the silver salt and 1 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 1. The anions are in close proximity to the electron-deficient [3]-radialene core of 1, forming weak anion-pi interactions.