Redetermination of crystal structure of Ag(II)SO4 and its high-pressure behavior up to 30GPa

Mariana Derzsi, Armand Budzianowski, Viktor V. Struzhkin, Przemysław J. Malinowski, Piotr J. Leszczyński, Zoran Mazejd and Wojciech Grochala

CrystEngComm, 2013,15, 192-198 DOI: 10.1039/C2CE26282G

Ag(II)SO4 up to 30GPa

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Polymorphism of Fluoroargentates(II): Facile Collapse of a Layered Network of α-K2AgF4 Due to the Insufficient Size of the Potassium Cation

Dominik Kurzydłowski, Marianna Derzsi, Armand Budzianowski, Zvonko Jagličić, Wiktor Koźmiński, Zoran Mazej, Wojciech Grochala

European Journal of Inorganic Chemistry
Volume 2010, Issue 19, pages 2919–2925, July 2010
DOI: 10.1002/ejic.201000124

Dediacted to the memory of Neil Bartlett


We report the crystal structure and magnetic properties of a novel β polymorph of K2AgF4. β-K2AgF4 is paramagnetic above 20 K and exhibits a low Curie temperature (θ < 5 K). Solid state DFT (GGA and GGA+U) calculations were performed to analyze the electronic and magnetic structure of β-K2AgF4 at 0 K/0 GPa, reproducing correctly the ferromagnetic (FM) semiconductor ground state with the band gap at the Fermi level of approximately 1.65eV. Furthermore, we show that the novel β form is thermodynamically favoured over the previously reported two-dimensional α form and can be formed either by slow spontaneous exothermic α to β phase transition occurring on heating or direct synthesis from KF and AgF2 at 300°C. The relative stability of the α and β phases is rationalized in terms of the size of the M+cation in the M2M′F4 series (M = Na, K, Cs, M′ = Cu, Ag) and the mismatch between [MF] and [M′F4/2] sublattices in the layered perovskite α form.


Coupling of the lactone-ring conformation with crystal symmetry in 6-hydroxy-4,4,5,7,8-pentamethyl-3,4- dihydrocoumarin

Armand Budzianowski and Andrzej Katrusiak

Acta Crystallographica Section B
Structural Science
Volume 58, Part 1 (February 2002)
Acta Cryst. (2002). B58, 125-133 [ doi:10.1107/S0108768101017955 ]
Authorised by IUCr electronic reprint of the article
Revised pages 131 and 132

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Structural polymorphism of pyrazinium hydrogen sulfate: extending chemistry of the pyrazinium salts with small anions

Armand Budzianowski, Mariana Derzsi, Piotr J. Leszczynski, Michał K. Cyrański and Wojciech Grochala

Acta Crystallographica Section B
Structural Science
Volume 66, Part 4 (August 2010)
Acta Cryst. (2010). B66, 451-457 [doi:10.1107/S0108768110019580]
Authorised by IUCr electronic reprint of the article

This work is dedicated to Professor Andrzej Katrusiak to celebrate 30 years of his involvement in research, and in recognition of his contributions to the field of hydrogen-bonded systems (Katrusiak, 1992, 1993).


Two polymorphs ([alpha][beta]) of pyrazinium hydrogen sulfate (pyzH+HSO_4^-, abbreviated as PHS) with distinctly different hydrogen-bond types and topologies but close electronic energies have been synthesized and characterized for the first time. The [alpha]-polymorph (P212121) forms distinct blocks in which the pyzH+ and HSO_4^- ions are interconnected through a network of NH...O and OH...O hydrogen bonds. The  [beta]-form  (P\bar 1) consists of infinite chains of alternating pyzH+ and HSO_4^- ions connected by NH...O and OH...N hydrogen bonds. Density functional theory (DFT) calculations indicate the possible existence of a hypothetical polar P1 form of the [beta]-polymorph with an unusually high dipole moment.


Competing hydrogen-bonding patterns and phase transitions of 1,2-diaminoethane at varied temperature and pressure

 Armand Budzianowski Anna Olejniczak and Andrzej Katrusiak

Acta Crystallographica Section B
Structural Science
Volume 62, Part 6 (December 2006)
Acta Cryst. (2006). B62, 1078-1089 [doi:10.1107/S010876810602982X]


1,2-Diaminoethane has been in-situ pressure- and temperature-frozen; apart from two known low-temperature phases, I[alpha] and II, three new phases, I[beta], I[gamma] and III, have been observed and their structures determined by X-ray diffraction. The measurements at 0.1MPa were carried out at 274, 243 and 224K, and 296K measurements were made at 0.15GPa (phase I[alpha]), at 0.3 and 1.1GPa (phase I[beta]), at 1.5GPa (phase I[gamma]), and at 0.2, 0.3 and 0.5 GPa (phase III). All these phases are monoclinic, space group P21/c, but the unit-cell dimension of phases I[alpha] and III are very different at 296 K: aI[alpha]=5.078(5), bI[alpha]=7.204(8), cI[alpha]=5.528(20)Å, [beta]I[alpha]=115.2(2)° at 0.15GPa, and aIII=5.10(3), bIII=5.212 (2), cIII=7.262 (12)Å, [beta]III = 111.6(4)° at 0.2GPa, respectively; in both phases Z=2. An ambient-pressure low-temperature phase II has been observed below 189K. Discontinuities in the unit-cell dimensions and in the N...N distance mark the isostructural transition between phases I[alpha] and I[beta] at 0.2GPa, which can be attributed to a damping process of the NH2 group rotations. In phase I[gamma] the unit-cell parameter a doubles and Z increases to 4. The molecule has inversion symmetry in all the structures determined. 1,2-Diaminoethane can be considered as a simple structural ice analogue, but with NH...N hydrogen bonds and with the H-atom donors (four in one molecule) in excess over H-atom acceptors (two per molecule). Thus, the transformations of 1,2-diaminoethane phases involving the conformational dynamics affect the hydrogen-bonding geometry and molecular association in the crystal. The 1,2-diaminoethane:1,2-dihydroxyethane mixture has been separated by pressure-freezing, and a solid 1,2-diaminoethane crystal in liquid 1,2-dihyroxyethane has been obtained.


High-pressure crystal phase of 1,2-ethylenediamine

Armand Budzianowski, Anna Olejniczak and Andrzej Katrusiak

Acta Crystallographica Section A
Foundations of Crystallography
Volume 61, (August 2005)
Acta Cryst. (2005). A61, c463


New Polar Phases of 1,4-Diazabicyclo[2.2.2]octane Perchlorate, An NH+···N Hydrogen-Bonded Ferroelectric

Anna Olejniczak, Michalina Anioła, Marek Szafrański, Armand Budzianowski and Andrzej Katrusiak

Cryst. Growth Des., 2013, 13 (7), pp 2872–2879 DOI: 10.1021/cg400276c


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High-Pressure Crystallographic Experiments with a CCD-Detector

Armand Budzianowski, Andrzej Katrusiak

High-Pressure Crystallography NATO Science Series Volume 140, 2004, pp 101-112
Proceedings of the NATO Advanced Study Institute, Erice, Italy, 4-15 June 2003
Series: Nato Science Series II: (closed), Vol. 140
Katrusiak, Andrzej, McMillan, Paul (Eds.)
DOI: 10.1007/978-1-4020-2102-2_7

Cover of the book: "High Pressure Crystallography" Eds.:. A. Katrusiak, P. McMillan

Cover of the book: „High Pressure Crystallography” Eds.:. A. Katrusiak, P. McMillan

ISBN: 978-1-4020-1954-8 (Print) 978-1-4020-2102-2 (Online)