Incommensurate Phase in Λ-cobalt (III) Sepulchrate Trinitrate Governed by Highly Competitive N−H⋅⋅⋅O and C−H⋅⋅⋅O Hydrogen Bond Networks

Title data

Dey, Somnath ; Schönleber, Andreas ; van Smaalen, Sander ; Morgenroth, Wolfgang ; Krebs Larsen, Finn:
Incommensurate Phase in Λ-cobalt (III) Sepulchrate Trinitrate Governed by Highly Competitive N−H⋅⋅⋅O and C−H⋅⋅⋅O Hydrogen Bond Networks.
In: Chemistry : a European Journal. Vol. 28 (2022) Issue 13 . - e202104151.
ISSN 1521-3765
DOI: https://doi.org/10.1002/chem.202104151

Official URL:

Abstract in another language

Phase transitions in molecular crystals are often determined by intermolecular interactions. The cage complex of [Co(C₁₂H₃₀N₈)]³⁺ ⋅ 3 NO₃⁻ is reported to undergo a disorder-order phase transition at T꜀₁≈133 K upon cooling. Temperature-dependent neutron and synchrotron diffraction experiments revealed satellite reflections in addition to main reflections in the diffraction patterns below T꜀₁. The modulation wave vector varies as function of temperature and locks in at T꜀₃≈98 K. Here, we demonstrate that the crystal symmetry lowers from hexagonal to monoclinic in the incommensurately modulated phases in T꜀₁<T<T꜀₃. Distinctive levels of competitions: trade-off between longer N−H⋅⋅⋅O and shorter C−H⋅⋅⋅O hydrogen bonds; steric constraints to dense C−H⋅⋅⋅O bonds give rise to pronounced modulation of the basic structure. Severely frustrated crystal packing in the incommensurate phase is precursor to optimal balance of intermolecular interactions in the lock-in phase.

Further data

Item Type:	Article in a journal
Refereed:	Yes
Keywords:	hydrogen bond; incommensurate modulation; phase transition; steric factors; twin domains
Institutions of the University:	Faculties > Faculty of Mathematics, Physics und Computer Science > Group Material Sciences > Chair Crystallography Faculties > Faculty of Mathematics, Physics und Computer Science > Group Material Sciences > Chair Crystallography > Chair Crystallography - Univ.-Prof. Dr. Sander van Smaalen Faculties Faculties > Faculty of Mathematics, Physics und Computer Science Faculties > Faculty of Mathematics, Physics und Computer Science > Group Material Sciences
Result of work at the UBT:	Yes
DDC Subjects:	500 Science > 530 Physics
Date Deposited:	06 Apr 2022 07:22
Last Modified:	27 Jan 2023 08:52
URI:	https://eref.uni-bayreuth.de/id/eprint/69101