High-Energy X-Ray Structure Determinations Using Synchrotron Radiation. Part 3. Self-Assembly of a Lacunary α-Keggin Undecatungstophosphate into a Three-Dimensional Network Linked by s-Block Cations.

This paper deals with the very great changes in X–ray crystallographic techniques and apparatus over a period of approximately the last 60 years. This is not a general history; it is a personal account of the developments with which I have been directly involved; it is, therefore, biased towards apparatus developments in the field of macromolecular crystallography in which I have worked during most of this period. The bias needs little excuse: many of the new techniques of X–ray crystallography were devised initially for large–molecule structure determinations which had most need of such advances in order to be feasible at all. Among them are the uses of computers in calculating electron density maps, the construction of automatic diffractometers and microdensitometers, the introduction of rotating-anode X–ray generators and of microfocus X–ray tubes, the development of electronic X–ray area detectors, the pioneering work on the use of synchrotron radiation for diffraction studies, the building of three–dimensional atomic models by computer and the complete automation of the mounting, selection and alignment of crystals on the diffractometer.

Download Full-text

Crystal structure of 3,14-dimethyl-2,6,13,17-tetraazoniatricyclo[16.4.0.07,12]docosane tetrachloride tetrahydrate from synchrotron X-ray data

Acta Crystallographica Section E Crystallographic Communications ◽

10.1107/s2056989018009337 ◽

2018 ◽

Vol 74 (8) ◽

pp. 1039-1041

Author(s):

Dohyun Moon ◽

Jong-Ha Choi

Keyword(s):

Crystal Structure ◽

Hydrogen Bonding ◽

Synchrotron Radiation ◽

Three Dimensional ◽

Water Molecules ◽

Inversion Symmetry ◽

Asymmetric Unit ◽

Intermolecular Hydrogen Bonds ◽

X Ray ◽

Dimensional Network

The crystal structure of the title salt, C20H44N4 4+·4Cl−·4H2O, has been determined using synchrotron radiation at 220 K. The structure determination reveals that protonation has occurred at all four amine N atoms. The asymmetric unit contains one half-cation (completed by crystallographic inversion symmetry), two chloride anions and two water molecules. There are two molecules in the unit cell. The Cl− anions and hydrate molecules are involved in hydrogen bonding. The crystal structure is stabilized by intermolecular hydrogen bonds involving the macrocycle N—H groups and water O—H groups as donors and the O atoms of the water molecules and the Cl− anions as acceptors, giving rise to a three-dimensional network.

Download Full-text

Crystal structure of 3,14-diethyl-2,6,13,17-tetraazoniatricyclo[16.4.0.07,12]docosane tetrachloride tetrahydrate from synchrotron X-ray data

Acta Crystallographica Section E Crystallographic Communications ◽

10.1107/s2056989021001006 ◽

2021 ◽

Vol 77 (2) ◽

pp. 213-216

Author(s):

Dohyun Moon ◽

Jong-Ha Choi

Keyword(s):

Crystal Structure ◽

Synchrotron Radiation ◽

Hydrogen Bonds ◽

Three Dimensional ◽

Water Molecules ◽

Inversion Symmetry ◽

Asymmetric Unit ◽

Intermolecular Hydrogen Bonds ◽

X Ray ◽

Dimensional Network

The crystal structure of the hydrated title salt, C22H48N4 4+·4Cl−·4H2O (C22H48N4 = H4 L = 3,14-diethyl-2,6,13,17-tetraazoniatricyclo[16.4.0.07,12]docosane), has been determined using synchrotron radiation at 220 K. The structure determination reveals that protonation has occurred at all four amine N atoms. The asymmetric unit comprises one half of the macrocyclic cation (completed by crystallographic inversion symmetry), two chloride anions and two water molecules. The macrocyclic ring of the tetracation adopts an exodentate (3,4,3,4)-D conformation. The crystal structure is stabilized by intermolecular hydrogen bonds involving the macrocycle N—H groups and water O—H groups as donors, and the O atoms of the water molecules and chloride anions as acceptors, giving rise to a three-dimensional network.

Download Full-text

Structural characterization, gelation ability, and energy-framework analysis of two bis(long-chain ester)-substituted 4,4′-biphenyl compounds

Acta Crystallographica Section C Structural Chemistry ◽

10.1107/s2053229617013237 ◽

2017 ◽

Vol 73 (10) ◽

pp. 791-796 ◽

Cited By ~ 4

Author(s):

David K. Geiger ◽

H. Cristina Geiger ◽

Shawn M. Moore ◽

William R. Roberts

Keyword(s):

