Multi-nuclear silver(I) and copper(I) complexes: a novel bonding mode for bispyridylpyrrolides

Area of Science:

• Coordination Chemistry
• Organometallic Chemistry
• Supramolecular Chemistry

Background:

• The synthesis of novel metal complexes with tailored ligands is crucial for developing new materials and catalysts.
• Understanding the coordination behavior of polydentate ligands with different metal ions provides insights into structure-property relationships.
• Exploring argentophilic interactions and non-covalent bonding in metal complexes is key to designing advanced supramolecular architectures.

Purpose of the Study:

• To synthesize and characterize novel silver and copper complexes using the 2,5-bis(2 eal'-pyridyl)pyrrole (HPDPH) ligand.
• To investigate the structural diversity and coordination modes of HPDPH with different metal centers (Ag, Cu, Na).
• To examine the influence of ligand structure and metal choice on the resulting complex architectures and intermolecular interactions.

Main Methods:

• Synthesis of metal complexes via reactions of deprotonated HPDPH with silver triflate (AgOTf), copper(I) chloride (CuCl), and other reagents.
• Characterization of the synthesized complexes using techniques such as X-ray crystallography to determine their structures.
• Analysis of structural features including metal-metal distances, ligand conformations, and non-covalent interactions (argentophilic, pi-stacking).

Main Results:

• Formation of a triangular Ag3 complex [(PDPH)Ag]3 (1) with short Ag-Ag distances (2.902 Å).
• Synthesis of linear Ag3 complex [Ag{(PDPH)Ag(PPh3)}2](OTf) (2·OTf) and a di-nuclear complex Li2[(PDPH)Ag2{P(O)(OEt)2}2](OTf) (Li2·3·OTf).
• Preparation of a heterobimetallic copper-sodium complex [Cu(PDPH)2Na(thf)2] (4) and a di-nuclear silver complex with a brominated ligand [(HPDPBr)Ag]2(OTf)2 (5·(OTf)2).

Conclusions:

• The 2,5-bis(2 eal'-pyridyl)pyrrole ligand exhibits versatile coordination behavior, leading to diverse multinuclear silver and copper complexes.
• The nonplanar nature of the HPDPH ligand and observed argentophilic interactions influence the self-assembly and structural characteristics of the complexes.
• The study demonstrates the potential of HPDPH as a building block for constructing complex metal architectures with intriguing structural motifs.