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Journal articles on the topic 'Crystal Polymorphism'

Author: Grafiati

Published: 4 June 2021

Last updated: 6 September 2023

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1

Yang, Yuxin, Jia Liu, Anna Hu, Ting Nie, Zeneng Cheng, and Wenjie Liu. "A Critical Review on Engineering of d-Mannitol Crystals: Properties, Applications, and Polymorphic Control." Crystals 12, no. 8 (2022): 1080. http://dx.doi.org/10.3390/cryst12081080.

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d-mannitol is a common six-carbon sugar alcohol, which is widely used in food, chemical, pharmaceutical, and other industries. Polymorphism is defined as the ability of materials to crystallize into different crystal structures. It has been reported for a long time that d-mannitol has three polymorphs: β, δ, and α. These different polymorphs have unique physicochemical properties, thus affecting the industrial applications of d-mannitol. In this review, we firstly introduced the characteristics of different d-mannitol polymorphs, e.g., crystal structure, morphology, molecular conformational en

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2

G, Nithya, Sudha R, and Charles C. Kanakam. "Polymorphic behavior of an organic compound." Asian Journal of Pharmaceutical and Clinical Research 10, no. 4 (2017): 259. http://dx.doi.org/10.22159/ajpcr.2017.v10i4.16702.

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Objective: Polymorphic crystals were exhibited in many organic compounds. The frequency changes, relative intensities, band contours, and numberof bands were observed in the spectra of different polymorphism which may be due to molecule-molecule interactions in the crystal unit cells. Theshape of a molecule at its site in the unit cell is distorted by molecular interactions.Methods: The identification of a pure crystal form and to quantify a mixture of two forms infrared and Raman spectra of different crystalline formsof the same organic compound can be used. 2’-chloro-4-methoxy-3-nitro benzil

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3

Kersten, Kortney, Ramanpreet Kaur, and Adam Matzger. "Survey and analysis of crystal polymorphism in organic structures." IUCrJ 5, no. 2 (2018): 124–29. http://dx.doi.org/10.1107/s2052252518000660.

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With the intention of producing the most comprehensive treatment of the prevalence of crystal polymorphism among structurally characterized materials, all polymorphic compounds flagged as such within the Cambridge Structural Database (CSD) are analysed and a list of crystallographically characterized organic polymorphic compounds is assembled. Classifying these structures into subclasses of anhydrates, salts, hydrates, non-hydrated solvates and cocrystals reveals that there are significant variations in polymorphism prevalence as a function of crystal type, a fact which has not previously been

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4

Surov, Artem O., Katarzyna A. Solanko, Andrew D. Bond, Annette Bauer-Brandl, and German L. Perlovich. "Polymorphism of felodipine co-crystals with 4,4′-bipyridine." CrystEngComm 16, no. 29 (2014): 6603–11. http://dx.doi.org/10.1039/c4ce00756e.

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The calcium-channel blocking agent felodipine forms co-crystals with 4,4′-bipyridine with 1 : 1 and 2 : 1 molar ratios. The co-crystal with 1 : 1 molar ratio exists in two polymorphic forms. The co-crystals polymorphism was investigated by X-ray diffraction, DSC, solution calorimetry and Hirshfeld surfaces analysis.

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5

Schmidtmann, Marc, Derek S. Middlemiss, and Chick C. Wilson. "Isotopomeric polymorphism in a “doubly-polymorphic” multi-component molecular crystal." CrystEngComm 17, no. 28 (2015): 5273–79. http://dx.doi.org/10.1039/c5ce00123d.

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Isotopomeric polymorphism is observed in complexes of isonicotinamide with oxalic acid, highly unusual here in that each isotopic complex is itself polymorphic, a situation of “double polymorphism”. The four polymorphic forms exhibit different degrees of hydron transfer.

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Dabić, Predrag, Marko G. Nikolić, Sabina Kovač, and Aleksandar Kremenović. "Polymorphism and photoluminescence properties of K3ErSi2O7." Acta Crystallographica Section C Structural Chemistry 75, no. 10 (2019): 1417–23. http://dx.doi.org/10.1107/s2053229619011926.

