Thermal Stability and Decomposition Pathways in Volatile Molybdenum(VI) Bis-imides

Area of Science:

• Materials Science
• Inorganic Chemistry
• Chemical Engineering

Background:

• Molybdenum-containing films are crucial for advanced applications.
• Current volatile precursors for molybdenum film deposition have limitations.

Purpose of the Study:

• To synthesize and characterize novel bis(tert-butylimido)molybdenum(VI) adducts.
• To investigate the volatility, thermal stability, and decomposition of these new compounds.
• To explore structure-property relationships for precursor design in vapor deposition.

Main Methods:

• Synthesis of (tBuN)2MoCl2 adducts with N,N'-chelates.
• Thermogravimetric analysis (TGA) for volatility assessment.
• Differential scanning calorimetry (DSC) for thermal stability.
• Single-crystal X-ray diffraction for structural characterization.

Main Results:

• Identified 1,4-di-tert-butyl-1,3-diazabutadiene adduct (5) as the most volatile precursor.
• Determined 1,10-phenanthroline adduct (4) as the most thermally stable compound.
• Investigated decomposition pathways, including gamma-H activation, for various alkyl-substituted imido groups.
• Reported 19 new molybdenum compound structures.

Conclusions:

• Novel molybdenum adducts offer tunable volatility and stability for vapor deposition.
• Understanding decomposition mechanisms aids in designing improved precursors.
• The reported structures provide fundamental insights into molybdenum chemistry.