Derivatives of 5-Morpholine-2-phenyl-3-pyridazinone

Katrusiak, Andrzej; Baloniak, S.

doi:10.1107/s0108767300026775

Cited by 6 publications

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“…An approach based on the analysis of the number and intensity of reflections forbidden by symmetry in the hightemperature phase with the space group R32, hexagonal setting (Hahn, 2006), was implemented to determine the temperature of the structural phase transition and compare the behaviour of such reflections with those in the previously studied (Y 0.95 Bi 0.05 )Fe 3 (BO 3 ) 4 compound. Our approach is equivalent to the one applied by Katrusiak (2000) but it is more suitable for inorganic crystals, in which the intensity of reflections varies considerably in magnitude.…”

Section: Analysis Of Systematic Extinctions In the R32 Space Group Asmentioning

confidence: 99%

Crystal structure and structural phase transition in bismuth-containing HoFe₃(BO₃)₄in the temperature range 11–500 K

Smirnova

Алексеева

Dudka

et al. 2019

Acta Crystallogr B Struct Sci Cryst Eng Mater

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An accurate single‐crystal X‐ray diffraction study of bismuth‐containing HoFe3(BO3)4 between 11 and 500 K has revealed structural phase transition at Tstr = 365 K. The Bi atoms enter the composition from Bi2Mo3O12‐based flux during crystal growth and significantly affect Tstr. The content of Bi was estimated by two independent methods, establishing the composition as (Ho0.96Bi0.04)Fe3(BO3)4. In the low‐temperature (LT) phase below Tstr the (Ho0.96Bi0.04)Fe3(BO3)4 crystal symmetry is trigonal, of space group P3121, whereas at high temperature (HT) above 365 K the symmetry increases to space group R32. There is a sharp jump of oxygen O1 (LT) and O2 (LT) atomic displacement parameters (ADP) at Tstr. O1 and O2 ADP ellipsoids are the most elongated over 90–500 K. In space group R32 specific distances decrease steadily or do not change with decreasing temperature. In space group P3121 the distortion of the polyhedra Ho(Bi)O6, Fe1O6 and Fe2O6, B2O3 and B3O3 increases with decreasing temperature, whereas the triangles B1O3 remain almost equilateral. All BO3 triangles deviate from the ab plane with decreasing temperature. Fe–Fe distances in Fe1 chains decrease, while distances in Fe2 chains increase with decreasing temperature. The Mössbauer study confirms that the FeO6 octahedra undergo complex dynamic distortions. However, all observed distortions are rather small, and the general change in symmetry during the structural phase transition has very little influence on the local environment of iron in oxygen octahedra. The Mössbauer spectra do not distinguish two structurally different Fe1 and Fe2 positions in the LT phase. The characteristic temperatures of cation thermal vibrations were calculated using X‐ray diffraction and Mössbauer data.

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Section: Analysis Of Systematic Extinctions In the R32 Space Group Asmentioning

confidence: 99%

Crystal structure and structural phase transition in bismuth-containing HoFe₃(BO₃)₄in the temperature range 11–500 K

Smirnova

Алексеева

Dudka

et al. 2019

Acta Crystallogr B Struct Sci Cryst Eng Mater

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“…Compression of materials facilitates close packing, molecular reorientations and rearrangements, and consequent variations in the nature of chemical bonding which can result in new structures and properties. Hydrogen‐bonded materials are found to undergo pressure‐induced structural changes with a wide range of variations in hydrogen bonds, from subtle rearrangements in the hydrogen bonding networks to drastic changes such as making and breaking of hydrogen bonds, proton disorder, symmetrization, etc . In the case of molecular solids with high carbon‐to‐hydrogen ratio, unsaturated bonds of the molecules tend to be saturated by linking to each other resulting in polymerization.…”

Section: Introductionmentioning

confidence: 99%

Hydrogen bonds and polymerization in acrylamide under pressure

Sharma

Murli

Sharma

2013

J Raman Spectroscopy

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Acrylamide (C3H5NO), a hydrogen‐bonded amide, is an important compound from the point of view of basic and material research. It can be used as a model system for studying hydrogen bonding interactions in amides under pressure. As it is a monomer of polyacrylamide, an important polymer, high pressure investigation of polymerization in this material is also of interest. Our in‐situ high pressure Raman spectroscopic investigations of acrylamide carried out up to 17 GPa under quasi‐hydrostatic conditions indicate possible structural variations through the reconstruction of the N‐H‐‐‐O hydrogen bonds at pressures above 2.6 GPa. Emergence of several new spectral features at higher pressures indicate onset of polymerization. The characteristic polymer band becomes discernible at ~17 GPa. The increase in the relative intensity of the polymer peaks with respect to the monomer peaks on release to ambient conditions suggests that higher fraction of polymer is obtained on decompression. Copyright © 2013 John Wiley & Sons, Ltd.