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Two polymorphs of tripotassium erbium disilicate, K3ErSi2O7, were synthesized by high-temperature flux crystal growth during the exploration of the flux technique for growing new alkali rare-earth elements (REE) containing silicates. Their crystal structures were determined by single-crystal X-ray diffraction analysis. One of them (denoted 1) crystallizes in the space group P63/mmc and is isostructural with disilicates K3LuSi2O7, K3ScSi2O7 and K3YSi2O7, while the other (denoted 2) crystallizes in the space group P63/mcm and is isostructural with disilicates K3NdSi2O7, K3REESi2O7 (REE = Gd–Yb),

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7

Ghazani, Saeed M., and Alejandro G. Marangoni. "Molecular Origins of Polymorphism in Cocoa Butter." Annual Review of Food Science and Technology 12, no. 1 (2021): 567–90. http://dx.doi.org/10.1146/annurev-food-070620-022551.

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Cocoa butter displays complex crystallization behavior and six crystal polymorphic forms. Although the crystal structure of cocoa butter has been studied extensively, the molecular interactions between cocoa butter triacylglycerols in relation to polymorphic transformations from metastable forms (forms III and IV) to stable crystal forms (forms V and VI) remain largely unknown. In this review, the triclinic polymorphism and melting profiles of the major triacylglycerols in cocoa butter—POP, POS, and SOS—are reviewed, and their binary and ternary phase behaviors in metastable (pseudoβ′) and sta

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8

Akune, Yoko, Risa Hirosawa, Atsushi Koseki, and Shinya Matsumoto. "Role of halogen substituents in a series of polymorphic 2,5-diamino-3,6-dicyanopyrazine derivatives with highly flexible groups." Zeitschrift für Kristallographie - Crystalline Materials 232, no. 5 (2017): 395–405. http://dx.doi.org/10.1515/zkri-2016-2007.

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AbstractThe crystal structures of the ortho-X-benzyl derivatives, where X=F, Cl, Br, I, and Me, of 2,5-bis(N,N-dibenzylamino)-3,6-dicyanopyrazine dyes (C34H24N6X4) were analysed to evaluate the effect of a systematic series of structures on the occurrence of polymorphism. Detailed crystal structure analysis indicated that the thermally stable forms of the polymorphic derivatives (Cl and Br derivatives) were close-packed, whereas those of the non-polymorphic derivatives (F and I derivatives) were stabilised by an intermolecular interaction involving the ortho-substituents. In the thermally meta

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9

Kant, Rajni. "Pharmaceutical Drug Polymorphism: A Case Study of Three Novel Drugs." Acta Crystallographica Section A Foundations and Advances 70, a1 (2014): C544. http://dx.doi.org/10.1107/s2053273314094558.

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Polymorphism is more widespread in pharmaceutical solids, with estimates of 30-50% in drug-like molecules, compared to 4-5% polymorphic crystals in the Cambridge Structural Database (Nangia, 2007). Most of the drug molecules are formulated and marketed in crystalline form and many of these are highly functionalized and can self-organize in several ways in the solid state with nearly the same lattice energies. Though a lot of work is going on in the field of pharmaceutical drug polymorphism and its possible application in the field of crystal engineering, yet there are difficulties in getting p

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10

Parambil, Jose V., Sendhil K. Poornachary, Jerry Y. Y. Heng, and Reginald B. H. Tan. "Template-induced nucleation for controlling crystal polymorphism: from molecular mechanisms to applications in pharmaceutical processing." CrystEngComm 21, no. 28 (2019): 4122–35. http://dx.doi.org/10.1039/c9ce00404a.

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The major factors governing template-induced nucleation of molecular crystals are assessed, highlighting applications in pharmaceutical manufacturing and formulation processes where the templating effect is used to promote crystal nucleation and for controlling crystal polymorphism.

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11

Iwanaga, Hiroshi, Takeshi Hashishin, Seiji Motojima, Masaki Ichihara, and Shin Takeuchi. "Polymorphism in ZrP crystal." Journal of Materials Research 18, no. 3 (2003): 567–70. http://dx.doi.org/10.1557/jmr.2003.0073.

