Naslov
Conformational analysis of heteroannularly substituted ferrocene oligoamides

Autori
Lapić, Jasmina ; Siebler, Daniel ; Heinze, Katja ; Rapić, Vladimir

Izvornik
European Journal of Inorganic Chemistry (1434-1948) 2007 (2007), 14; 2014-2024

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Conformation analysis; Density functional calculations; Hydrogen bonds; Metallocenes; Molecular modelling

Sažetak
The main conformer of symmetrical conjugates of ferrocene-1, 1’ -dicarboxylic acid with natural amino acids – Fn(CO-AA1-2-OMe)2 (type I, Fn = ferrocene-1, 1'-diyl, AA = L-alpha-amino acid) is supported by two hydrogen bonds between the podand peptide chains. In order to compare intramolecular hydrogen bond patterns of type I conjugates with related asymmetrically substituted derivatives type II (MeNHCO-Fn-CO-AA-OMe) and type III conjugates (MeNHCO-Fn-CO-AA-NHMe) were prepared in moderate to good yields in a few steps starting from 1’ -(methoxycarbonyl)ferrocene-1-carboxylic acid using the HOBt/EDC method (AA = Gly, Ala, Val). 1H NMR variation ratio analysis suggests that increasing the steric demand of the amino acid side chains favours conformations with hydrogen-bonded FnCONHMe groups. CD spectroscopy of chiral derivatives reveals that (P)-helical conformations predominate in solution. All the experimental findings are in accordance with DFT calculations.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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