Investigations on the nucleation kinetics of γ-glycine single crystal

Yogambal, C.; Babu, D. Rajan; Vizhi, R. Ezhil

doi:10.1016/j.physb.2013.10.017

Cited by 12 publications

(5 citation statements)

References 19 publications

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“…Most previous work reports that for crystallisation from aqueous solution near neutral pH, it is the metastable α polymorph that dominates. [4][5][6][7][8][9][10][11][12][13][14][15][16][17] Apart from varying pH, 10 γ glycine has been obtained by applying an electric field, 33 adding salts 34,35 or in emulsion systems using the anionic surfactant AOT. 6,7 It is unusual to observe γ glycine without using one of these methods specifically to induce γ nucleation.…”

Section: Introductionmentioning

confidence: 99%

“…While undertaking our experiments, we were surprised to find that except for the fast nucleating samples the majority of our crystals were of the equilibrium γ polymorph. Most previous work reports that for crystallization from aqueous solution near neutral pH it is the metastable α polymorph that dominates. − Apart from varying pH, γ glycine has been obtained by applying an electric field, adding salts, , or in emulsion systems using the anionic surfactant AOT. , It is unusual to observe γ glycine without using one of these methods specifically to induce γ nucleation. Our findings may be useful because the pharmaceutical industry often wants the equilibrium polymorph, and we found it without varying the pH, adding salt, or other methods.…”

Section: Introductionmentioning

confidence: 99%

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Does the γ Polymorph of Glycine Nucleate Faster? A Quantitative Study of Nucleation from Aqueous Solution

Little

Sear

Keddie

2015

Crystal Growth & Design

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We quantitatively study the crystallisation of glycine from solution, by following the crystallisation of a plate with 96 wells, each with 0.1 ml of supersaturated solution. Our first aim is to address the difficult problem of obtaining nucleation data that is reproducible. This problem is difficult due to the extreme sensitivity of nucleation times. Nucleation is sensitive to factors that include how the crystallising system is prepared, and even small (1%) variations in the supersaturation. We discuss the appropriate statistical tests needed to show reproducibility.Our second aim is to study the competition between the nucleation of the alpha and gamma polymorphs of glycine. We find that nucleation appears to be heterogeneous: some samples crystallise in minutes, while others do not crystallise after days, which indicates that there is no well defined nucleation rate for the set of samples. Homogeneous nucleation gives a well-defined rate. Those samples that crystallise in minutes mostly yield the metastable alpha polymorph. We speculate that these crystals may be the result of seed crystals formed by transient local increases in supersaturation in pipette tips during sample preparation. However, those that crystallise in hours are largely in the equilibrium gamma polymorph. This is perhaps surprising as typically the alpha polymorph is obtained from crystallisation from aqueous solutions near neutral pH. We speculate that the nucleation rate of the gamma polymorph may be higher than that of the alpha form, but that in earlier work with larger solution volumes (increasing the probability of seeding) and with stirring, the alpha polymorph dominates because of its much faster growth rate.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Does the γ Polymorph of Glycine Nucleate Faster? A Quantitative Study of Nucleation from Aqueous Solution

Little

Sear

Keddie

2015

Crystal Growth & Design

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“…When the supersaturation exceeds the metastable limit, nucleation occurs spontaneously. This metastable zone is very important in the process of crystallization because it plays a key role in nucleation . However, there is no experimental data yet on the metastable zone of cephradine.…”

Section: Introductionmentioning

confidence: 99%

Determination of Nucleation Kinetics of Cephradine in 0.5% Sodium Bisulfate (W/V) Solution

Sun

Jiang

Liu

2017

Crystal Research and Technology

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The metastable zone width of cephradine in a 0.5% sodium bisulfate (W/V) solution was determined at different values of pH and temperatures by using dynamic laser monitoring under atmospheric pressure. As the pH increased, the metastable zone width of cephradine decreased before increasing, with a minimum value at the isoelectric point. The effect of temperature was less pronounced. The induction periods of cephradine in the 0.5% sodium bisulfate (W/V) solution were investigated as a function of the supersaturation ratio. By applying classical homogeneous nucleation theory, we deduced the crystal-liquid interfacial tension and the following fundamental nucleation parameters: the Gibbs free energy change for the formation of the critical nucleus, the radius of the critical nucleus, and the number of molecules in the critical nucleus.

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“…Glycine is used in stabilization applications, pharmaceutical applications and as a chemical intermediate. 17 The rst synthesis of squaric acid was published in 1959 by Cohen et al Squaric acid (IUPAC name 3,4-dihydroxycyclobut-3ene-1,2-dione) is a resourceful organic molecule that is used in a variety of elds in organic, inorganic chemistry and optoelectronic materials to bioconjugates. 18 Squaric acid has strong intermolecular hydrogen bonds due to its high melting point of 275-300 C and the low water-solubility.…”

Section: Introductionmentioning

confidence: 99%

Growth, crystal structure, Hirshfeld surface, dielectric and mechanical properties of a new organic single crystal: ‘Bis glycine’ squarate

et al. 2016

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Investigations on the nucleation kinetics of γ-glycine single crystal

Cited by 12 publications

References 19 publications

Does the γ Polymorph of Glycine Nucleate Faster? A Quantitative Study of Nucleation from Aqueous Solution

Does the γ Polymorph of Glycine Nucleate Faster? A Quantitative Study of Nucleation from Aqueous Solution

Determination of Nucleation Kinetics of Cephradine in 0.5% Sodium Bisulfate (W/V) Solution

Growth, crystal structure, Hirshfeld surface, dielectric and mechanical properties of a new organic single crystal: ‘Bis glycine’ squarate

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