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Electron microscopy observations of α–ZrP whiskers with the NaCl structure, grown by chemical vapor deposition at 1300 °C, showed that there exists a hexagonal structure region (a = 0.369 nm and c = 1.248 nm) near the surface of the whiskers. High-resolution lattice image observations revealed that the method of stacking the eight-layered hexagonal structure is different from the reported hexagonal β–ZrP. In addition to the eight-layered structure, 12-layered and 16-layered structures were also observed, indicating a variety of ZrP polymorphisms.

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12

Kitagawa, J., R. Yada, M. Ichihara, and M. Ishikawa. "Crystal polymorphism in TmPd3S4." Results in Physics 3 (2013): 80–83. http://dx.doi.org/10.1016/j.rinp.2013.05.005.

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13

Fabianski, R., and B. Kuchta. "Polymorphism of cyanoadamantane crystal." Phase Transitions 76, no. 9-10 (2003): 815–21. http://dx.doi.org/10.1080/01411590310001613699.

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14

Yan, Tingting, Dongyang Xi, Qiuxue Fang, Ye Zhang, Junhai Wang, and Xiaodan Wang. "High-Pressure Polymorphism in Hydrogen-Bonded Crystals: A Concise Review." Crystals 12, no. 5 (2022): 739. http://dx.doi.org/10.3390/cryst12050739.

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High-pressure polymorphism is a developing interdisciplinary field. Pressure up to 20 GPa is a powerful thermodynamic parameter for the study and fabrication of hydrogen-bonded polymorphic systems. This review describes how pressure can be used to explore polymorphism and surveys the reports on examples of compounds that our group has studied at high pressures. Such studies have provided insight into the nature of structure–property relationships, which will enable crystal engineering to design crystals with desired architectures through hydrogen-bonded networks. Experimental methods are also

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15

Resel, Roland, Andrew O. F. Jones, Guillaume Schweicher, Roland Fischer, Nicola Demitri, and Yves Henri Geerts. "Polymorphism of terthiophene with surface confinement." IUCrJ 5, no. 3 (2018): 304–8. http://dx.doi.org/10.1107/s2052252518003949.

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The origin of unknown polymorphic phases within thin films is still not well understood. This work reports on crystals of the molecule terthiophene which were grown by thermal gradient crystallization using glass-plate substrates. The crystalline domains displayed a plate-like morphology with an extended lateral size of about 100 µm, but a thickness of only a few µm. Specular X-ray diffraction patterns confirmed the presence of a new polymorph of terthiophene. Crystal structure solution from a single crystal peeled from the film revealed a structure with an extremely large unit-cell volume con

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16

Steed, Jonathan W. "21st century developments in the understanding and control of molecular solids." Chemical Communications 54, no. 94 (2018): 13175–82. http://dx.doi.org/10.1039/c8cc08277d.

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17

Torubaev, Yury V., and Ivan V. Skabitsky. "Crystals at a Carrefour on the Way through the Phase Space: A Middle Path." Molecules 26, no. 6 (2021): 1583. http://dx.doi.org/10.3390/molecules26061583.

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Multiple supramolecular functionalities of cyclic α-alkoxy tellurium-trihalides (including Te---O, Te---X (X = Br, I) and Te---π(C=C) supramolecular synthons) afford rich crystal packing possibilities, which consequently results in polymorphism or Z’ > 1 crystal structures. Example of three crystal forms of cyclohexyl-ethoxy-tellurium-trihalides, one of which combines the packing of two others, affords a unique model to observe the supramolecular synthon evolution at the early stages of crystallization, when crystals on the way find themself at a carrefour between the evolutionally close ro

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18

Chattopadhyay, Basab, and Yves Geerts. "Substrate Induced Polymorphism in Organic Thin Films." Acta Crystallographica Section A Foundations and Advances 70, a1 (2014): C728. http://dx.doi.org/10.1107/s2053273314092717.

