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

Abstract

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)](PF 6 ) · 2(CH 3 NO 2 )} n 2 and {[Ag(1)](ClO 4 ) · 2(CH 3 NO 2 )} 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-π interactions.

Fluorescent hexaaryl- and hexa-heteroaryl[3]radialenes: Synthesis, structures, and properties

“…The coordination chemistry of hexaaryl- and hexapyridyl[3]radialenes has been studied to a limited extent [18–21]. Three coordination modes were observed for hexa(2-pyridyl)[3]radialene with Ag(I): A discrete M 6 L 2 cage, a 1-D coordination polymer composed of M 3 L 2 cages bridged by linear silver atoms, and a second 1-D coordination polymer where the radialene ligand acts as a tetradentate bridge [18–19].…”

“…Three coordination modes were observed for hexa(2-pyridyl)[3]radialene with Ag(I): A discrete M 6 L 2 cage, a 1-D coordination polymer composed of M 3 L 2 cages bridged by linear silver atoms, and a second 1-D coordination polymer where the radialene ligand acts as a tetradentate bridge [18–19]. Hexa(4-pyridyl)[3]radialene also acts as a bridging ligand in a 3-D coordination polymer with AgClO 4 [20], while isomorphous 6,3-connected 2-D coordination polymers were obtained when hexakis(4-cyanophenyl)[3]radialene was reacted with AgPF 6 and AgClO 4 [21]. …”

Pre-organisation or a hydrogen bonding mismatch: silver(I) diamide ligand coordination polymers versus discrete metallo-macrocyclic assemblies

“…20,21,26,[34][35][36][37][38] Such self assembled metallosupramolecular species have been employed as anion sensors. 39 In this latter context, we have directed our attention toward two major types of organic ligand, namely, electron deficient [3]radialene compounds [40][41][42][43][44] and heterocyclic amide ligands, [45][46][47] in an effort to generate simple metallo-supramolecular assemblies and coordination polymers that encapsulate anions. Flexible bis-amide containing ligands (Diagram 1) were chosen to probe the effects of having two different and potential competing, orthogonal, supramolecular synthons in the same component; namely metal donor sites and hydrogen bond donor/acceptor moieties.…”

Ruthenium complexes of hexakis(cyanophenyl)[3]radialenes and their di(cyanophenyl)methane precursors: synthesis, photophysical, and electrochemical properties

“…The coordination chemistry of hexaaryl-and hexa-heteroaryl [3]radialenes has been studied to a limited extent [23][24][25][26][27]. Two isomers (rac and meso) of a dinuclear bis(2,2'-bipyridyl)ruthenium(II) complex incorporating 1 have also been reported [28], although no metal-metal interactions were observed.…”