Internal Diene Ligands for Platinum Catalyst Stability
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Solution Overview
Problem
Current platinum catalysts used in hydrosilylation reactions are inefficient due to high costs, substrate loss, and environmental pollution, with a need for improved catalysis that reduces platinum consumption and enhances reaction stability and compatibility.
Innovation Solution
Development of internal dienic ligands and their complexes with periodic Groups IX, X, and Pt Group metals, specifically platinum, for use in hydrosilylation and C—C/C—N/C—O coupling reactions, which form stable, reusable catalysts that reduce platinum usage and improve reaction rates and product quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If common platinum catalysts (Speier's, Karstedt's) are used for hydrosilylation, then catalytic activity is achieved, but platinum consumption is high and catalyst stability is poor
Solution Approach 1:
The patent modifies the ligand structure by using internal dienes with specific electronic and steric properties instead of traditional vinyl or external diene ligands. This changes the electronic parameters of the catalyst complex, improving Pt stability and reducing consumption while maintaining catalytic activity for hydrosilylation reactions
Solution Approach 2:
The invention creates composite catalyst systems by combining platinum with internally unsaturated dienic ligands that contain both carbon-carbon and silicon-oxygen bonds. This composite structure provides enhanced stability and reduced platinum consumption compared to conventional homogeneous Pt catalysts
2Productivity
If higher platinum loadings are used to compensate for active catalyst loss, then catalytic activity is maintained, but cost increases and environmental pollution worsens
Solution Approach 1:
By changing the ligand parameters to internal dienes with optimized electronic properties, the catalyst maintains high activity at lower Pt loadings, thereby reducing environmental pollution associated with excessive platinum use and disposal
Solution Approach 2:
The patent replaces the disposable nature of conventional Pt catalysts that require high loadings and frequent replacement with a more durable internally coordinated catalyst that maintains activity over longer periods at lower concentrations, reducing waste
3Productivity
If traditional vinylsiloxane ligands are used in Pt catalysts, then catalysis proceeds, but substrate loss occurs due to side reactions
Solution Approach 1:
The patent changes the ligand from vinyl or external diene to internal diene structure, which modifies the steric and electronic parameters around the platinum center. This reduces unwanted side reactions with substrates while maintaining the desired hydrosilylation pathway, thereby reducing substrate loss
4Productivity
If conventional Pt catalysts are used for cross-linking/cure applications, then curing is achieved, but catalyst recovery and recycling are not feasible
Solution Approach 1:
By using internal diene ligands that form stable but dynamic coordination bonds with platinum, the catalyst maintains effectiveness during cross-linking while enabling potential recovery through ligand exchange or decomposition methods, improving recyclability compared to conventional catalysts
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The use of internal dienic ligands and their complexes leads to reduced platinum consumption, enhanced reaction stability, improved compatibility, and increased efficiency in hydrosilylation processes, resulting in faster cure times, lower by-product formation, and reduced environmental impact.
Implementation Method 1
internal dienic ligands and their complexes with periodic Groups IX, X, and Pt Group metals
Implementation Method 2
platinum and the preferred catalyzed reaction is hydrosilylation
Data Source
AI summary
Internal dienes (including supported versions) and their Periodic Groups IX, X and Pt Group Metal Complexes as catalysts for hydrosilylation/coupling reactions. A process for the hydrosilylation of an unsaturated compound comprising reacting (a) a silyl or siloxy hydride with (b) an unsaturated compound in the presence of (c) one or more platinum complex containing said internal dienic ligand or (d) a platinum compound and one or more said internal dienic ligand additive. For Ru, Os, Co, Rh, Ir, Ni, or Pd, catalyzed processes such as C—C/C—N or C—O coupling comprising reacting (a) an aromatic halide/vinyl halide/an aromatic triflate with (b) a primary/secondary amine/amide, an alcohol/aryl boronic acid/aryl boronate/vinyl halide or an activated olefin in the presence of (c) a Group IX or X or Pt Group metal complex containing said dienic ligand(s) or (d) a suitable compound of these metals and of one or more said internal dienic ligand additive.