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The presence of substrate induced polymorphic phases in thin films is an intriguing phenomenon with the physical and chemical factors responsible for its formation are not yet clearly understood. In particular, this is really crucial in the field of organic electronics, where the charge-transport properties are highly dependent on crystal packing, especially for organic field-effect transistors where charge transport occurs at the interface between the organic semiconductor and the dielectric. In pharmaceutical sector, thin film drug delivery is the new emerging alternative to traditional tabl

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19

Yamada, Shigeyuki, Kazuki Kobayashi, Masato Morita та Tsutomu Konno. "D–π–A-type fluorinated tolanes with a diphenylamino group: crystal polymorphism formation and photophysical behavior". CrystEngComm 24, № 5 (2022): 936–41. http://dx.doi.org/10.1039/d1ce01671g.

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20

Nakagawa, Tomoyuki, Koji Nozaki, Shuichi Maeda, and Takashi Yamamoto. "Polymorphism of poly(nonamethyleneoxamide) crystal." Polymer 57 (January 2015): 99–104. http://dx.doi.org/10.1016/j.polymer.2014.12.022.

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21

Archala, Aneta, Wojciech Plazinski та Anita Plazinska. "The Val34Met, Thr164Ile and Ser220Cys Polymorphisms of the β2-Adrenergic Receptor and Their Consequences on the Receptor Conformational Features: A Molecular Dynamics Simulation Study". International Journal of Molecular Sciences 23, № 10 (2022): 5449. http://dx.doi.org/10.3390/ijms23105449.

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The gene encoding the β2-adrenergic receptor (β2-AR) is polymorphic, which results in possible differences in a primary structure of this protein. It has been shown that certain types of polymorphisms are correlated with some clinical features of asthma, including airways reactivity, whereas the influence of other is not yet understood. Among polymorphisms affecting amino acids at positions 16, 27, 34, 164 and 220, the latter three are present in the crystal structure of β2-AR, which facilitates studying them by means of molecular dynamics simulations. The current study was focused on investig

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22

Di Pumpo, Antonietta, Mark Weller, Sax Mason, and Marie-Hélène Lemée-Cailleau. "Hydrogen bonding structure and polymorphism in agrochemicals." Acta Crystallographica Section A Foundations and Advances 70, a1 (2014): C540. http://dx.doi.org/10.1107/s2053273314094595.

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Polymorphism of crystals, crystal habit and crystal growth are important factors that must be controlled for any commercial crystallization process. Pharmaceuticals and agrochemicals are two of the most industrially-important, active-molecule systems for which the physical properties are strongly correlated to their crystal structure. While pharmaceuticals have attracted more academic interest to date, the market for agrochemicals is also very considerable, amounting to $15 bn annually. Given the potential significant toxicity of some agrochemicals, the ability to control physical properties s

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23

Katrusiak, Andrzej. "Polymorphism of maleic hydrazide. I. Erratum." Acta Crystallographica Section B Structural Science 58, no. 3 (2002): 564. http://dx.doi.org/10.1107/s0108768102003506.

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In the recently published article by Katrusiak (2001) the crystal data of two polymorphs of maleic hydrazide have been printed with errors or omissions in Tables 1 and 2. It was the author's intention that the measurements of the unit-cell dimensions were possibly accurate, as the comparison of densities and unit-cell volumes of polymorphs are of particular importance. Therefore, these measurements were carried out at varied temperatures to eliminate possible differences owing to the thermal expansion of the crystals, and two different diffractometers, one with a point detector and another one

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24

Kaurova, I. A., D. M. Gorshkov, G. M. Kuz'micheva, and V. B. Rybakov. "COMPOSITION AND STRUCTURE OF THE HUNTITE-FAMILY COMPOUNDS." Fine Chemical Technologies 13, no. 6 (2018): 42–51. http://dx.doi.org/10.32362/2410-6593-2018-13-6-42-51.

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The literature data on the composition and structure of rare-earth borate compounds of the huntite family with the general composition LnM3(BO3)4, where Ln3+ = Y, La = Lu and M3+ = Al, Fe, Cr, Ga, Sc as well as a number of solid solutions with М3+ = Sc are systematized. The difference between the real compositions of crystals and the compositions of the initial mixture, the most characteristic of rare-earth scandium borates, is shown. The significant role of the composition in the manifestation of the compounds symmetry is established. The necessity of determining the crystals symmetry only on

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25

Strzhemechny, Mikhail A., Vyacheslav N. Baumer, Anatoli A. Avdeenko, Oleg S. Pyshkin, Roman V. Romashkin, and Lyubov M. Buravtseva. "Polymorphism of 4-bromobenzophenone." Acta Crystallographica Section B Structural Science 63, no. 2 (2007): 296–302. http://dx.doi.org/10.1107/s0108768106054334.

