Redetermined crystal structure of α-<scp>DL</scp>-methionine at 340 K

Görbitz, Carl Henrik; Qi, Lianglin; Kim, Ngan Thi; Kristiansen, Håvard Anton

doi:10.1107/s1600536814022211

Cited by 21 publications

(24 citation statements)

References 11 publications

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“…The enantiotropically related polymorphs of the linearchain amino acid racemates are shown in Fig. 2 (Gö rbitz et al, 2012, 2014Gö rbitz, 2011;Coles et al, 2009;Smets et al, , 2017Xynogalas, 2003). In all structures, the molecules are arranged in bilayers that are held together by relatively strong hydrogen bonds between the zwitterionic amino and carboxylic acid groups (see Fig.…”

Section: Racematesmentioning

confidence: 99%

On the mechanism of solid-state phase transitions in molecular crystals – the role of cooperative motion in (quasi)racemic linear amino acids

Smets¹,

Kalkman²,

Krieger³

et al. 2020

Int Union Crystallogr J

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During single-crystal-to-single-crystal (SCSC) phase transitions, a polymorph of a compound can transform to a more stable form while remaining in the solid state. By understanding the mechanism of these transitions, strategies can be developed to control this phenomenon. This is particularly important in the pharmaceutical industry, but also relevant for other industries such as the food and agrochemical industries. Although extensive literature exists on SCSC phase transitions in inorganic crystals, it is unclear whether their classications and mechanisms translate to molecular crystals, with weaker interactions and more steric hindrance. A comparitive study of SCSC phase transitions in aliphatic linear-chain amino acid crystals, both racemates and quasi-racemates, is presented. A total of 34 transitions are considered and most are classified according to their structural change during the transition. Transitions without torsional changes show very different characteristics, such as transition temperature, enthalpy and free energy, compared with transitions that involve torsional changes. These differences can be rationalized using classical nucleation theory and in terms of a difference in mechanism; torsional changes occur in a molecule-by-molecule fashion, whereas transitions without torsional changes involve cooperative motion with multiple molecules at the same time.

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Section: Racematesmentioning

confidence: 99%

On the mechanism of solid-state phase transitions in molecular crystals – the role of cooperative motion in (quasi)racemic linear amino acids

Smets¹,

Kalkman²,

Krieger³

et al. 2020

Int Union Crystallogr J

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“…The crystal structures of amino acids with hydrophobic side chains invariably incorporate molecular bilayers, each with a hydrogen-bonded core and two surfaces shaped by the amino acid side chains. A series of unique solid-state phase transitions, involving sliding along the hydrophobic interfaces between adjacent bilayers, have been observed for dlmethionine (Met; Mathieson, 1952;Taniguchi et al, 1980;Alagar et al, 2005;Gö rbitz et al, 2014; Gö rbitz, 2014), dl-2-aminobutyric acid (Abu; Gö rbitz et al, 2012; Nakata et al, 1980;Voogd & Derissen, 1980;Akimoto & Iitaka, 1972;Ichikawa & Iitaka, 1968), dl-norvaline (Nva; Gö rbitz, 2011) and dl-norleucine (Nle; Coles et al, 2009;Harding et al, 1995;Dalhus & Gö rbitz, 1996b;Smets et al, 2015;van den Ende & Cuppen, 2014) as well as for the four quasiracemates l-Nva:d-Nle, l-Nva:d-Met, l-Nle:d-Met (Gö rbitz & Karen, 2015) and l-Abu:d-Met (Gö rbitz et al, 2016). Little is known by comparison about the corresponding enantiomeric amino acids.…”

Section: Introductionmentioning

confidence: 99%

An exceptional series of phase transitions in hydrophobic amino acids with linear side chains

Görbitz

Karen

Dušek

et al. 2016

IUCrJ

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“…In the crystal of (R,S)-HMTBA copper salt (Yang et al, 2015), a similar (t, t, g+) backbone rotamer exists in the (S)-HMTBA molecule. Likewise, the respective (t, t, g+) conformation of the l-methionine side chain was found in theisoform of dl-Met crystal (CCDC 1028063;Gö rbitz et al, 2014). The backbone conformation in (R)-(IB) is the gauche+, trans, gauche+ rotamer.…”

Section: Structural Commentarymentioning

confidence: 80%

Crystal structure of (R,S)-2-hydroxy-4-(methylsulfanyl)butanoic acid

Mawhinney

Chance

et al. 2020

Acta Crystallogr E Cryst Commun

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The title compound, a major animal feed supplement, abbreviated as HMTBA and alternatively called DL-methionine hydroxy analogue, C5H10O3S, (I), was isolated in pure anhydrous monomeric form. The melting point is 302.5 K and the compound crystallizes in the monoclinic space group P21/c, with two conformationally non-equivalent molecules [(I A ) and (I B )] in the asymmetric unit. The crystal structure is formed by alternating polar and non-polar layers running along the bc plane and features an extensive hydrogen-bonding network within the polar layers. The Hirshfeld surface analysis revealed a significant contribution of non-polar H...H and H...S interactions to the packing forces for both molecules.

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Redetermined crystal structure of α-DL-methionine at 340 K

Abstract: An accurate redetermination of α-dl-methionine provides coordinates for the H atoms, detailed hydrogen-bond geometries and reveals that the side chain is disordered over a major (95%) and a minor (5%) position.

Cited by 21 publications

References 11 publications

On the mechanism of solid-state phase transitions in molecular crystals – the role of cooperative motion in (quasi)racemic linear amino acids

On the mechanism of solid-state phase transitions in molecular crystals – the role of cooperative motion in (quasi)racemic linear amino acids

An exceptional series of phase transitions in hydrophobic amino acids with linear side chains

Crystal structure of (R,S)-2-hydroxy-4-(methylsulfanyl)butanoic acid

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Redetermined crystal structure of α-DL-methionine at 340 K

Abstract: An accurate redetermination of α-dl-me­thio­nine provides coordinates for the H atoms, detailed hydrogen-bond geometries and reveals that the side chain is disordered over a major (95%) and a minor (5%) position.

Cited by 21 publications

References 11 publications

On the mechanism of solid-state phase transitions in molecular crystals – the role of cooperative motion in (quasi)racemic linear amino acids

On the mechanism of solid-state phase transitions in molecular crystals – the role of cooperative motion in (quasi)racemic linear amino acids

An exceptional series of phase transitions in hydrophobic amino acids with linear side chains

Crystal structure of (R,S)-2-hydroxy-4-(methylsulfanyl)butanoic acid

Contact Info

Product

Resources

About

Abstract: An accurate redetermination of α-dl-methionine provides coordinates for the H atoms, detailed hydrogen-bond geometries and reveals that the side chain is disordered over a major (95%) and a minor (5%) position.