Substituent Effects on the Supramolecular Aggregation of Ag^I-Pyrazolato Trimers

Abstract

The interplay of argentophilic and dipolar (πacid•••base) interactions, on one hand, and the presence or absence of interstitial solvent molecules, on the other, determines the supramolecular organization of trinuclear silver-pyrazolato complexes in the solid state. The crystal structures of one gold and six silver metallacyclic complexes of the type [M I (μ-pz*)] 3 , where pz* are the substituted pyrazolato anions 3,5-Ph 2 -pz, 3-Me-5-Ph-pz, 4-Br-3,5-Ph 2 -pz, 4-Br-3-t Bu-pz and 3-(o-Cl-C 6 H 4 )-pz and M = Ag and Au, are discussed in the context of their supramolecular organization. Two silver complexes, for which the π-acid character of their Ag 3 -faces is maximized by their peripheral electron-withdrawing substituents, show crystal packing dominated by short Ag 3 •••Br contacts, the first structural manifestation of supramolecular structure via dipolar interactions involving the tunable π-acidity of the Ag 3 -face.

Synthesis, Characterization and Biological Evaluation of Two Silver(I) trans‐Cinnamate Complexes as Urease Inhibitors

“…This may result from the existence of weak Ag1···O2 (2.690(4) Å) and Ag1···Ag1 i (3.2184(11) Å) interactions. The Ag···Ag distance is shorter than the sum of their van der Waals radii (3.44 Å), which is similar to those observed in analogous silver(I) complexes 23,24. This indicates the existence of significant argentophilic interactions.…”

Argentophilic Interactions

“…[342] The various stacking modes of these compounds may lead to only a single intermolecular Ag-Ag contact, [342] but two or three contacts are also common. [343][344][345] With very bulky substituents, the organization of the crystals is determined by other contacts where available, mainly between halogen atoms. [346] The arrangements are influenced not only by the substituent pattern of the individual components, but also by the presence of solvate molecules, [347] predominantly aromatic hydrocarbons.…”

From Metal‐Metal Bonding to Supra‐Metal‐Metal Bonding Directed Self‐Assembly: Supramolecular Architectures of Group 10 and 11 Metals with Ligands from Mono‐ to Poly‐Pyrazoles

“…With different substituent of pyrazolate ligands, different dimer‐of‐trimers structures were obtained by Raptis et al. The distances between the interacted intermolecular Ag⋅⋅⋅Ag varied from 3.142(3) Å to 3.419 Å due to the different substituent and the inclusion of an interstitial solvent molecule in the lattice . In 1990, Fujisawa's group discovered another trimer companied with tetramer was characterized to verify the influence by the steric hindrance exerted by the substituent groups of the pyrazolyl rings .…”