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Nevonen DE, Atoyebi AO, Luciano MP, Brückner C, Nemykin VN. Electronic Structures of an Annulated meso-Tetraphenylchlorin and a Related Chlorin Analogue Incorporating an 8-Membered Ring through MCD Spectroscopy and DFT Calculations. J Phys Chem A 2024; 128:4823-4829. [PMID: 38857383 DOI: 10.1021/acs.jpca.4c02803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2024]
Abstract
Herein, we compare the electronic structures of the metal-free and nickel(II) derivatives of an annulated meso-tetraphenyldihydroxychlorin with those of the (metallo)chlorin analogues derived by pyrroline β,β'-ring cleavage of the annulated (metallo)chlorins. These (metallo)chlorin analogues incorporate 8-membered heterocycles in place of the pyrroline, carry oxo-functionalities on the former pyrroline β-carbon atoms, and were previously shown to possess drastically ruffled (twisted) nonplanar conformations. The magnetic circular dichroism spectra of all chromophores investigated feature chlorin-like UV-vis spectra and correspondingly reversed (positive-to-negative in ascending energy) sign sequences in the Q-band region, indicative of ΔHOMO < ΔLUMO relationships. Density functional theory (DFT) calculations indicate that the HOMOs in all compounds are a1u-type molecular orbitals (in traditional for the porphyrin spectroscopy D4h point group). Time-dependent DFT calculations correlate well with the experimental spectra and indicate that Gouterman's four-orbital model can be applied to these chromophores. This work highlights to which degree synthetic chlorin analogues can deviate from the structural parameters of natural chlorins without losing their electronic chlorin characteristics.
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Affiliation(s)
- Dustin E Nevonen
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Adewole O Atoyebi
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Michael P Luciano
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Christian Brückner
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Victor N Nemykin
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
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Zhuang W, Xiao F, Chen Y, Zhang X, Huang Q. Cascade Electrochemical Aerobic Oxygenation of 2-Substituted Indoles and Electrochemical [5 + 3] Annulation with Amidines: Access to Eight-Membered Benzo[1,3,5]triazocin-6(5 H)-ones. J Org Chem 2024; 89:4673-4683. [PMID: 38478890 DOI: 10.1021/acs.joc.3c02931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2024]
Abstract
The cascade electrochemical C3-selective aerobic oxygenation of 2-substituted indoles and electrochemical [5 + 3] annulation with amidines through an undivided cell galvanostatic method employing molecular oxygen and "electricity" as green oxidants was developed. This protocol provides an efficient and direct approach to eight-membered benzo[1,3,5]triazocin-6(5H)-ones. Mechanistic studies suggested that two subsequent electrochemical processes both proceeded through radical pathways.
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Affiliation(s)
- Weihui Zhuang
- Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, College of Chemistry & Materials Science, Fujian Normal University, Fuzhou, Fujian 350007, PR China
| | - Fengyi Xiao
- Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, College of Chemistry & Materials Science, Fujian Normal University, Fuzhou, Fujian 350007, PR China
| | - Yumei Chen
- Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, College of Chemistry & Materials Science, Fujian Normal University, Fuzhou, Fujian 350007, PR China
| | - Xiaofeng Zhang
- Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, College of Chemistry & Materials Science, Fujian Normal University, Fuzhou, Fujian 350007, PR China
| | - Qiufeng Huang
- Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, College of Chemistry & Materials Science, Fujian Normal University, Fuzhou, Fujian 350007, PR China
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Thuita DW, Brückner C. Metal Complexes of Porphyrinoids Containing Nonpyrrolic Heterocycles. Chem Rev 2022; 122:7990-8052. [PMID: 35302354 DOI: 10.1021/acs.chemrev.1c00694] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The replacement of one or more pyrrolic building block(s) of a porphyrin by a nonpyrrolic heterocycle leads to the formation of so-called pyrrole-modified porphyrins (PMPs), porphyrinoids of broad structural variability. The wide range of coordination environments (type, number, charge, and architecture of the donor atoms) that the pyrrole-modified frameworks provide to the central metal ions, the frequent presence of donor atoms at their periphery, and their often observed nonplanarity or conformational flexibility distinguish the complexes of the PMPs clearly from those of the traditional square-planar, dianionic, N4-coordinating (hydro)porphyrins. Their different coordination properties suggest their utilization in areas beyond which regular metalloporphyrins are suitable. Following a general introduction to the synthetic methodologies available to generate pyrrole-modified porphyrins, their general structure, history, coordination chemistry, and optical properties, this Review highlights the chemical, electronic (optical), and structural differences of specific classes of metalloporphyrinoids containing nonpyrrolic heterocycles. The focus is on macrocycles with similar "tetrapyrrolic" architectures as porphyrins, thusly excluding the majority of expanded porphyrins. We highlight the relevance and application of these metal complexes in biological and technical fields as chemosensors, catalysts, photochemotherapeutics, or imaging agents. This Review provides an introduction to the field of metallo-PMPs as well as a comprehensive snapshot of the current state of the art of their synthesis, structures, and properties. It also aims to provide encouragement for the further study of these intriguing and structurally versatile metalloporphyrinoids.
