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Krystalografia wysokich ciśnień, czyli jak zobaczyć strukturę materii…głębiej

Olejniczak A., Dziubek K., Paliwoda D., Zieliński W., Podsiadło M., Katrusiak A.

Wiadomości Chemiczne

2014

[Z] 68, 5-6

487--505

During recent decades the number of high-pressure crystallographic studies has rapidly increased. This has been possible owing to the diamond-anvil cell, a small, relatively cheap and save apparatus breaking all records of static pressure. The diamond-anvil cell is suitable for diffraction structural studies, optical and IR spectroscopy and many other types of physical measurements; it can be also applied as a microscopic chemical reaction chamber. High pressure is now often used for synthesizing super-hard materials, new polymorphs and solvates with unique properties required in high-tech applications as well as in food processing and pharmaceutical industry.

The Role of Hydrogen Bonds in the Pressure-Induced structural Distortion of 4-Hydroxyacetanilide Crystals

Boldyreva E., Shakhtshneider T. P., Ahsbabs H., Uchtmann H., Burgina E. B., Baltakhinov V. P.

Polish Journal of Chemistry

2002

Vol. 76 / nr 9

1333-1346

Results of X-ray diffraction and IR-specroscopy studies of the role of hydrogen bonds in the structural distortion of the monoclinic and the orthorhombic polymorphs of paracetamol induced by hydrostatic pressure (up to 4-5 GPa) are analyzed. Two groups of phenomena were studied: (i) the anisotropic structural distortion of the same polymorph, (ii) transitions between the polymorphs induced by pressure. The bulk compressibilities of the two polymorphs are practically equal. The anisotropy of pressure-induced structural distortion is qualitatively different. Lattice expansion in particular crystallographic directions was observed for the monoclinic polymorph. With increasing pressure the intermolecular NH...O and OH...O hydrogen bonds contracted and the intramolecular angles between the planes of the phenyl ring and the acetamide group decreased. Pressure- induced transitions between the polymorphs were poorly reproducible and limited by nucleation of the new polymorph.