Insights into the decomposition of zirconium acetylacetonate using synchrotron radiation: Routes to the formation of volatile Zr-intermediates

Abstract

The thermal decomposition of Zr(acac)4 is studied in a SiC-microreactor on the micro-second time scale. By utilizing synchrotron radiation and photoelectron photoion coincidence spectroscopy, six important zirconium intermediates, as for instance Zr(C5H7O2)2(C5H6O2), and Zr(C5H6O2)2, are identified in the gas phase for the first time. The adiabatic ionization thresholds of intermediately formed zirconium species are estimated and the main products of their thermal decomposition, acetylacetone, acetylallene and acetone are characterized unambiguously and isomer-selectively. Based on all detected intermediates, we deduce the predominant pyrolysis pathways of the precursor in the temperature range from 400 to 900 K. Our findings are complemented by numerical simulations of the flow field in the microreactor, which show that the choice of dilution gas significantly influences the temperature profile and residence times in the microreactor, such that helium provides a more uniform flow field than argon and should preferentially be used. Graphical abstract Using a soft ionization method coupled to velocity map imaging (VMI), leads to valuable insights in the thermal decomposition of Zr(C5H7O2)4, used in the synthesis of functional nanomaterials and ceramic coatings. Thanks to the use of a microreactor, important gas

Thermal Activation of Zirconium(IV) Acetylacetonate Catalysts to Enhance Polyurethane Synthesis and Reprocessing

“…A peak corresponding to acetone ( m / z = 58) was not observed, suggesting that the acac ligand evaporates without fragmentation and deprotonates the residual Zr complex to form the volatile neutral ligand. This proposed decomposition pathway is consistent with previous studies. − Heating Zr­(acac) 4 at 120 °C resulted in less than 5% mass loss, indicating that this decomposition pathway requires temperatures of at least 140 °C. Increased mass loss that leveled off at 40% occurred when Zr­(acac) 4 was heated to temperatures between 180 and 220 °C (Figure A).…”

Solution-processed zirconium acetylacetonate charge-trap layer for multi-bit nonvolatile thin-film memory transistors

“…Therefore, irrespective of the desired low-temperature processed CTL, the optimized CTL should have good thermal properties, mechanical stability, good scalability, and to withstand the possible harsh processing conditions of semiconductors in multi-layered vertically stacked device structures. Acetylacetonate precursor, a carbon-containing bidentate ligand, is known to be a good precursor for organometallic deposition of a wide range of metals including Zr with notably high stability constant and thermally stable [ 17 , 18 ]. A low-temperature processed zirconium acetylacetonate (ZAA) Zr(C 5 H 7 O 2 ) 4 is promising for high efficient CTMs, which is applicable to a wide variety of substrates and semiconductors owing to its favorable high thermal properties.…”