Periodicity in Structure, Bonding, and Reactivity for p-Block Complexes of a Geometry Constraining Triamide Ligand

Area of Science:

• Main-group chemistry
• Organometallic chemistry
• Ligand design

Background:

• Pincer ligands are key to achieving non-VSEPR geometries in main-group elements.
• Previous studies used diverse ligands, hindering clear structure-reactivity relationships.
• Systematic studies are needed to understand periodic trends.

Purpose of the Study:

• To investigate periodic trends in structure, bonding, and reactivity.
• To correlate geometry (bent vs. planar) with electronic properties and reactivity.
• To establish a benchmark dataset for main-group pincer ligand chemistry.

Main Methods:

• Synthesized and characterized a homologous series of pincer complexes with varying central elements (P, As, Sb, Bi).
• Employed solid-state, solution, and computational methods (including energy decomposition analysis).
• Quantitatively determined thermodynamic parameters for observed dynamic covalent dimerization.

Main Results:

• A trend towards planar geometries was observed down the group (P, As bent; Sb, Bi planar).
• Planar geometries correlated with lower LUMO energies and smaller band gaps.
• Phase-dependent dynamic covalent dimerization was observed for the antimony complex.

Conclusions:

• Systematic variation of the central element in pincer complexes reveals predictable geometric preferences.
• Geometry significantly influences electronic properties and reactivity patterns.
• This work provides a foundational dataset for designing novel main-group compounds with tunable reactivity.