Self Assembly ◽

Noncovalent Interactions ◽

Three Dimensional ◽

Framework Analysis ◽

Dimensional Network ◽

Dispersion Component ◽

Structure Determinations ◽

Phenyl Rings ◽

Alcohol Solvents ◽

Solid State Structures

There are few examples of single-crystal structure determinations of gelators, as gel formation requires that the dissolved gelator self-assemble into a three-dimensional network structure incorporating solvent via noncovalent interactions rather than self-assembly followed by crystallization. In the solid-state structures of the isostructural compounds 4,4′-bis[5-(methoxycarbonyl)pentyloxy]biphenyl (BBO6-Me), C26H34O6, and 4,4′-bis[5-(ethoxycarbonyl)pentyloxy]biphenyl (BBO6-Et), C28H38O6, the molecules sit on a crystallographically imposed center of symmetry, resulting in strictly coplanar phenyl rings. BBO6-Me behaves as an organogelator in various alcohol solvents, whereas BBO6-Et does not. The extended structure reveals bundles of molecules that form a columnar superstructure. Framework-energy calculations reveal much stronger interaction energies within the columns (−52 to −78 kJ mol−1) than between columns (−2 to −16 kJ mol−1). The intracolumnar interactions are dominated by a dispersion component, whereas the intercolumnar interactions have a substantial electrostatic component.

Download Full-text

Crystal structure of 3,14-dimethyl-2,13-diaza-6,17-diazoniatricyclo[16.4.0.07,12]docosane bis(perchlorate) from synchrotron X-ray data

Acta Crystallographica Section E Crystallographic Communications ◽

10.1107/s2056989021004278 ◽

2021 ◽

Vol 77 (5) ◽

pp. 551-554

Author(s):

Dohyun Moon ◽

Sunghwan Jeon ◽

Jong-Ha Choi

Keyword(s):

Crystal Structure ◽

Synchrotron Radiation ◽

Hydrogen Bonds ◽

Structure Determination ◽

Three Dimensional ◽

Asymmetric Unit ◽

X Ray ◽

Dimensional Network

The crystal structure of the title salt, C20H42N4 2+·2ClO4 −, has been determined using synchrotron radiation at 220 (2) K. The structure determination reveals that protonation has occurred at diagonally opposite amine N atoms. The asymmetric unit comprises one half of the organic dication, which lies about a center of inversion, and one perchlorate anion. The macrocyclic dication adopts the most stable endodentate trans-III conformation. The crystal structure is stabilized by intramolecular N—H...N, and intermolecular N—H...O and C–H...O hydrogen bonds involving the macrocycle N—H and C—H groups as donors and the O atoms of perchlorate anions as acceptors, giving rise to a three-dimensional network.

Download Full-text

X‐ray determination of the Debye temperature at high pressure using high‐energy synchrotron radiation

Journal of Applied Physics ◽

10.1063/1.346446 ◽

1990 ◽

Vol 68 (6) ◽

pp. 2719-2722 ◽

Cited By ~ 2

Author(s):

A. Matsumuro ◽

M. Kobayashi ◽

T. Kikegawa ◽

M. Senoo

Keyword(s):

High Pressure ◽

Synchrotron Radiation ◽

Debye Temperature ◽

High Energy ◽

X Ray

Download Full-text

Two- and Three-Dimensional Network of Nanoparticles via Polymer-Mediated Self-Assembly

ACS Macro Letters ◽

10.1021/mz200141q ◽

2012 ◽

Vol 1 (3) ◽

pp. 396-399 ◽

Cited By ~ 7

Author(s):

Mottakin M. Abul Kashem ◽

Debabrata Patra ◽

Jan Perlich ◽

André Rothkirch ◽

Adeline Buffet ◽

...

Keyword(s):

Self Assembly ◽

Three Dimensional ◽

Dimensional Network

Download Full-text

Crystal structures of tricalcium citrates

Powder Diffraction ◽

10.1017/s0885715618000283 ◽

2018 ◽

Vol 33 (2) ◽

pp. 98-107 ◽

Cited By ~ 3

Author(s):

James A. Kaduk

Keyword(s):

Crystal Structures ◽

Density Functional ◽

Three Dimensional ◽

Water Molecules ◽

Calcium Citrate ◽

Powder Diffraction Data ◽

Coordination Polyhedra ◽

X Ray ◽

Calcium Supplements ◽

Dimensional Network

The crystal structures of calcium citrate hexahydrate, calcium citrate tetrahydrate, and anhydrous calcium citrate have been solved using laboratory and synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Both the hexahydrate and tetrahydrate structures are characterized by layers of edge-sharing Ca coordination polyhedra, including triply chelated Ca. An additional isolated Ca is coordinated by water molecules, and two uncoordinated water molecules occur in the hexahydrate structure. The previously reported polymorph of the tetrahydrate contains the same layers, but only two H2O coordinated to the isolated Ca and two uncoordinated water molecules. Anhydrous calcium citrate has a three-dimensional network structure of Ca coordination polyhedra. The new polymorph of calcium citrate tetrahydrate is the major crystalline phase in several commercial calcium supplements.

