Enthalpy of sublimation of hydroxyl-containing amino acids: Knudsen’s effusion mass spectrometric study

High-pressure polymorphism inl-threonine between ambient pressure and 22 GPa

“…The use of this method has been validated by comparison of lattice energy of L-threonine with the experimental value, by comparing the total energies of the compressed structures with those obtained by DFT calculations, and finally by comparing individual molecule-molecule energies at ambient pressure and 17.1 GPa with values obtained with symmetry adapted perturbation theory. The experimental enthalpy of sublimation of L-threonine is 161 kJ mol −1 at 298.15 K, 72 but once proton transfer between the ammonium and carboxylate groups during sublimation is taken into account, 73 the energy of sublimation of zwitterionic L-threonine is 270.7 ± 7 kJ mol −1 , which compares with the PIXEL value of 252.0 kJ mol −1 .…”

Molecular Structure, Thermodynamic and Spectral Characteristics of Metal-Free and Nickel Complex of Tetrakis(1,2,5-thiadiazolo)porphyrazine

“…The sublimation of H 2 TTDPz and NiTTDPz has been investigated by Knudsen method using the MI-1201 commercial magnetic sector mass spectrometer adapted to thermodynamic studies and described in detail in [ 43 , 44 ]. The solid samples were sublimated from a stainless steel effusion cell.…”

Sublimation Thermodynamics of 5,10,15,20–Tetraphenyl-21-X, 23-Y-Heteroporphyrins (X=O or S; Y= N or S). The Molecular structure of 5,10,15,20-Tetraphenyl-21-thiaporphyrin

“…Accelerating voltage of 5 kV and the energy of ionizing electrons of 50 eV were applied during the experiments. The temperature of the of the effusion cell was measured by a tungstenrhenium thermocouple W-Re 5/20, calibrated against the melting point of Sn, and the slopes ln(IT) = f(1000/T) against the sublimation enthalpies of benzoic acid and Gly, as described earlier [ 17 ]. The power supplies (ionization and accelerating voltages, emission current, etc.)…”