Molecular and crystal structure of Ac-(Z)-ΔAbu-NMe2 and Ac-DL-Abu-NMe2 as compared to those of related molecules
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Dawid Siodłak
Abstract
The molecular and crystal structures of two homologous amino acid derivatives: N-acetyl-α,β-dehydro-butyrine N´,N´-dimethylamide (1) and N-acetyl-DL-butyrine N´,N´-dimethylamide (2), have been determined by X-ray crystallography. Similar solid-state association of both compounds is observed; despite different molecular conformation, they form centrosymmetric dimers linked by the intermolecular N–H…O hydrogen bonds. The conformation of two crystallographically independent molecules of 1 [with torsion angles ϕ, ψ, χ1 ≈ (–47°, 130°, 3°), respectively] is also characteristic of other related diamides – ΔAla, ΔPhe and ΔLeu – previously studied in the solid state. To analyse whether this conformation is rigid for the free molecule of 1, its fully relaxed (ϕ, ψ) conformational energy map was generated with the ab initio methods. The conformer with the torsion angles ϕ,ψ = –43°, 130°, being very close to the solid-state conformers of usaturated amides, has been found among the energy-minimised structures of this molecule.
© 2004 Oldenbourg Wissenschaftsverlag GmbH
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- Molecular and crystal structure of Ac-(Z)-ΔAbu-NMe2 and Ac-DL-Abu-NMe2 as compared to those of related molecules
- J-aggregate structures in crystals of three bisazomethine dyes
- Books Received
Articles in the same Issue
- Editorial: Structure Analysis of Thin Films and Nanostructures
- High resolution X-ray diffraction of MOVPE-grown ZnO/GaN/sapphire layers
- Exact determination of Indium incorporation in (InxGa1–xN/GaN)-multiple quantum well structures by X-ray diffraction and -reflectivity and its impact on optical properties
- Annealing studies of high Ge composition Si/SiGe multilayers
- Lateral periodicity of elastic domains in MnAs/GaAs(001) epitaxial layers studied by high resolution X-ray diffraction
- X-ray reflectivity study of the influence of temperature fluctuations on the density profile of thin liquid films
- Polymeric structures at interfaces: An X-ray scattering study
- X-ray and VIS light scattering from light-induced polymer gratings
- Imaging plates – a new life for electron diffraction structure analysis
- On the superstructure of KTiO2(OH)
- Molecular and crystal structure of Ac-(Z)-ΔAbu-NMe2 and Ac-DL-Abu-NMe2 as compared to those of related molecules
- J-aggregate structures in crystals of three bisazomethine dyes
- Books Received
