The complexes of bis[N-alkyl-2-hydroxonapthaldimine]nickel(II) (N-alkyl = methyl, ethyl, propyl, butyl or pentyl) were synthesized and their volatilization in N2 atmosphere was demonstrated by the TG-based transpirati...The complexes of bis[N-alkyl-2-hydroxonapthaldimine]nickel(II) (N-alkyl = methyl, ethyl, propyl, butyl or pentyl) were synthesized and their volatilization in N2 atmosphere was demonstrated by the TG-based transpiration technique. The equilibrium vapor pressure of the complexes over a temperature span of 470 - 590 K was determined by adapting a horizontal dual arm single furnace thermoanalyser as a transpiration apparatus. It yielded as 153.1 (±1.9), 122.9 (±0.3), 147.6 (±10.7), 151.8 (±10.9) and 114.7 (±5.3) k·Jmol–1 respectively. The entropies of vaporization for these complexes as calculated from the intercept of the linear fit expressions were found to be 319.7 (±3.9), 229.9 (±5.8), 317.8 (±17.2), 319.7 (±19.1) and 254.6 (±9.6) Jmo–1·K–1 respectively. The non-isothermal vaporization activation energy was determined from Arrhenius and Coats-Redfern methods.展开更多
The bis(N-ethyl-5-methylsalicylaldimine)nickel(II) [Ni(5-me-saletN)2] complex was synthesized and characterized by elemental analyses, FT-IR, TG-DTA, mass spectrometry and vapour pressure measurement studies. The TG c...The bis(N-ethyl-5-methylsalicylaldimine)nickel(II) [Ni(5-me-saletN)2] complex was synthesized and characterized by elemental analyses, FT-IR, TG-DTA, mass spectrometry and vapour pressure measurement studies. The TG curve of the complex showed a single-step weight loss commencing from 490 K to nil residue at 600 K, without competing fragmentation step. The non-isothermal vaporization activation energy value determined by Coats-Redfern method yielded the value of 93.5 ± 7 kJmol–1. The dynamic TG run proved the complex to be completely volatile. And the equilibrium vapour pressure of the complex over the temperature range of 421 - 524 K, determined by the TG-based transpiration technique yielded the value of 94.2 ± 1.2 kJmol–1 for its standard enthalpy of vaporization . The entropy of vaporization was calculated from the intercept and found to be 249.4 ± 2.6 Jmol–1•K–1.展开更多
文摘The complexes of bis[N-alkyl-2-hydroxonapthaldimine]nickel(II) (N-alkyl = methyl, ethyl, propyl, butyl or pentyl) were synthesized and their volatilization in N2 atmosphere was demonstrated by the TG-based transpiration technique. The equilibrium vapor pressure of the complexes over a temperature span of 470 - 590 K was determined by adapting a horizontal dual arm single furnace thermoanalyser as a transpiration apparatus. It yielded as 153.1 (±1.9), 122.9 (±0.3), 147.6 (±10.7), 151.8 (±10.9) and 114.7 (±5.3) k·Jmol–1 respectively. The entropies of vaporization for these complexes as calculated from the intercept of the linear fit expressions were found to be 319.7 (±3.9), 229.9 (±5.8), 317.8 (±17.2), 319.7 (±19.1) and 254.6 (±9.6) Jmo–1·K–1 respectively. The non-isothermal vaporization activation energy was determined from Arrhenius and Coats-Redfern methods.
文摘The bis(N-ethyl-5-methylsalicylaldimine)nickel(II) [Ni(5-me-saletN)2] complex was synthesized and characterized by elemental analyses, FT-IR, TG-DTA, mass spectrometry and vapour pressure measurement studies. The TG curve of the complex showed a single-step weight loss commencing from 490 K to nil residue at 600 K, without competing fragmentation step. The non-isothermal vaporization activation energy value determined by Coats-Redfern method yielded the value of 93.5 ± 7 kJmol–1. The dynamic TG run proved the complex to be completely volatile. And the equilibrium vapour pressure of the complex over the temperature range of 421 - 524 K, determined by the TG-based transpiration technique yielded the value of 94.2 ± 1.2 kJmol–1 for its standard enthalpy of vaporization . The entropy of vaporization was calculated from the intercept and found to be 249.4 ± 2.6 Jmol–1•K–1.