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“…There has also been an increasing interest in polymorphism (Bernstein, 2002) and phase changes in the solid state in order to understand the forces keeping crystals together. The study of mechanisms of phase transformations in organic crystals has recently drawn renewed interest with advances signi®cantly aided by the study of single-crystal-tosingle-crystal transformations (Hashizume et al, 2003;Botoshansky et al, 1998;Hostettler et al, 1999;Enjalbert & Galy, 2002;Katrusiak, 2000;Kaftory et al, 2001). This work focuses on polymorphism and phase transformations in OETCA.…”

Section: Introductionmentioning

confidence: 99%

A new polymorph of ortho-ethoxy-trans-cinnamic acid: single-to-single-crystal phase transformation and mechanism

Fernandes¹,

Levendis²,

Schoening³

2004

Acta Crystallogr Sect B

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The alpha-polymorph of ortho-ethoxy-trans-cinnamic acid (OETCA) undergoes a reversible single-crystal-to-single-crystal phase transformation at 333 K. The new high-temperature polymorph (alpha'-OETCA) is stable between 333 and 393 K with three molecules in the asymmetric unit (Z' = 3), space group P1;. Unlike the other polymorphs (and solvate) of OETCA recently reported, two of the molecules in alpha'-OETCA deviate significantly from planarity. This conformational change results in the corrugated sheet-type structure of alpha'-OETCA. The sheets are made up of ribbons, each composed of R(2)(2)(8) hydrogen-bonded pairs (via the -COOH groups), which are further connected by CH.O interactions. When exposed to UV radiation the alpha'-OETCA polymorph can be stabilized below 333 K with ca 8% of the monomer converted into the photodimer. The crystal structures of alpha'-OETCA are reported at two temperatures above the phase transition point (at 345 and 375 K) as well as the stabilized forms at 173 and 293 K. A mechanism for the phase transition involving a cooperative conformational transformation coupled with a shift of layers of OETCA molecules is proposed. The alpha'-OETCA polymorph is also an example of a cinnamic acid derivative where two different potentially photoreactive environments exist in one crystal in which each unit cell has two non-centrosymmetric predimer sites and one centrosymmetric predimer site.

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Derivatives of 5-Morpholine-2-phenyl-3-pyridazinone

Abstract: conference abstracts s320 ECM Nancy Acta Cryst. (2000). A56 (Supplement), s320 s9.m3.p9 A Novel Thiophosphorylated Cavitand and its Complex with

Cited by 6 publications

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Crystal structure and structural phase transition in bismuth-containing HoFe₃(BO₃)₄in the temperature range 11–500 K

Crystal structure and structural phase transition in bismuth-containing HoFe₃(BO₃)₄in the temperature range 11–500 K

Hydrogen bonds and polymerization in acrylamide under pressure

A new polymorph of ortho-ethoxy-trans-cinnamic acid: single-to-single-crystal phase transformation and mechanism

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Derivatives of 5-Morpholine-2-phenyl-3-pyridazinone

Abstract: conference abstracts s320 ECM Nancy Acta Cryst. (2000). A56 (Supplement), s320 s9.m3.p9 A Novel Thiophosphorylated Cavitand and its Complex with

Cited by 6 publications

References 0 publications

Crystal structure and structural phase transition in bismuth-containing HoFe3(BO3)4in the temperature range 11–500 K

Crystal structure and structural phase transition in bismuth-containing HoFe3(BO3)4in the temperature range 11–500 K

Hydrogen bonds and polymerization in acrylamide under pressure

A new polymorph of ortho-ethoxy-trans-cinnamic acid: single-to-single-crystal phase transformation and mechanism

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Crystal structure and structural phase transition in bismuth-containing HoFe₃(BO₃)₄in the temperature range 11–500 K

Crystal structure and structural phase transition in bismuth-containing HoFe₃(BO₃)₄in the temperature range 11–500 K