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Affiliation(s)
- Damaris Waiyigo Thuita
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060, United States
| | - Christian Brückner
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060, United States
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Luciano MP, Atoyebi AO, Tardie W, Zeller M, Brückner C. Pyrrole-Modified Porphyrins Containing Eight-Membered Heterocycles Using a Reversal of the "Breaking and Mending" Strategy. J Org Chem 2020; 85:15273-15286. [PMID: 33174754 DOI: 10.1021/acs.joc.0c02108] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The conversion of meso-aryl-porphyrins/chlorins to porphyrinoids containing nonpyrrolic heterocycles (so-called pyrrole-modified porphyrins, PMPs) along an approach we dubbed "the breaking and mending of porphyrins" is well known. However, examples are limited to the synthesis of PMPs containing up to six-membered heterocycles; the syntheses of larger rings failed. We report here hitherto unavailable eight-membered chlorin-type PMPs using an inverted "mending and breaking" approach. All examples are based on the addition of N,N'-dimethylurea derivatives to a meso-phenyl-β,β'-dioxoporphyrin, followed by oxidative cleavage of the intermediate diol adduct. We correlate the extremely nonplanar solid-state structures of three crystallographically characterized PMPs containing an eight-membered ring with their solution-state optical properties. The first examples of bis-modified, bacteriochlorin-type PMPs containing either two eight-membered rings or an eight-membered ring and an imidazolone ring are also detailed. Using other N,N'-nucleophiles failed to either generate chlorins containing a β,β'-dihydroxypyrroline, a prerequisite for the "breaking step," or the cleavage of those substrates that did generate a diol underwent subsequent reactions that thwarted the generation of the desired PMPs. This contribution adds novel PMPs containing eight-membered rings, highlights the effects these derivatizations have on the macrocycle conformation, and how that affects their optical properties.
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Affiliation(s)
- Michael P Luciano
- Department of Chemistry, University of Connecticut, Unit 3060, Storrs, Connecticut 06269-3060, United States
| | - Adewole O Atoyebi
- Department of Chemistry, University of Connecticut, Unit 3060, Storrs, Connecticut 06269-3060, United States
| | - Weston Tardie
- Department of Chemistry, University of Connecticut, Unit 3060, Storrs, Connecticut 06269-3060, United States
| | - Matthias Zeller
- Department of Chemistry, Purdue University, 101 Wetherill Hall, 560 Oval Drive, West Lafayette, Indiana 47907-2084, United States
| | - Christian Brückner
- Department of Chemistry, University of Connecticut, Unit 3060, Storrs, Connecticut 06269-3060, United States
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Luciano MP, Akhigbe J, Ding J, Thuita D, Hamchand R, Zeller M, Brückner C. An Alternate Route of Transforming meso-Tetraarylporphyrins to Porpholactams, and Their Conversion to Amine-Functionalized Imidazoloporphyrins. J Org Chem 2018; 83:9619-9630. [DOI: 10.1021/acs.joc.8b00790] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Michael P. Luciano
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060, United States
| | - Joshua Akhigbe
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060, United States
| | - Jiaming Ding
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060, United States
| | - Damaris Thuita
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060, United States
| | - Randy Hamchand
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060, United States
| | - Matthias Zeller
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084, United States
| | - Christian Brückner
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060, United States
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Yoshida K, Osuka A. Pyrrole-Modified Subporphyrins Bearing a Sulfur-Containing Heterocyclic Unit. Helv Chim Acta 2018. [DOI: 10.1002/hlca.201800025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Kota Yoshida
- Department of Chemistry; Graduate School of Science; Kyoto University; Sakyo-ku Kyoto 606-8502 Japan
| | - Atsuhiro Osuka
- Department of Chemistry; Graduate School of Science; Kyoto University; Sakyo-ku Kyoto 606-8502 Japan
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Li R, Zeller M, Brückner C. Surprising Outcomes of Classic Ring‐Expansion Conditions Applied to Octaethyloxochlorin, 1. Baeyer–Villiger‐Oxidation Conditions. European J Org Chem 2017. [DOI: 10.1002/ejoc.201601422] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Ruoshi Li
- Department of Chemistry University of Connecticut Storrs 06368‐3060 CT USA
| | - Matthias Zeller
- Department of Chemistry Youngstown State University One University Plaza 44555‐3663 Youngstown OH USA
| | - Christian Brückner
- Department of Chemistry University of Connecticut Storrs 06368‐3060 CT USA
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Guberman-Pfeffer MJ, Greco JA, Samankumara LP, Zeller M, Birge RR, Gascón JA, Brückner C. Bacteriochlorins with a Twist: Discovery of a Unique Mechanism to Red-Shift the Optical Spectra of Bacteriochlorins. J Am Chem Soc 2016; 139:548-560. [DOI: 10.1021/jacs.6b12419] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
| | - Jordan A. Greco
- Department
of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060, United States
| | - Lalith P. Samankumara
- Department
of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060, United States
| | - Matthias Zeller
- Department
of Chemistry, Youngstown State University, One University Plaza, Youngstown, Ohio 44555-3663, United States
| | - Robert R. Birge
- Department
of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060, United States
- Department
of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269-3125, United States
| | - José A. Gascón
- Department
of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060, United States
| | - Christian Brückner
- Department
of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060, United States
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