I. U. Muzaddadi, A. Murugan, M. Hemamalini, M. N. Tahir, N. Raman, B. Bezbaruah, B. Ahmed, A. Manohar, A. Kulandaisamy, M. F. Hussain, T. Rajkumar
{"title":"Investigation of Oxidative Behaviour and Structural Insights of (3,4,5-Trimethoxyphenyl)Porphyrin Ni(II) Complex: Experimental and Theoretical Study","authors":"I. U. Muzaddadi, A. Murugan, M. Hemamalini, M. N. Tahir, N. Raman, B. Bezbaruah, B. Ahmed, A. Manohar, A. Kulandaisamy, M. F. Hussain, T. Rajkumar","doi":"10.1134/s0036023624601521","DOIUrl":null,"url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p><i>Meso</i> 5,10,15,20-tetrakis(3,4,5-trimethoxyphenyl)porphyrin [H<sub>2</sub>T(3,4,5-OCH<sub>3</sub>)PP] and its Ni complex [T(3,4,5-OCH<sub>3</sub>)PP Ni] (complex <b>1</b>) have been prepared. Its oxidation characteristics were examined using diverse analytical techniques, such as UV-visible spectrophotometry (UV-Vis), electron paramagnetic resonance (EPR), cyclic voltammetry (CV), and nuclear magnetic resonance (NMR) with antimony pentachloride (SbCl<sub>5</sub>) or trifluoroacetic acid (TFA). The structure of the titled compound has been confirmed by single-crystal analysis. Cyclic voltammetry study of complex <b>1</b> provides that Ni<sup>II</sup> is converted to Ni<sup>III</sup> porphyrin through π-cation radical formation which is further EPR supported by IR spectrum peaks at 1276 cm<sup>–1</sup> with the addition of SbCl<sub>5</sub>. The confirmation of formation of the π-cation radical has been established by the emergence of a novel peak at 649.5 nm in the UV-visible spectrum. This peak, indicative of oxidation, was observed at the central Ni ion, distinguishing it from the porphyrin macrocycle. Additionally, the EPR spectrum informed the formation of Ni(III) from Ni(II) porphyrin which is oxidized with SbCl<sub>5</sub> or CF<sub>3</sub>COOH (TFA) as <span>\\(d_{z}^{2}\\)</span> orbital has a single electron with high spin, <i>S</i> = 3/2 ground state in complex <b>1</b>. Crystallographic analysis and Hirshfeld surface analysis, show hydrogen bonding and molecular packing in the crystal lattice. DFT calculation and experimental HOMO–LUMO gap in solvent closely align with the theoretically determined HOMO–LUMO energy difference (0.92 eV) for complex <b>1</b>.</p>","PeriodicalId":762,"journal":{"name":"Russian Journal of Inorganic Chemistry","volume":"43 1","pages":""},"PeriodicalIF":1.8000,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Russian Journal of Inorganic Chemistry","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1134/s0036023624601521","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, INORGANIC & NUCLEAR","Score":null,"Total":0}
引用次数: 0
Abstract
Meso 5,10,15,20-tetrakis(3,4,5-trimethoxyphenyl)porphyrin [H2T(3,4,5-OCH3)PP] and its Ni complex [T(3,4,5-OCH3)PP Ni] (complex 1) have been prepared. Its oxidation characteristics were examined using diverse analytical techniques, such as UV-visible spectrophotometry (UV-Vis), electron paramagnetic resonance (EPR), cyclic voltammetry (CV), and nuclear magnetic resonance (NMR) with antimony pentachloride (SbCl5) or trifluoroacetic acid (TFA). The structure of the titled compound has been confirmed by single-crystal analysis. Cyclic voltammetry study of complex 1 provides that NiII is converted to NiIII porphyrin through π-cation radical formation which is further EPR supported by IR spectrum peaks at 1276 cm–1 with the addition of SbCl5. The confirmation of formation of the π-cation radical has been established by the emergence of a novel peak at 649.5 nm in the UV-visible spectrum. This peak, indicative of oxidation, was observed at the central Ni ion, distinguishing it from the porphyrin macrocycle. Additionally, the EPR spectrum informed the formation of Ni(III) from Ni(II) porphyrin which is oxidized with SbCl5 or CF3COOH (TFA) as \(d_{z}^{2}\) orbital has a single electron with high spin, S = 3/2 ground state in complex 1. Crystallographic analysis and Hirshfeld surface analysis, show hydrogen bonding and molecular packing in the crystal lattice. DFT calculation and experimental HOMO–LUMO gap in solvent closely align with the theoretically determined HOMO–LUMO energy difference (0.92 eV) for complex 1.
期刊介绍:
Russian Journal of Inorganic Chemistry is a monthly periodical that covers the following topics of research: the synthesis and properties of inorganic compounds, coordination compounds, physicochemical analysis of inorganic systems, theoretical inorganic chemistry, physical methods of investigation, chemistry of solutions, inorganic materials, and nanomaterials.