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Synthesis and characterization of volatile liquid cobalt amidinates
Zhengwen Li1, Don Kuen Lee, Michael Coulter
1Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA.
Dalton Transactions (Cambridge, England : 2003)
|April 30, 2008
Summary
Three new cobalt amidinate compounds were synthesized and found to be volatile and thermally stable. These compounds are excellent precursors for vapor deposition of cobalt-based materials.
Area of Science:
- Inorganic Chemistry
- Materials Science
- Chemical Engineering
Background:
- Volatile metal-organic compounds are crucial for chemical vapor deposition (CVD) processes.
- Cobalt precursors are needed for depositing cobalt metal, nitride, and oxide thin films.
- Existing cobalt precursors may have limitations in volatility, stability, or ease of synthesis.
Purpose of the Study:
- To synthesize and characterize novel volatile cobalt amidinate compounds.
- To evaluate their suitability as precursors for vapor deposition applications.
- To develop an efficient and cost-effective synthetic route.
Main Methods:
- Synthesis of cobalt amidinate complexes: Co(tBuNC(R)NEt)2, where R = Me, Et, n-Bu.
- Characterization techniques: elemental analysis, 1H NMR, X-ray structure analysis.
- Evaluation of physical properties: melting point, vapor pressure, vaporization rate, thermal stability, and chemical reactivity.
Main Results:
- Three new volatile cobalt amidinate compounds were successfully prepared.
- Two compounds are liquids at room temperature, facilitating handling and purification via distillation.
- The compounds exhibit clean evaporation without decomposition and are suitable for vapor deposition.
Conclusions:
- Novel cobalt amidinate compounds offer convenient handling and purification due to their liquid nature and volatility.
- These compounds serve as effective precursors for the vapor deposition of cobalt metal, cobalt nitride, and cobalt oxide.
- A scalable and economical synthetic method enables large-scale production.
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