Pyrolysis pathways and kinetics of thermal decomposition of diethylzinc and diethyltellurium studied by mass spectrometry
Abstract
The thermal decomposition of diethylzinc (Et2Zn) and diethyltellurium (Et2Te) has been studied both separately and combined using an isothermal reactor attached to a quadrupole mass spectrometer (QMS). Under helium and hydrogen atmospheres the decomposition of Et2Zn leads to ethene, ethane and n-butane; with D2 as a carrier gas C2H5D is produced. Pyrolysis of Et2Te leads to ethane and ethene only. With helium as the carrier gas, the activation energy for the pyrolysis was E ≈ 52 kcal mol–1 for Et2Zn and E ≈ 50 kcal mol–1 for Et2Te, firstorder kinetics being assumed. Under a hydrogen atmosphere, the determination of the activation energy for the pyrolysis of Et2Zn was inaccurate with a first-order reaction rate, and the activation energy for the pyrolysis of Et2Te was reduced to E ≈ 47 kcal mol–1. In the co-pyrolysis, which is close to the conditions of ZnTe growth, the principal trends are enhancement of Et2Te decomposition and an increase of the thermal stability of Et2Zn.