High pressure crystallography

High pressure crystallography is a branch of crystallography that investigates crystalline materials at pressure conditions different from ambient. By applying pressure to a crystal, one enhances the internal energy of the system, enabling phase transformation to polymorphs which are less stable at ambient pressure. The changes cmay involve only interolecular interactions (at low-medium pressure, at ca. 0-10 GPa) or intramolecular ones as well (at higher pressure well above 10 GPa). Structural changes imply also different electroni, optic or magnetic properties.
Our studies focus on molecular crystals that can be transformed by high pressure, in particular fostering the reactvity of molecules.

Principal investigator: Prof. Piero Macchi
Main collaborators: Dr. Nicola Casati (Paul Scherrer Institute, Switzerland); Dr. Tomasz Poreba (ESRF, France); Dr. Fabio Montisci (IMT, Italy); Dr. Arianna Lanza (Istituto italiano di Tecnologia, Pisa, Italy); Prof. W. Scherer (Univ. Augsburg, Germany)

Recent research work

Scatena, R.; Montisci, F.; Lanza, A.; Casati, N.P.M.; Macchi, P. (*), Inorg. Chem., 2020, 59, 10091-10098. (pdf)
Magnetic Network on Demand: Pressure Tunes Square Lattice Coordination Polymers Based on {[Cu(pyrazine)2]2+}n

Poreba, T.; Macchi, P.; Casati, N.P.M. Cryst. Growth & Design , 2020, 20, 4375-4386. (pdf)
Structural Variety of Alkali Hydrogen Maleates at High Pressure

Racioppi, S.; Andrzejewski, M; Colombo, V.; Sironi, A.; Macchi, P.(*) Inorg. Chem. , 2020, 59, 2223–2227. (pdf)
Different Metallophilic Attitudes Revealed by Compression

Poreba, T.; Ernst, M.; Zimmer, D.; Macchi, P.(*); Casati, N. Angew. Chem. Int. Ed. Engl., 2019, 131, 6697-6701.(pdf)
Pressure- Induced Polyme rization and Electrical Condu ctivity of a Polyiodide

Wehinger, B.; Fiolka, C.; Lanza, A.; Scatena, R.; Kubus, M.; Grockowiak, A.; Coniglio, W. A.; Graf, D.; Skoulatos, M.; Chen, J. -H.; Gukelberger, J.; Casati, N.; Zaharko, O.; Macchi, P.; Krämer, K. W.; Tozer, S.; Mudry, C.; Normand, B.; Rüegg, C. Phys. Rev. Lett., 2018, 121, 117201 (pdf)
Giant pressure dependence and dimensionality switching in a metal-organic quantum antiferromagnet

Casati, N.; Genoni, A.; Meyer, B.; Krawczuk, A.; Macchi, P.(*) Acta Cryst. 2017, B73, 584–597. (pdf)
Exploring charge density analysis in crystals at high pressure: data collection, data analysis and advanced modelling

Casati, N.; Kleppe, A.; Jephcoat, A.; Macchi, P.(*) Nature Comm. 2016, 7, 10901(pdf)
Putting pressure on aromaticity along with in situ experimental electron density of a molecular crystal

Scherer, W.; Dunbar, A. C.; Barquera-Lozada, J. E.; Schmitz, D.; Eickerling, G.; Kratzert, D.; Stalke, D.; Lanza, A.; Macchi, P.(*); Casati, N.;Ebad-Allah, J.; Kuntscher, C. Angew. Chem. 2015, 54, 2505 –2509 (pdf)
Anagostic Interactions under Pressure: Attractive or Repulsive?