Thermal Decomposition Mechanism of Bis(dipivaloylmethanato)strontium Compounds Containing Glyme Adducts

Abstract

The mechanisms of the thermal decomposition of Sr͑dpm͒ 2 , Sr͑dpm͒ 2 -triglyme, and Sr͑dpm͒ 2 -tetraglyme, where Sr͑dpm͒ 2 is bis͑dipivaloylmethanato͒strontium, were examined using thermogravimetric analysis, mass spectrometry, and Fourier transform infrared spectroscopy ͑FTIR͒. The chemical bonds in the Sr compounds are sequentially decomposed as the compounds are heated. That is, glyme adducts are decomposed at temperatures below 200°C, and the Sr-O and the C-C(CH 3 ) 3 bonds are dissociated at higher temperatures, whereas the C-O and the C-C bonds remain stable at temperatures up to 400°C. Glyme adducts in the Sr compounds weaken the Sr-O bond between the central Sr atom and the dpm ligand, and, as a result, the Sr-O bond in Sr͑dpm͒ 2 -glymes is dissociated at lower temperatures than the bond in Sr͑dpm͒ 2 . However, Sr͑dpm͒ 2 -glymes are more effectively protected from degradation, thus yielding smaller amounts of residues at elevated temperatures than Sr͑dpm͒ 2 . The FTIR results suggest that a fraction of the dissociated glyme species remains bonded to the Sr compound such that the bonded species suppresses the flexibility of the dpm ligand and consequently, access of other molecules to the central Sr atom. Sr͑dpm͒ 2 -triglyme is stabilized by glyme adducts more effectively than Sr͑dpm͒ 2 -tetraglyme, which is thought to originate from different numbers of oxygen atoms coordinated with the Sr atom between the two compounds.

Glymes as versatile solvents for chemical reactions and processes: from the laboratory to industry

“…Sr(dpm) 2 ] compounds containing glyme adducts [i.e. Sr(dpm) 2 -triglyme and Sr(dpm) 2 -tetraglyme] was examined by Cho et al 110 using thermogravimetric analysis, mass spectrometry, and FT-IR spectroscopy. They observed that glyme adducts are decomposed below 200°C, while the Sr-O and the C-C(CH 3 ) 3 bonds are dissociated at higher temperatures, and the C-O and the C-C bonds are stable up to 400°C.…”

Chemically conformal deposition of SrTiO3 thin films by Atomic Layer Deposition using conventional metal organic precursors and remote-plasma activated H2O

“…Thermal decomposition mechanism of Sr(thd) 2 has been studied by searchers using thermo-gravimetry (TG) analysis or Fourier transformed infra-red spectroscopy (FTIR) [8]- [10] . TG analyses showed a drastic decrease in weight of Sr(thd) 2 precursor at approximately 200 that could be interpreted as suggesting that C-C, C-O and C-H bonds begin to break at this temperature.…”

“…TG analyses showed a drastic decrease in weight of Sr(thd) 2 precursor at approximately 200 that could be interpreted as suggesting that C-C, C-O and C-H bonds begin to break at this temperature. It is believed that those bonds breaking is related to the thermal dissociation of tert-buthyl group from the thd ligand [9]- [10] .…”