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A combination of single-crystal and powder X-ray diffractometry was used to study the structure of two polymorphs of 4-bromobenzophenone over the temperature range from 100 to 300 K. One of the polymorphs of the title compound was known previously and its structure has been determined at room temperature [Ebbinghaus et al. (1997). Z. Kristallogr. 212, 339–340]. Two crystal growth methods were employed, one of which (a modification of the Bridgman–Stockbarger technique) resulted in single crystals of a previously unknown structure. The basic physical properties of the stable polymorph are: grow

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26

Obata, Shigeaki, Mitsuaki Sato, and Hitoshi Goto. "Theoretical Prediction of Crystal Polymorphs for Organic Molecules." Acta Crystallographica Section A Foundations and Advances 70, a1 (2014): C1626. http://dx.doi.org/10.1107/s2053273314083739.

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Crystal structure prediction is one of the useful theoretical tools for designing and synthesizing new materials in pharmaceutical therapeutics and industrial electronics. Furthermore, the prediction can provide immense valuable scientific knowledge on a crystal growth, polymorphism and many properties of organic molecular crystals. Therefore, we have started the development of high-speed and high-accurate prediction method for organic molecular crystal structures [1,2]. In this work, we demonstrate the theoretical predictions of crystal structures of fourteen target molecules that were used i

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27

Bernstein, J. "Crystal growth, polymorphism and structure-property relationships in organic crystals." Journal of Physics D: Applied Physics 26, no. 8B (1993): B66—B76. http://dx.doi.org/10.1088/0022-3727/26/8b/010.

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28

Bulutoglu, Pelin Su, Conor Parks, Nandkishor K. Nere, Shailendra Bordawekar, and Doraiswami Ramkrishna. "Exploring New Crystal Structures of Glycine via Electric Field-Induced Structural Transformations with Molecular Dynamics Simulations." Processes 7, no. 5 (2019): 268. http://dx.doi.org/10.3390/pr7050268.

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Being able to control polymorphism of a crystal is of great importance to many industries, including the pharmaceutical industry, since the crystal’s structure determines significant physical properties of a material. While there are many conventional methods used to control the final crystal structure that comes out of a crystallization unit, these methods fail to go beyond a few known structures that are kinetically accessible. Recent studies have shown that externally applied fields have the potential to effectively control polymorphism and to extend the set of observable polymorphs that ar

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29

Khuu, Quang Chau, Giang Truong Dang, Huyen Thi Thanh Trinh, and Tuan Anh Nguyen. "Pharmaceutical crystallization in Couette-Taylor crystallizer: A case study of polymorphism of amino acid L-glutamic acid." Science and Technology Development Journal 19, no. 3 (2016): 11–23. http://dx.doi.org/10.32508/stdj.v19i3.580.

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The influence of intensity Taylor vortex flow in Couette-Taylor crystallizer on the crystallization of polymorphic amino acid L-glutamic acid was investigated in cooling crystallization. Here, the L-glutamic acid was chosen as the model crystal product, where it has two kinds of polymorphism including the unstable phase α-form and stable phase β-form crystal. In cooling crystallization, the α-form crystal transformed to the β-form crystal corresponding to the phase transformation of α-form to β-form crystal. The present study found that the selective polymorphism of α-form and β-form crystal a

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30

Walvekar, P. M. "POLYMORPHIC STUDIES OF FLUCONAZOLE IN DIFFERENT CRYSTAL SOLVATE FORMS AND ITS IMPLICATION ON BCS SOLUBILITY AND DISSOLUTION." INDIAN DRUGS 55, no. 05 (2018): 31–36. http://dx.doi.org/10.53879/id.55.05.10964.

