Determination of the Activation Energies of Phase Transition for Calcium Orthophosphates Based on Powder X‐Ray Diffraction Data

In this work, initial crystallographic studies of human haemoglobin (Hb) crystallized in isoionic and oxygen-free PEG solution are presented. Under these conditions, functional measurements of the O2-linked binding of water molecules and release of protons have evidenced that Hb assumes an unforeseen new allosteric conformation. The determination of the high-resolution structure of the crystal of human deoxy-Hb fully stripped of anions may provide a structural explanation for the role of anions in the allosteric properties of Hb and, particularly, for the influence of chloride on the Bohr effect, the mechanism by which Hb oxygen affinity is regulated by pH. X-ray diffraction data were collected to 1.87 Å resolution using a synchrotron-radiation source. Crystals belong to the space group P21212 and preliminary analysis revealed the presence of one tetramer in the asymmetric unit. The structure is currently being refined using maximum-likelihood protocols.

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Investigation and rationalisation of hydrogen bonding patterns in sulfonylamino compounds and related materials: crystal structure determination of microcrystalline solids from powder X-ray diffraction data

Journal of the Chemical Society Perkin Transactions 2 ◽

10.1039/p29930001625 ◽

1993 ◽

pp. 1625 ◽

Cited By ~ 8

Author(s):

Philip Lightfoot ◽

Maryjane Tremayne ◽

Christopher Glidewell ◽

Kenneth D. M. Harris ◽

Peter G. Bruce

Keyword(s):

Crystal Structure ◽

Hydrogen Bonding ◽

Diffraction Data ◽

Structure Determination ◽

Crystal Structure Determination ◽

X Ray Diffraction ◽

X Ray ◽

Bonding Patterns

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Rubidium tetrafluoridobromate(III): redetermination of the crystal structure from single-crystal X-ray diffraction data

IUCrData ◽

10.1107/s2414314619015955 ◽

2019 ◽

Vol 4 (11) ◽

Author(s):

Artem V. Malin ◽

Sergei I. Ivlev ◽

Roman V. Ostvald ◽

Florian Kraus

Keyword(s):

Crystal Structure ◽

Single Crystal ◽

Single Crystals ◽

Diffraction Data ◽

Structure Type ◽

X Ray Diffraction ◽

X Ray ◽

Square Planar ◽

Atomic Coordinates

Single crystals of rubidium tetrafluoridobromate(III), RbBrF4, were grown by melting and recrystallizing RbBrF4 from its melt. This is the first determination of the crystal structure of RbBrF4 using single-crystal X-ray diffraction data. We confirmed that the structure contains square-planar [BrF4]− anions and rubidium cations that are coordinated by F atoms in a square-antiprismatic manner. The compound crystallizes in the KBrF4 structure type. Atomic coordinates and bond lengths and angles were determined with higher precision than in a previous report based on powder X-ray diffraction data [Ivlev et al. (2015). Z. Anorg. Allg. Chem. 641, 2593–2598].

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