Abstracts » Chemicals, plastics and rubber industries

Toward the computational design of diastereomeric resolving agents: An experimental and computational study of 1-phenylethylammonium-2-phenylacetate derivatives

Article Abstract:

Low-temperature single crystal or powder X-ray diffraction is used to characterize the crystal structures, including two new polymorphs, of three diastereomerically related salt pairs formed by 1-phenylethylammonium with 2-phenylpropanoate, 2-phenylbutyrate and mandelate ions. The findings demonstrate that the stability difference of the diastereomeric salt pairs of three 1-phenylethylammonium-2-phenylacetate derivatives is related to their resolution efficiency and varies considerably, despite the similarity in their molecular structure and hydrogen-bonding motifs.

Observations, Molecular structure, X-rays, X-ray diffraction, Hydrogen bonding, Hydrogen bonds, Phenethylamines, Chemical properties

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Challenges of crystal structure prediction of diastereomeric salt pairs

Article Abstract:

The computational prediction of the crystal structures and resolution efficiency for diastereomeric salt pairs was studied by considering the polymorphic system of the diasteromeric salt pair (R)-1-phenylethylammonium (R/S)-2-phenylpropanoate. The sensitivity of the computed lattice energies to the fine details of the ion conformations overtaxed computational models and presented the design of diasteromeric resolution processes by computational chemistry a challenging problem.

Crystals, Crystal structure, Thermal properties, Computational chemistry, Diastereomers

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Atomistic calculations of phonon frequencies and thermodynamic quantities for crystals of rigid organic molecules

Article Abstract:

The forces between molecules determine phonon frequencies and the corresponding motions, and the choice of intermolecular potential is a key factor in the accuracy of calculations. Rigid body, k = 0 phonon frequencies of five molecular organic crystals is calculated by standard lattice dynamical methods.

Molecules, Thermodynamics, Phonons

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