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Fluconazole (anhydrate) is an anti-fungal agent which exists in various polymorphic forms. The present study is an attempt to obtain crystal solvates of fluconazole using various solvents and study its effect on polymorphic transformation and its implication on solubility and dissolution. fluconazole exhibits polymorphism and is poorly soluble in water, hence attempt was made to improve its solubility and dissolution. Crystal solvates of fluconazole were prepared in different solvents viz acetonitrile, methanol, propan-2-d and n-butanol. Polymorphic transformations were ascertained by subjecti

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31

Mu, Qiqi, Zhelin Ding, Yuyao Li, et al. "The Role of Polymorphism in Modulating Charge Transport Properties of Perylene-DTTCNQ Cocrystals." Advances in Engineering Technology Research 6, no. 1 (2023): 354. http://dx.doi.org/10.56028/aetr.6.1.354.2023.

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The charge transfer properties of organic molecular semiconductors are closely related to the accumulation of molecular crystals. Based on quantum nuclear tunneling model, the effect of polymorphs on the charge transport properties of binary charge-transfer complexes composed of perylene and 4,8-bis(dicyandiylidene)-4,8- dihydrobenzo[1,2-b:4,5-b']-dithiophene (DTTCNQ). Analysis of the reorganization energy of molecular crystals using the four-point (4P) method. Perylene was analyzed using the normal mode (NM) method, and the middle frequency around 1500 cm-1 made the largest contribution to th

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32

Endo, Takatsugu, Kozo Fujii, and Keiko Nishikawa. "Crystal Polymorphism of 1-Butyl-3-methylimidazolium Hexafluorophosphate: Phase Diagram, Structure, and Dynamics." Australian Journal of Chemistry 72, no. 2 (2019): 11. http://dx.doi.org/10.1071/ch18422.

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The ionic liquid (IL), 1-butyl-3-methylimidazolium hexafluorophosphate ([C4mim]PF6), is one of the most representative ILs. Despite its relatively simple ion structure and popularity, [C4mim]PF6 shows complex and confusing thermal phase behaviours, which stem from crystal polymorphism associated with cation conformational change and large thermal hysteresis. To the best of our knowledge, [C4mim]PF6 is the most investigated IL in terms of phase diagram, whereas full understanding has not yet been achieved due to its complexity. Here we review the current status of understanding of the phase dia

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33

Dubrovinsky, Leonid. "Polymorphism and electronic transformations of deep Earth minerals." Acta Crystallographica Section A Foundations and Advances 70, a1 (2014): C37. http://dx.doi.org/10.1107/s2053273314099628.

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While powder X-ray diffraction studies stepped over a megabar in pressure already in the 1970s, single crystal experiments remained much rarer and covered until recently a very limited pressure range barely reaching 15 GPa. Recent technological advances resulted in a revolutionary breakthrough in the high-pressure crystallography. The structure solution and the full refinement are now possible at pressures over 100 GPa. A comprehensive understanding of the iron- and aluminum-bearing magnesium silicate perovskite (Pv) and post-perovskite (PPv, CaIrO3-type) crystal structures and their evolution

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34

Braga, Dario, and Fabrizia Grepioni. "Making crystals from crystals: a green route to crystal engineering and polymorphism." Chemical Communications, no. 29 (2005): 3635. http://dx.doi.org/10.1039/b504668h.

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35

Ainurofiq, Ahmad, Kezia Esther Dinda, Maya Widia Pangestika, Ulia Himawati, Wening Dyah Wardhani, and Yustika Tamarin Sipahutar. "The effect of polymorphism on active pharmaceutical ingredients: A review." International Journal of Research in Pharmaceutical Sciences 11, no. 2 (2020): 1621–30. http://dx.doi.org/10.26452/ijrps.v11i2.2044.

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Active pharmaceutical ingredients (API) are the main components in the production process of pharmaceutical products. If the API has a good quality, then it will lead to good pharmaceutical products. API consists of more than one different crystal form which, then forms a polymorph through the process of polymorphism. Until now, API polymorphism is still a big challenge in the pharmaceutical industry. That is because the nature of polymorphism is difficult to predict. One of them is by crystallizing molecules in one or many crystalline forms or combining with other molecules to form stable co-

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Eventova, Varvara A., Konstantin V. Belov, Sergey V. Efimov, and Ilya A. Khodov. "Conformational Screening of Arbidol Solvates: Investigation via 2D NOESY." Pharmaceutics 15, no. 1 (2023): 226. http://dx.doi.org/10.3390/pharmaceutics15010226.

