Ruthenium agostic (phosphinoaryl)borane complexes: multinuclear solid-state and solution NMR, X-ray, and DFT studies

Area of Science:

• Organometallic Chemistry
• Coordination Chemistry
• Boron Chemistry

Background:

• The development of novel ligands is crucial for advancing catalytic processes.
• Ruthenium complexes are widely studied for their catalytic potential.
• Bifunctional ligands offer unique coordination modes and reactivity.

Purpose of the Study:

• To investigate the reactivity of a (phosphinoaryl)(amino)borane ligand with a bis(dihydrogen)ruthenium complex.
• To characterize the resulting complexes using various spectroscopic and crystallographic methods.
• To understand the coordination behavior and electronic properties of the ligand in the ruthenium complex.

Main Methods:

• Density Functional Theory (DFT) calculations
• X-ray diffraction analysis
• Multinuclear Nuclear Magnetic Resonance (NMR) spectroscopy, including solid-state NMR

Main Results:

• Synthesis and characterization of a novel ruthenium complex featuring the bifunctional ligand.
• Observation of ligand dissociation and formation of an unsaturated 16-electron ruthenium complex in solution.
• Identification of a Ru-H-B interaction, indicative of an agostic interaction.

Conclusions:

• The (phosphinoaryl)(amino)borane ligand acts bifunctionally through its phosphine and amino-borane moieties.
• The study demonstrates the formation of an agostic interaction in the ruthenium complex.
• The findings contribute to the understanding of ligand design and reactivity in organometallic chemistry.