Central-to-Helical-to-Axial Chirality Transfer in Chiroptical Sensing with Ferrocene Chromophore
The effect of attaching the achiral, cyclic 1-aminocyclohexanecarboxylic acid (Ac6c) directly to the aminoferrocene unit (Ac6c−NH−Fc) appears to be a promising route for the development of a new chiroptical sensor based on a ferrocene chromophore. Three new compounds (Boc−AA−Ac6c−NH−Fc; AA = L-Ala,...
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MDPI AG
2023-05-01
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| Series: | Inorganics |
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| Online Access: | https://www.mdpi.com/2304-6740/11/6/225 |
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| author | Marko Nuskol Petar Šutalo Monika Kovačević Ivan Kodrin Mojca Čakić Semenčić |
| author_facet | Marko Nuskol Petar Šutalo Monika Kovačević Ivan Kodrin Mojca Čakić Semenčić |
| author_sort | Marko Nuskol |
| collection | DOAJ |
| description | The effect of attaching the achiral, cyclic 1-aminocyclohexanecarboxylic acid (Ac6c) directly to the aminoferrocene unit (Ac6c−NH−Fc) appears to be a promising route for the development of a new chiroptical sensor based on a ferrocene chromophore. Three new compounds (Boc−AA−Ac6c−NH−Fc; AA = L-Ala, L-Val, L-Phe) were synthesized, spectroscopically characterized (IR, NMR, CD), and conformationally analyzed (DFT). The chiral information was transferred from the L-amino acid to the ferrocene chromophore by the predominant formation of <i>P</i>-helical structures with ten-membered hydrogen-bonded rings (β-turns). The perturbation of the ferrocene chromophore and the appearance of the negative CD signal near 470 nm originates from a relative orientation of the directly linked amide and cyclopentadienyl planes, described by the dihedral angle <i>χ</i>. The sterically demanding Ac6c amino acid makes <i>trans</i>-like configurations more favorable and thus restricts the dihedral angle <i>χ</i>, which then leads to the appearance of the negative peak near 470 nm in the CD curve. |
| first_indexed | 2024-03-11T02:19:04Z |
| format | Article |
| id | doaj.art-11fde3f8a7774afc9a34d7eeaf63a773 |
| institution | Directory Open Access Journal |
| issn | 2304-6740 |
| language | English |
| last_indexed | 2024-03-11T02:19:04Z |
| publishDate | 2023-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Inorganics |
| spelling | doaj.art-11fde3f8a7774afc9a34d7eeaf63a7732023-11-18T10:55:01ZengMDPI AGInorganics2304-67402023-05-0111622510.3390/inorganics11060225Central-to-Helical-to-Axial Chirality Transfer in Chiroptical Sensing with Ferrocene ChromophoreMarko Nuskol0Petar Šutalo1Monika Kovačević2Ivan Kodrin3Mojca Čakić Semenčić4Department of Chemistry and Biochemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, CroatiaDepartment of Chemistry Faculty of Science, University of Zagreb, Horvatovac 102a, 10000 Zagreb, CroatiaDepartment of Chemistry and Biochemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, CroatiaDepartment of Chemistry Faculty of Science, University of Zagreb, Horvatovac 102a, 10000 Zagreb, CroatiaDepartment of Chemistry and Biochemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, CroatiaThe effect of attaching the achiral, cyclic 1-aminocyclohexanecarboxylic acid (Ac6c) directly to the aminoferrocene unit (Ac6c−NH−Fc) appears to be a promising route for the development of a new chiroptical sensor based on a ferrocene chromophore. Three new compounds (Boc−AA−Ac6c−NH−Fc; AA = L-Ala, L-Val, L-Phe) were synthesized, spectroscopically characterized (IR, NMR, CD), and conformationally analyzed (DFT). The chiral information was transferred from the L-amino acid to the ferrocene chromophore by the predominant formation of <i>P</i>-helical structures with ten-membered hydrogen-bonded rings (β-turns). The perturbation of the ferrocene chromophore and the appearance of the negative CD signal near 470 nm originates from a relative orientation of the directly linked amide and cyclopentadienyl planes, described by the dihedral angle <i>χ</i>. The sterically demanding Ac6c amino acid makes <i>trans</i>-like configurations more favorable and thus restricts the dihedral angle <i>χ</i>, which then leads to the appearance of the negative peak near 470 nm in the CD curve.https://www.mdpi.com/2304-6740/11/6/225circular dichroism (CD)density functional theory (DFT)conformational analysisferrocene peptideschirality |
| spellingShingle | Marko Nuskol Petar Šutalo Monika Kovačević Ivan Kodrin Mojca Čakić Semenčić Central-to-Helical-to-Axial Chirality Transfer in Chiroptical Sensing with Ferrocene Chromophore Inorganics circular dichroism (CD) density functional theory (DFT) conformational analysis ferrocene peptides chirality |
| title | Central-to-Helical-to-Axial Chirality Transfer in Chiroptical Sensing with Ferrocene Chromophore |
| title_full | Central-to-Helical-to-Axial Chirality Transfer in Chiroptical Sensing with Ferrocene Chromophore |
| title_fullStr | Central-to-Helical-to-Axial Chirality Transfer in Chiroptical Sensing with Ferrocene Chromophore |
| title_full_unstemmed | Central-to-Helical-to-Axial Chirality Transfer in Chiroptical Sensing with Ferrocene Chromophore |
| title_short | Central-to-Helical-to-Axial Chirality Transfer in Chiroptical Sensing with Ferrocene Chromophore |
| title_sort | central to helical to axial chirality transfer in chiroptical sensing with ferrocene chromophore |
| topic | circular dichroism (CD) density functional theory (DFT) conformational analysis ferrocene peptides chirality |
| url | https://www.mdpi.com/2304-6740/11/6/225 |
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