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Understanding of the nucleation process’s fundamental principles in saturated solutions is an urgent task. To do this task, it is necessary to control the formation of polymorphic forms of biologically active compounds. In certain cases, a compound can exist in a single polymorphic form, but have several solvates which can appear in different crystal forms, depending on the medium and conditions of formation, and show different pharmaceutical activity. In the present paper, we report on the analysis of Arbidol conformational preferences in two solvents of different polarities—deuterated chloro

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Yang, Jingxiang, Chunhua T. Hu, Ethan Reiter, and Bart Kahr. "Ambient l-lactic acid crystal polymorphism." CrystEngComm 23, no. 14 (2021): 2644–47. http://dx.doi.org/10.1039/d1ce00285f.

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The second and third crystalline forms of lactic acid are described, yet along with the known structure, they together fail to reproduce any of the supramolecular aggregates that have long been observed in isotropic media.

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38

Lee, Alfred Y., Deniz Erdemir, and Allan S. Myerson. "Crystal Polymorphism in Chemical Process Development." Annual Review of Chemical and Biomolecular Engineering 2, no. 1 (2011): 259–80. http://dx.doi.org/10.1146/annurev-chembioeng-061010-114224.

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39

Park, Hyunsoo, Jacques Barbier, and Robert P. Hammond. "Crystal structure and polymorphism of PbAlBO4." Solid State Sciences 5, no. 4 (2003): 565–71. http://dx.doi.org/10.1016/s1293-2558(03)00056-6.

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Panchagnula, Ramesh, Sonia Bedi, and Ashokraj Yasvanth. "Rifampicin Dissolution: Polymorphism or Crystal Defects." Clinical Research and Regulatory Affairs 23, no. 2 (2006): 71–83. http://dx.doi.org/10.1080/10601330600718939.

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41

Petruševski, Gjorgji, Marija Zbačnik, Marina Kajdžanoska, et al. "Pholcodine monohydrate: Crystal structure and polymorphism." Journal of Crystal Growth 375 (July 2013): 119–24. http://dx.doi.org/10.1016/j.jcrysgro.2013.04.031.

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42

Wantha, Lek. "Kinetics of the Solution-Mediated Polymorphic Transformation of Organic Compounds." Current Pharmaceutical Design 24, no. 21 (2018): 2383–93. http://dx.doi.org/10.2174/1381612824666180601093228.

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Polymorphism is a behavior of a substance to crystallize into more than one district crystal structures. Preferential formation of a polymorph depends strongly on the kinetics of the relevant mechanisms. Solutionmediated polymorphic transformation is an important mechanism in crystallization of organic compounds from solution. Knowing its kinetics allows us to understand the process and control the polymorphic formation. In this review, concepts, kinetics, and process modeling of crystallization and solution-mediated polymorphic transformation are examined and summarized.

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Ivanenko, Alisa, Vasily Minkov, Boris Zakharov, et al. "Study of structural response of chlorpropamide polymorphs to external stress." Acta Crystallographica Section A Foundations and Advances 70, a1 (2014): C269. http://dx.doi.org/10.1107/s2053273314097307.

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Polymorphism in molecular crystals is a remarkable property of Nature to create a wide range of various combinations of limited amount of components. Studies of the polymorphic crystals upon different types of external influence could be very useful in terms of analysis of molecular packing, nature and dynamics of the intermolecular interactions. When applied to pharmaceuticals, crystal structure may noticeably affect on stability, solubility, bioavailability, etc. which are essential for drug development. Sulfonyl urea derivatives represent a great example of compounds which are potentially i

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Pavlyuk, Volodymyr, Ihor Chumak, and Helmut Ehrenberg. "Polymorphism of Li2Zn3." Acta Crystallographica Section B Structural Science 68, no. 1 (2012): 34–39. http://dx.doi.org/10.1107/s0108768111053493.

