https://nova.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:25635 10K_prot) of selected series of primary, secondary and tertiary alkanolamines/amines over the temperature range 288–318 K are reported. Selected series studied involve primary, secondary and tertiary mono-, di- and tri-alkanolamines, secondary amines including heterocyclic species, and both –CH₂OH and –CH₂CH₂OH substituted piperidines. van’t Hoff analyses have resulted in the standard molar enthalpies, ΔH_m^o, and molar entropies, ΔS_m^o, of protonation. Trends in ΔH_m^o are correlated with systematic changes in composition and structure of the selected series of amines/alkanolamines, while ΔH_m^o–ΔS_m^o plots generated linear correlations for the mono-, di-, and tri-alkanolamines, the –CH₂OH and –CH₂CH₂OH substituted piperidines, and the alkylamines. These relationships provide a guide to the selection of an amine(s) solvent for CO₂ capture, based on a greater difference in log₁₀K_prot between the absorber and stripper temperatures.]]> Sat 24 Mar 2018 07:28:09 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:25642 o_m, and entropies, ΔS^o_m of carbamate formation. A ΔH^o_m - ΔS^o_m plot generates a linear correlation for carbamate formation (providing a mean standard molar free energy, ΔG^o_m for carbamate formation of about -7kJ · mol^-1), and this relationship helps provide a guide to the selection of an amine(s) solvent for CO₂ capture, in terms of enthalpy considerations. A linear ΔH^o_m - ΔS^o_m plot also occurs for carbamate protonation. The formation of the carbamates has been correlated with systematic changes in composition and structure, and steric effects have been identified by comparing molecular geometries obtained using density functional B3LYP/6-311++G(d,p) calculations. Trends in steric effects have been identified in the series of compounds monoethanolamine (MEA), 1-amino-2-propanol, 2-amino-1-propanol (AP) and 2-amino-2-methyl-1-propanol (AMP). In the case of 2-piperidinemethanol, 2-piperidineethanol and 3-piperidinemethanol, strong intramolecular hydrogen bonding is shown to be the likely cause for lack of carbamate formation, and in the ring systems of pyrrolidine, morpholine, piperidine and thiomorpho- line trends in carbamate formation (as given by K₉) have been correlated with the internal ring angle at the amine nitrogen, as well as the planarity of the environment around the nitrogen atom.]]> Sat 24 Mar 2018 07:28:08 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:23193 Sat 24 Mar 2018 07:10:26 AEDT ]]>