Programmable Synthesis of Silver Wheels

The synthesis of sandwich-shaped multinuclear silver complexes with planar penta- and tetranuclear wheel-shaped silver units and a central anion, [Ag_n(2-HPB)₂(A^-)](OTf^-)_n-1, nAg^A, n = 4 or 5 and A^- = OH^- or F^- or Cl^-, is reported, along with complete spectroscopic and structural characterization. An NMR mechanistic study reveals that silver complexes were formed in the following order: 2Ag → 3Ag^H₂O → 5Ag^OH → 4Ag^OH. The central hydroxides in 4Ag^OH and 5Ag^OH exhibit exotic physical properties due to the confined environment inside the complex. The size of these silver wheels can be tuned by changing the central anion or extracting/adding one silver atom. This study provides the facile way to synthesize discrete wheel-shaped multinuclear silver complexes and provides valuable insights into the dynamics of the self-assembly process.

Self-Assembly of Multinuclear Sandwich Silver(I) Complexes by Cooperation of Hexakis(azaheteroaryl)benzene Ligands, Argentophilic Interactions, and Fluoride Inclusion

Self-assembly of AgOTf and AgF with the hexatopic ligands hexakis(pyridin-2-yl)benzene (2) and 2,4,6-tris(pyridin-2-yl)-1,3,5-tris(quinolin-2-yl)benzene (3) affords the discrete sandwich-shaped complexes [Ag₄F(2)₂](OTf)₃, [Ag₄F(3)₂](OTf)₃, and [Ag₅F(2)₂](OTf)₄. The solid-state structures of the complexes were characterized by single-crystal X-ray diffraction analysis, which revealed that the fluoride anion is coordinated in the center of the Ag₄-square or Ag₅-pentagon units which are positioned between two molecules of the hexakis(azaheteroaryl)benzene. The generation of complexes is dictated by a unique cooperation of ligand coordination, argentophilicity, and fluoride anion inclusion. All three complexes adopt highly symmetrical structures in solution, as evidenced by appearance of one set of proton resonances for the two ligands arranged face to face.

Multinuclear sandwich-shaped silver(I) complexes are readily assembled by a unique cooperation of nitrogen-coordinating hexaheteroarylbenzene ligands, silver atoms, and fluoride anion.

Metallosupramolecular Compounds Based on Copper(II/I) Chloride and Two Bis-Tetrazole Organosulfur Ligands

The present work assesses the ability of two flexible bis-tetrazole organosulfur ligands to build up different metallosupramolecular compounds based on the analysis of the different supramolecular interactions. The reaction of copper(II) chloride dihydrate with the N,N’-donor dithioether ligands bis(1-methyl-1H-tetrazole-5-ylthio)methane (BMTTM) and 1,2-bis(1-methyl-1H-tetrazole-5-ylthio)ethane (BMTTE) was investigated using different synthetic methods. Four compounds have been obtained as single crystals: two pseudopolymorphic 1D Cu(II) coordination polymers with the ligand BMTTM, a 2D Cu(II) coordination polymer and a discrete Cu(I) tetramer with the BMTTE ligand. The effects of the weak interactions on the crystal packing and the Hirshfeld surfaces of the structures were analyzed to clarify the nature of the intermolecular interactions.

Fluxional motion in a dinuclear copper(i) complex with a propeller-type ligand: metal hopping on both sides

Fluxional motion of a dicopper(i) complex of hexa(2-pyridyl)benzene that accompanies metal hopping processes and ring rotation was studied.

Coordination preference of hexa(2-pyridyl)benzene with copper(ii) directed by hydrogen bonding

Coordination modes of hexa(2-pyridyl)benzene ligand with copper(ii) ions were controlled by different solvents mainly due to hydrogen bonding.