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Crystal structures of low- and high-temperature modifications of the binary phase Li2Zn3 were determined by single-crystal X-ray diffraction techniques. The low-temperature modification is a disordered variant of Li5Sn2, space group R\bar 3m (No. 166). The high-temperature modification crystallizes as an anti-type to Li5Ga4, space group P\bar 3m1 (No. 164). Two polymorphs can be described as derivative structures to binary Li5Ga4, Li5Sn2, Li13Sn5, Li8Pb3, CeCd2 and CdI2 phases which belong to class 2 with the parent W-type in Krypyakevich's classification. All atoms in both polymorphs are coor

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Pogoda, Dorota, Jan Janczak, and Veneta Videnova-Adrabinska. "New polymorphs of an old drug: conformational and synthon polymorphism of 5-nitrofurazone." Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials 72, no. 2 (2016): 263–73. http://dx.doi.org/10.1107/s2052520615024956.

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Two new polymorphic forms of 5-nitrofurazone (5-nitro-2-furaldehyde semicarbazone) have been synthesized and structurally characterized by single-crystal and powder X-ray diffraction methods, vibrational spectroscopy (FT–IR and temperature Raman), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and Hirshfeld surface analysis. The compound crystallizes in three different polymorphic formsP21/a(polymorph α),P21(polymorph β) andP21/c(polymorph γ), the crystal structures of two of which (polymorphs β and γ) represent new structure determinations. The solid-state molecular

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Ghosh, Subhadip, and Arun Roy. "Crystal polymorphism of 8OCB liquid crystal consisting of strongly polar rod-like molecules." RSC Advances 11, no. 9 (2021): 4958–65. http://dx.doi.org/10.1039/d0ra08543j.

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Lai, Liming, Bing Fang, Wenyu Cheng, Pengyu Li, Yantu Zhang, and Meizhen Yin. "AIEgen based polymorphs with solvent regulated crystal-to-crystal switch properties." Materials Chemistry Frontiers 4, no. 6 (2020): 1773–80. http://dx.doi.org/10.1039/d0qm00154f.

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An AIEgen with tunable polymorphism-dependent emission and solvent regulated crystal-to-crystal switch properties is reported. Our study has provided insight into the relationship between molecular stacking and emission properties.

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Bochkova, T. M., M. P. Trubitsyn, M. D. Volnianskii, and D. M. Volnianskii. "Composition variations and UV irradiation effect on charge transfer in PbMoO4 single crystals." Journal of Physics and Electronics 30, no. 2 (2022): 45–48. http://dx.doi.org/10.15421/332217.

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The effect of nonstoichiometry of the composition, PbO polymorphism, and preliminary irradiation with ultraviolet light on electrical conductivity of alternating current (AC) was studied in PbMoO4 crystals. The crystals were grown by Czochralski method in a direction deviated by 30° from a-axis in (001) plain. The charge was prepared from MoO3 and PbO, lead oxide was used of α- or β- structural modifications. The reagents were taken both in a stoichiometric ratio and with an excess of 0.5 mol % of MoO3. It was shown that the magnitude of the dark and irradiation-induced AC conductivity was aff

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Liu, Chan, Jan Gerit Brandenburg, Omar Valsson, Kurt Kremer, and Tristan Bereau. "Free-energy landscape of polymer-crystal polymorphism." Soft Matter 16, no. 42 (2020): 9683–92. http://dx.doi.org/10.1039/d0sm01342k.

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Kniep, Rüdiger, Heinz Jürgen Beister, and Dieter Wald. "Polymorphie von Tellur(IV)-iodid/ Polymorphism of Tellurium(IV) Iodide." Zeitschrift für Naturforschung B 43, no. 8 (1988): 966–80. http://dx.doi.org/10.1515/znb-1988-0810.

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AbstractIdiomorphous crystals of five different polymorphic modifications (α-ε) of TeI4 are simultaneously grown from solutions of TeI4 and concentrated HI in methanol by evaporating the solvent at room temperature. δ-TeI4 is the only stable phase at normal conditions. Phase transformations of α-, β-, γ-and ε-TeI4 to the final stage δ-TeI4 take place by heating and run through discrete intermediates. The observed graduations lead to a sequence γ-, β-, α-,ε-TeI4 which indicates “increasing metastability”. The crystal structures of α-TeI4 (trigonal; P3̄ml; a = 4.228(2), c - 6.684(6)Å, Z = 0.5; D

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