caa a22 4500 378939653 CHVBK 20180305123649.0 cr unu---uuuuu 161128e20040401xx s 000 0 eng 10.1524/zkri.219.4.231.30447 doi (NATIONALLICENCE)gruyter-10.1524/zkri.219.4.231.30447 Molecular and crystal structure of Ac-(Z)-ΔAbu-NMe2 and Ac-DL-Abu-NMe2 as compared to those of related molecules [Elektronische Daten] [Dawid Siodłak, Malgorzata A. Broda, Barbara Rzeszotarska, Edyta Kołodziejczyk, Anna E. Kozioł] 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 Crystallography nationallicence Inorganic chemistry nationallicence Organic chemistry nationallicence Siodłak Dawid aut Broda Malgorzata A. aut Rzeszotarska Barbara aut Kołodziejczyk Edyta aut Kozioł Anna E. aut Zeitschrift für Kristallographie - Crystalline Materials De Gruyter Oldenbourg 219/4(2004-04-01), 231-238 2194-4946 219:4<231 2004 219 zkri https://doi.org/10.1524/zkri.219.4.231.30447 text/html Onlinezugriff via DOI 1 research article jats NATIONALLICENCE 856 40 https://doi.org/10.1524/zkri.219.4.231.30447 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Siodłak Dawid aut NATIONALLICENCE 700 1- Broda Malgorzata A. aut NATIONALLICENCE 700 1- Rzeszotarska Barbara aut NATIONALLICENCE 700 1- Kołodziejczyk Edyta aut NATIONALLICENCE 700 1- Kozioł Anna E. aut NATIONALLICENCE 773 0- Zeitschrift für Kristallographie - Crystalline Materials De Gruyter Oldenbourg 219/4(2004-04-01), 231-238 2194-4946 219:4<231 2004 219 zkri CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-gruyter