Download Full-text

Investigation of Residual Stress/Strain and Texture in a Large Dissimilar Metal Weld Using Synchrotron Radiation and Neutrons

Materials Science Forum ◽

10.4028/www.scientific.net/msf.772.193 ◽

2013 ◽

Vol 772 ◽

pp. 193-199 ◽

Cited By ~ 1

Author(s):

Carsten Ohms ◽

Rene V. Martins

Keyword(s):

Synchrotron Radiation ◽

Neutron Diffraction ◽

Residual Stresses ◽

Large Scale ◽

High Energy ◽

X Ray Diffraction ◽

Butt Weld ◽

X Ray ◽

Component Size ◽

Thin Slice

Bi-metallic piping welds are frequently used in light water nuclear reactors to connect ferritic steel pressure vessel nozzles to austenitic stainless steel primary cooling piping systems. An important aspect for the integrity of such welds is the presence of residual stresses. Measurement of these residual stresses presents a considerable challenge because of the component size and because of the material heterogeneity in the weld regions. The specimen investigated here was a thin slice cut from a full-scale bi-metallic piping weld mock-up. A similar mock-up had previously been investigated by neutron diffraction within a European research project called ADIMEW. However, at that time, due to the wall thickness of the pipe, stress and spatial resolution of the measurements were severely restricted. One aim of the present investigations by high energy synchrotron radiation and neutrons used on this thin slice was to determine whether such measurements would render a valid representation of the axial strains and stresses in the uncut large-scale structure. The advantage of the small specimen was, apart from the easier manipulation, the fact that measurement times facilitated a high density of measurements across large parts of the test piece in a reasonable time. Furthermore, the recording of complete diffraction patterns within the accessible diffraction angle range by synchrotron X-ray diffraction permitted mapping the texture variations. The strain and stress results obtained are presented and compared for the neutron and synchrotron X-ray diffraction measurements. A strong variation of the texture pole orientations is observed in the weld regions which could be attributed to individual weld torch passes. The effect of specimen rocking on the scatter of the diffraction data in the butt weld region is assessed during the neutron diffraction measurements.

Download Full-text

Epitaxial Ni nanoparticles on CaF2(001), (110) and (111) surfaces studied by three-dimensional RHEED, GIXD and GISAXS reciprocal-space mapping techniques

Journal of Applied Crystallography ◽

10.1107/s160057671700512x ◽

2017 ◽

Vol 50 (3) ◽

pp. 830-839 ◽

Cited By ~ 4

Author(s):

S. M. Suturin ◽

V. V. Fedorov ◽

A. M. Korovin ◽

N. S. Sokolov ◽

A. V. Nashchekin ◽

...

Keyword(s):

Lattice Structure ◽

Three Dimensional ◽

Grazing Incidence ◽

High Energy ◽

Reciprocal Space ◽

Mapping Technique ◽

Face Centered Cubic ◽

X Ray ◽

Cubic Lattice ◽

Face Centered

The development of growth techniques aimed at the fabrication of nanoscale heterostructures with layers of ferroic 3dmetals on semiconductor substrates is very important for their potential usage in magnetic media recording applications. A structural study is presented of single-crystal nickel island ensembles grown epitaxially on top of CaF2/Si insulator-on-semiconductor heteroepitaxial substrates with (111), (110) and (001) fluorite surface orientations. The CaF2buffer layer in the studied multilayer system prevents the formation of nickel silicide, guides the nucleation of nickel islands and serves as an insulating layer in a potential tunneling spin injection device. The present study, employing both direct-space and reciprocal-space techniques, is a continuation of earlier research on ferromagnetic 3dtransition metals grown epitaxially on non-magnetic and magnetically ordered fluorides. It is demonstrated that arrays of stand-alone faceted nickel islands with a face-centered cubic lattice can be grown controllably on CaF2surfaces of (111), (110) and (001) orientations. The proposed two-stage nickel growth technique employs deposition of a thin seeding layer at low temperature followed by formation of the islands at high temperature. The application of an advanced three-dimensional mapping technique exploiting reflection high-energy electron diffraction (RHEED) has proved that the nickel islands tend to inherit the lattice orientation of the underlying fluorite layer, though they exhibit a certain amount of {111} twinning. As shown by scanning electron microscopy, grazing-incidence X-ray diffraction (GIXD) and grazing-incidence small-angle X-ray scattering (GISAXS), the islands are of similar shape, being faceted with {111} and {100} planes. The results obtained are compared with those from earlier studies of Co/CaF2epitaxial nanoparticles, with special attention paid to the peculiarities related to the differences in lattice structure of the deposited metals: the dual-phase hexagonal close-packed/face-centered cubic lattice structure of cobalt as opposed to the single-phase face-centered cubic lattice structure of nickel.

Download Full-text