Modularity and three-dimensional isostructurality of novel synthons in sulfonamide–lactam cocrystals

Bolla, Geetha; Mittapalli, Sudhir; Nangia, Ashwini

doi:10.1107/s2052252515004960

Cited by 40 publications

(25 citation statements)

References 79 publications

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“…[18][19][20][21][22] Only recently, the biotechnological production of valerolactam (1) 23 and a lactam biosensor 24 have been introduced. So far, the molecular structure of 1 has only been described in respective co-crystals [25][26][27][28][29][30][31] and metal complexes. [32][33][34][35][36] Here, we describe for the first time a crystal structure of valerolactam (1) in the absence of other ligands, completing a homologous structural series of small and medium-sized lactams.…”

Section: Introductionmentioning

confidence: 99%

Missing Link in the Homologous Series of Lactams: The X-ray Structure of Valerolactam

Weck

Nauha

Gruber

2018

Crystal Growth & Design

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Lactams are an important class of heterocyclic compounds and are widely used for industrial and pharmaceutical purposes. Even decades after initial lactam syntheses, research on their physical and chemical properties is still rewarding. It delivers valuable information on the reactivity of lactams and their conformational behavior. For the small- and medium-sized parent lactams, the X-ray structures have been well-known, except for the “missing link”, the six-membered valerolactam. An X-ray structure of valerolactam is described here for the first time, stimulating a comparative discussion of the homologous lactam series. The experimental solid state conformation of valerolactam differs significantly from the calculated and energy-minimized ones reported in the literature. The amide bond length in valerolactam is more or less equal to that in other lactams. A comparison with the structure of cyclohexene revealed striking similarities arising from the partial C–N double bond in valerolactam caused by amide resonance.

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Section: Introductionmentioning

confidence: 99%

Missing Link in the Homologous Series of Lactams: The X-ray Structure of Valerolactam

Weck

Nauha

Gruber

2018

Crystal Growth & Design

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“…The design of novel supramolecular architectures utilizing non-covalent interactions in the development of novel pharmaceutical compounds is the current interest in crystal engineering. 1 It is important to understand the role of intermolecular interactions in the design of similar molecular arrangements having equivalent structural motifs in molecular crystals. 2 The control of the mutual arrangement of the molecules in the solid state to obtain the desired characteristics utilizing the intermolecular interactions is the art of crystal engineering.…”

Section: Introductionmentioning

confidence: 99%

“…3,4 According to the IUCr definition of isostructurality, "Two crystals are said to be isostructural if they have the same structure, but not necessarily the same unitcell dimensions nor the same chemical composition, with a comparable variability in the atomic coordinates to that of the cell dimensions and chemical composition". 5 It is of interest to study the phenomenon of isostructurality in isostructural polymorphs, [6][7][8][9][10][11] isostructural co-crystals 1,12,13 and isostructural solvates 14 on account of their applications in the pharmaceutical industry. [15][16][17][18][19][20] This behaviour is very common in similar related compounds having different types of structural equivalent functionalities like -H, -CH 3 , -F, -Cl, -Br and I.…”

Section: Introductionmentioning

confidence: 99%

Occurrence of 3D isostructurality in fluorinated phenyl benzamidines

Dey

Chopra

2017

CrystEngComm

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In the current study, we report the existence of 3D isostructurality behaviour in pairs of isomeric molecules existing as E-Z isomers. The polymorphic forms E1 and E2 of (E)-2-fluoro-N′-(3-phenyl) benzimidamide are individually isostructural with (E)-2-fluoro-N′-phenylbenzimidamide and (E)-2-fluoro-N′-(2fluorophenyl) benzimidamide, respectively. Furthermore, a similar compound, (Z)-3-fluoro-N′-(4fluorophenyl) benzimidamide, is isostructural with (Z)-4-fluoro-N′-(4-fluorophenyl) benzimidamide. The structural feature has been analyzed in terms of the nature and energetics of the equivalent supramolecular building blocks associated with the presence of various intermolecular interactions in the crystal packing. The crystal packing similarities have been investigated quantitatively via XPac analysis and the energy vector model. It is noteworthy to observe the presence of a rarely observed N-H⋯F interaction which plays an important role in the crystal packing of [(Z)-3-fluoro-N′-(4-fluorophenyl) benzimidamide]/[(Z)-4-fluoro-N′-(4-fluorophenyl) benzimidamide]. The NCI isosurface signifies the "attractive" nature of the N-H⋯F and N-H⋯π interactions and the different types of C-H⋯F dimeric motifs. An analysis of the two-dimensional fingerprint plots also provides a quantitative understanding of the occurrence of isostructurality in these compounds.

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“…Crystal engineering evolved from an intersection of crystallography and chemistry, especially after the 1970s when it became much easier to determine crystal structures of small molecule solids. Today, crystal engineering employs crystallography, spectroscopy and computation; around 50 papers have appeared in IUCrJ that highlight all three approaches (see, for example, Aakerö y et al, 2015; Nalla et al, 2015;Gá ndara & Bennett, 2014;Bolla et al, 2015;Lecomte et al, 2015). It is interesting that the subject is seen as mature enough for ICSU to organize a project with IUCr and IUPAC to delineate a set of nomenclature guidelines for crystal engineering.…”

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confidence: 99%