Concomitant Polymorphs

Bernstein, Joel; Davey, Roger J.; Henck, Jan‐Olav

doi:10.1002/(sici)1521-3773(19991203)38:23<3440::aid-anie3440>3.0.co;2-#

Cited by 818 publications

(689 citation statements)

References 65 publications

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“…In general, a polymorphic transition frequently occurs during crystallization from the supersaturated solutions of organic compounds, particularly when the packing mode in the first-formed crystal is metastable as the crystal structure [26][27][28][29][30]. Although much less is known about the mechanism of the polymorphic transition during crystallization from solution, it has been believed that the phase transition should proceed through either a solvent-mediated dissolution-recrystallization mechanism according to the 'Ostwald's law of stages' [31] or a solid-to-solid transformation one with the free energy change [32], and that the rate of the polymorphic transition primarily depends on the free energy difference between the two crystalline phases [26][27][28][29][30].…”

Section: Mechanism Of Preferential Enrichmentmentioning

confidence: 99%

“…Although much less is known about the mechanism of the polymorphic transition during crystallization from solution, it has been believed that the phase transition should proceed through either a solvent-mediated dissolution-recrystallization mechanism according to the 'Ostwald's law of stages' [31] or a solid-to-solid transformation one with the free energy change [32], and that the rate of the polymorphic transition primarily depends on the free energy difference between the two crystalline phases [26][27][28][29][30].…”

Section: Mechanism Of Preferential Enrichmentmentioning

confidence: 99%

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Chiral Symmetry Breaking Phenomenon Caused by a Phase Transition

2010

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Abstract:We report the mechanism and scope of "preferential enrichment", which is an unusual symmetry-breaking enantiomeric resolution phenomenon that is initiated by the solvent-assisted solid-to-solid transformation of a metastable polymorphic form into a thermodynamically stable one during crystallization from the supersaturated solution of certain kinds of racemic mixed crystals (i.e., solid solutions or pseudoracemates) composed of two enantiomers. The mechanism can well be interpreted in terms of a symmetrybreaking complexity phenomenon involving multistage processes that affect each other.

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Section: Mechanism Of Preferential Enrichmentmentioning

confidence: 99%

Section: Mechanism Of Preferential Enrichmentmentioning

confidence: 99%

Chiral Symmetry Breaking Phenomenon Caused by a Phase Transition

2010

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“…[1][2][3][4] Genuine structural polymorphs based on identical chemical compositions but different structures provide an invaluable opportunity to study crystal engineering of coordination chemistry on how a balance of energies between different interactions including coordination bond, hydrogen bond, and π···π interactions influences the selfassembly mechanism, crystal growth process and stabilities of the phases. [5] Especially, genuine structural polymorph derived from a one-pot reaction of the reactants under certain conditions is a typical system with many advantages for the study of the self-assembly and crystal growth processes.…”

Section: Introductionmentioning

confidence: 99%

Bond Order Analysis, Packing Ratio, and Electronic Structures of Two Structural Polymorphs Based on Manganese Complexes

Chen

Zhang

et al. 2017

Chin. J. Chem.

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The bond order and packing ratios in the single-crystal of the two structural polymorphs as well as the detailed electronic structures of the molecular model were studied using density functional theory. The strength of different Mn coordination bonds was analyzed in detail through Mayer bond order. Besides bond length, many other factors such as the orientation of ligand and nature of metal also significantly influence the bond order. Packing ratios calculated using cluster model reveals that packing along b direction in Dimer is more favorable than other directions due to the associated interactions of π-π and Cl…H when packing in this direction. Electronic structure helps explain the formation of Dimer from monomer or direct forming of Chain from ligand/Cl and metal. This would shed light on further understanding the importance of supramolecular interaction on crystal engineering.

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“…42c, 43 The composition was usually in favor of polymorph II (Figures 2, S6-S9), with the exception of the ca. fifty year old batch, which contained more of polymorph I.…”

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confidence: 99%

Solid-State Chemistry and Polymorphism of the Nucleobase Adenine

Stolar

Lukin

Požar

et al. 2016

Crystal Growth & Design

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The nucleobase adenine plays a pivotal role in the chemistry of life, but is also becoming increasingly interesting as a building block in the synthesis of functional solid materials.Although commercially available as a solid, adenine's solid-state chemistry has so far been neglected. In this comprehensive study it is shown that adenine is most often marketed as a mixture of two polymorphs, one previously known, and a new polymorph.Both polymorphs exhibit layered structures with different hydrogen-bonding patterns within layers. The crystal structure of the new polymorph was elucidated using synchrotron powder X-ray diffraction. Polymorph occurrence conditions, interconversion and the difference in their thermodynamic stability were established theoretically and experimentally revealing the polymorph with Z = 2 (known) as stable relative to the polymorph with Z = 1 (new). The adenine layers in both polymorphs are connected by weak interaction likely resulting in stacking faults which are manifested in anisotropic line broadening of their powder diffraction patterns. Analysis of a few commercial samples of adenine revealed them all to be a polymorph mixture, which could be inconvenient in experiments where properties of the solid material could be relevant.

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Concomitant Polymorphs

Cited by 818 publications

References 65 publications

Chiral Symmetry Breaking Phenomenon Caused by a Phase Transition

Chiral Symmetry Breaking Phenomenon Caused by a Phase Transition

Bond Order Analysis, Packing Ratio, and Electronic Structures of Two Structural Polymorphs Based on Manganese Complexes

Solid-State Chemistry and Polymorphism of the Nucleobase Adenine

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