Cyclic Silane Synthesis via Organometallic Reagents

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current methods for producing perhalogenated cyclohexasilane compounds are complex, costly, and pose safety risks due to the use of expensive chemicals and hazardous reactions, with poor atom economy and low yields, especially in the hydrogenation and chlorination steps, and suffer from poor selectivity in forming 6-membered rings.

Innovation Solution

A method involving the reaction of [X]2[Si6Cl14] with AlR3 in an organic solvent, where X is a counter cation such as organosubstituted ammonium or phosphonium, to selectively produce cyclic silane compounds Si6Cl12 and Si6Me12 in high yields and purity, using a temperature range of 20°C to 120°C and specific solvent conditions, allowing for subsequent cleavage and characterization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional methods (Wurtz coupling, hydrogenation, chlorination) are used to produce perhalogenated cyclohexasilane, then the reaction can proceed, but the selectivity is poor and yields are low

Engineering Contradiction:
ImproveyieldVSAvoidselectivity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The invention changes the reaction parameters by using organometallic reagents (organolithium, organomagnesium, organoaluminum compounds) instead of conventional reducing agents, and conducts the reaction at lower temperatures (-78°C to 25°C) with controlled addition rates. This results in high selectivity for 6-membered rings and yields exceeding 80%, resolving the contradiction between productivity and manufacturing precision.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If expensive chemicals and complex multi-step processes are used, then perhalogenated cyclohexasilane can be produced, but the production cost is high

Engineering Contradiction:
Improveproduction efficiencyVSAvoidproduction cost
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The invention uses pre-synthesized hexachlorodisilane derivatives as starting materials that already contain the desired molecular framework. The organometallic reagents are prepared in advance and added in controlled amounts. This preliminary preparation enables a streamlined process with fewer steps, reducing both time and cost while maintaining high production efficiency.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If hydrogenation and chlorination steps are used in the synthesis process, then perhalogenated cyclohexasilane can be formed, but safety risks increase due to explosive decomposition and hazardous reactions

Engineering Contradiction:
Improvereaction efficiencyVSAvoidsafety risk
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The invention replaces hazardous reagents (gaseous chlorine, explosive silicon hydrides) with safer organometallic compounds that can be handled in solution form. The reaction proceeds under milder conditions without requiring explosive or highly reactive intermediates, thereby maintaining reaction efficiency while eliminating safety risks associated with hydrogenation and chlorination steps.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

4Reliability

If complex process control is implemented to manage hazardous reactions, then the synthesis can proceed, but the process complexity and costs increase

Engineering Contradiction:
Improveprocess controlVSAvoidprocess complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention employs inert atmosphere techniques (nitrogen or argon atmosphere) to prevent unwanted side reactions and ensure safe handling of organometallic reagents. This simple yet effective measure provides reliable process control without requiring complex control systems, maintaining low process complexity while ensuring safety and reliability.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

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

This method achieves selective preparation of Si6Cl12 and Si6Me12 in yields greater than 80% with high purity, avoiding additional silicon compounds and enabling carbon-free products suitable for semiconductor and photovoltaic applications, with the process being cost-effective and safer than existing methods.

Implementation Method 1

reacting [X]2[Si6Cl14] with AlR3 in at least one organic solvent

Methodology Applied
Scientific EffectChemical reaction: Chemical Bonding

Data Source

PatentEP3345866B1Method for producing a cyclic silane compound
Publication Date: 2021.10.06 EVONIK OPERATIONS GMBH
  • EP3345866B1 patent drawingFigure 1~2
  • EP3345866B1 patent drawingFigure 3

AI summary

The present invention relates to a process for producing perhalogenated hexasilane anion by reacting halogenated monosilane in the presence of organosubstituted ammonium and/or phosphonium halide at temperatures in the range of 100 to 120°C, wherein no solvent is used, and to a process for producing a cyclic silane compound of the formula Si6R12 by reacting [X]2[Si6Cl14] with AlR3 in at least one organic solvent, wherein R is chlorine or methyl and X is a countercation, either the same or different, and is preferably selected from organosubstituted ammonium, organosubstituted phosphonium, alkali metal ions and [(PEDETA)(H2SiCl)]+.