{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,14]],"date-time":"2025-10-14T00:42:59Z","timestamp":1760402579356,"version":"build-2065373602"},"reference-count":46,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2020,4,13]],"date-time":"2020-04-13T00:00:00Z","timestamp":1586736000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Applied Sciences"],"abstract":"<jats:p>The synthesis and characterization of a set of iron(III) complexes, viz. the mononuclear [Fe(L)3] (1) and [NHEt3][Fe(L)2(Cl)2] (2), the dinuclear methoxido-bridged [Fe(L)2(\u03bc-OMe)]2.DMF.1.5MeOH (3), and the heteronuclear Fe(III)\/Na(I) two-dimensional coordination polymer [Fe(N3)(\u03bc-L)2(\u03bc-O)1\/2(Na)(\u03bc-H2O)1\/2]n (4), are reported. Reactions of 3-amino-2-pyrazinecarboxylic acid (HL) with iron(III) chloride under different reaction conditions were studied, and the obtained compounds were characterized by elemental analysis, Fourier Transform Infrared (FT-IR) spectroscopy, and X-ray single-crystal diffraction. Compound 1 is a neutral mononuclear complex, whereas 2 is mono-anionic with its charge being neutralized by triethylammonium cation. Compounds 3 and 4 display a di-methoxido-bridged dinuclear complex and a two-dimensional heterometallic Fe(III)\/Na(I) polynuclear coordination polymer, respectively. Compounds 3 and 4 are the first examples of methoxido- and oxido-bridged iron(III) complexes, respectively, with 3-amino-2-pyrazinecarboxylate ligands. The electrochemical study of these compounds reveals a facile single-electron reversible Fe(III)-to-Fe(II) reduction at a positive potential of 0.08V vs. saturated calomel electrode (SCE), which is in line with their ability to act as efficient oxidants and heterogeneous catalysts for the solvent-free microwave-assisted peroxidative oxidation (with tert-butyl hydroperoxide) of cyclohexanol to cyclohexanone (almost quantitative yields after 1 h). Moreover, the catalysts are easily recovered and reused for five consecutive cycles, maintaining a high activity and selectivity.<\/jats:p>","DOI":"10.3390\/app10082692","type":"journal-article","created":{"date-parts":[[2020,4,14]],"date-time":"2020-04-14T03:10:01Z","timestamp":1586833801000},"page":"2692","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Synthesis, Structures, Electrochemistry, and Catalytic Activity towards Cyclohexanol Oxidation of Mono-, Di-, and Polynuclear Iron(III) Complexes with 3-Amino-2-Pyrazinecarboxylate"],"prefix":"10.3390","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3047-2204","authenticated-orcid":false,"given":"Anirban","family":"Karmakar","sequence":"first","affiliation":[{"name":"Centro de Qu\u00edmica Estrutural, Instituto Superior T\u00e9cnico, Universidade de Lisboa, Av. Rovisco Pais, 1049\u2013001 Lisbon, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5403-9352","authenticated-orcid":false,"given":"Lu\u00edsa","family":"M.D.R.S. Martins","sequence":"additional","affiliation":[{"name":"Centro de Qu\u00edmica Estrutural, Instituto Superior T\u00e9cnico, Universidade de Lisboa, Av. Rovisco Pais, 1049\u2013001 Lisbon, Portugal"}]},{"given":"Yuliya","family":"Yahorava","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Technology of Electrochemical Production and Electronic Engineering Materials, Belarusian State Technological University, 13a Sverdlova str., 220006 Minsk, Belarus"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4836-2409","authenticated-orcid":false,"given":"M. F\u00e1tima","family":"C. Guedes da Silva","sequence":"additional","affiliation":[{"name":"Centro de Qu\u00edmica Estrutural, Instituto Superior T\u00e9cnico, Universidade de Lisboa, Av. Rovisco Pais, 1049\u2013001 Lisbon, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5403-9352","authenticated-orcid":false,"given":"Armando","family":"J. L. Pombeiro","sequence":"additional","affiliation":[{"name":"Centro de Qu\u00edmica Estrutural, Instituto Superior T\u00e9cnico, Universidade de Lisboa, Av. Rovisco Pais, 1049\u2013001 Lisbon, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2020,4,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2006","DOI":"10.1021\/ic950801g","article-title":"(\u03bc-Oxo)diiron Complexes of Gated Glyoximes. Structural Changes Accompanying Ligation Trans to the Oxo Bridge","volume":"35","author":"Vernik","year":"1996","journal-title":"Inorg. Chem."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"759","DOI":"10.1021\/cr00027a011","article-title":"Reactions of Non-Heme Iron(II) Centers with Dioxygen in Biology and Chemistry","volume":"94","author":"Feig","year":"1994","journal-title":"Chem. 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