| 1. |
- Cao, Guanyue, et al.
(författare)
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Porphyrindiene-Based Tandem Diels-Alder Reaction for Preparing Low-Symmetry pi-Extended Porphyrins with Push-Pull Skeletons
- 2022
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Ingår i: Journal of Organic Chemistry. - : AMER CHEMICAL SOC. - 0022-3263 .- 1520-6904. ; 87:14, s. 9001-9010
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Tidskriftsartikel (refereegranskat)abstract
- Tandem Diels-Alder reactions of masked porphyrindienes (i.e., sulfolenoporphyrins) with benzoquinones and stilbenes, followed by aromatization, have been developed to load porphyrin with mixed annulation units (i.e., terphenyl and naphthoquinone), furnishing the low-symmetry pi-extended porphyrins (DxAy) with push-pull skeletons. All low-symmetrical chromophores display panchromatic absorption spectra, which look like a spectral combination of symmetrical congeners (D4/A4) in a certain ratio. Among them, tD2A2 with trans-arrangement of push/pull units possesses the largest maximum centered at 766 nm with the onset around 900 nm. The fusion of the electron-deficient naphthoquinone moiety on the porphyrin core results in the approximately quantitative regulation of the E-ox1 and HOMOs (i.e., 0.10-0.13 V increase for the E-ox1 and 0.14-0.16 eV decrease for the HOMOs per naphthoquinone unit). In brief, this work provides a new way to construct low-symmetry pi-extended porphyrins with tunable properties resorting to the ratios and locations of the annulated push-pull units.
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| 2. |
- Chen, Yingying, et al.
(författare)
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Fluorenyl Indoline as an Efficient Electron Donor for Concerted Companion Dyes: Enhanced Light-Harvesting and Photocurrent
- 2021
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Ingår i: ACS Applied Materials and Interfaces. - : AMER CHEMICAL SOC. - 1944-8244 .- 1944-8252. ; 13:42, s. 49828-49839
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Tidskriftsartikel (refereegranskat)abstract
- Concerted companion dyes (CC dyes) like XW61 have been demonstrated to be an effective platform for developing efficient DSSCs. However, the moderated phenothiazine-based electron donor in XW61 results in unsatisfactory J(sc). To address this problem, a stronger fluorenyl indoline-based electron donor has been used to construct porphyrin dye XW68 and organic dyes Y1-Y2. The stronger electron-donating character of the fluorenyl indoline unit leads to an enhanced J(sc) value (20.48 mA.cm(-2)) for the individual dye XW68. On this basis, CC dyes XW69-XW70-C8 have been designed and synthesized by combining the frameworks of Y1 and Y2 with XW68. The complementary absorption characters of the porphyrin and the organic dye moieties lead to panchromatic absorption with a strong light-harvesting capability from 350 to 700 nm and the onset wavelength extended to ca. 840 nm in the IPCE curves. As a result, excellent J(sc) values have been achieved (>22 mA.cm(-2)). In addition to the advantages of high J(sc), bulky octyl groups have been introduced into the donor of XW70-C8 to reduce dye aggregation and suppress charge recombination. Finally, a highest PCE of 11.1% with a satisfactory J(sc) (22.25 mA.cm(-2)) and an enhanced V-oc (750 mV) has been achieved upon coadsorption of XW70-C8 with CDCA. In addition, the CC dye XW70-C8-based solar cells exhibit excellent long-term photostability. These results provide an effective method for rationally improving the photovoltaic behavior, especially the J(sc) of CC dyes, by introducing strong electron donor moieties with suitable substituents.
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| 3. |
- Du, Yu, et al.
(författare)
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N-Confused Hexapyrrolic Phlorinoid with NIR Absorption : Synthesis, Fusion, Oxidation, and Copper(II) Coordination
- 2020
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Ingår i: Organic Letters. - : American Chemical Society (ACS). - 1523-7060 .- 1523-7052. ; 22:24, s. 9648-9652
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Tidskriftsartikel (refereegranskat)abstract
- An N-confused hexapyrrolic phlorinoid 1 and its isomer N-fused hexapyrrolic phlorinoid 2 were synthesized through [4 + 2] condensation. Both 1 and 2 can be readily transformed into N-confused hexapyrrolic phlorinone 3 under aerobic conditions. Coordination of 1 with Cu(acac)(2) afforded two different mono-Cu(II) complexes 4 and 5 with CNNN and ONNN coordination environments, respectively. The NIR absorption bands can be effectively modulated up to 1265 nm through the oxidation, fusion, and metalation reactions.
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| 4. |
- Fu, Yating, et al.
(författare)
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Rational Synthesis of 5,5,5-Tricyclic Fused Thia-heptaphyrin (1.1.1.1.1.1.0) From a Helical Oligopyrrin Hybrid
- 2020
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Ingår i: Chemistry - An Asian Journal. - : WILEY-V C H VERLAG GMBH. - 1861-4728 .- 1861-471X. ; 15:8, s. 1285-1289
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Tidskriftsartikel (refereegranskat)abstract
- Oxidation of a thiophene-hexapyrrane hybrid S-P-6 afforded a stable conjugated open-chain thiaheptapyrrolic helix 1 with the terminal thiophene and confused pyrrole units lying at a long distance that is adverse for further cyclization. Chelation of 1 with copper(II) ion afforded 1-Cu, which exhibits more distant terminal units. Interestingly, further oxidation of 1 triggered an intramolecular C-N fusion reaction to afford a unique 5,5,5-tricyclic fused linear thiaheptapyrrin 2, with the two terminals positioned in proximity, which favors the oxidative ring-closure reaction to give a unique 5,5,5-tricyclic fused thiaheptaphyrin (1.1.1.1.1.1.0) 3 under air. The inner-fusion strategy for positioning the reactive sites in proximity to promote oxidative cyclization offers a new approach for constructing large porphyrinoids through conjugated oligopyrrins without the assistance of metal ions.
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| 5. |
- Gao, Shimin, et al.
(författare)
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Stable thiophene-embedded N-confused homoporphyrins : Partial conjugation, fusion and fluoride binding
- 2021
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Ingår i: Dyes and pigments. - : Elsevier. - 0143-7208 .- 1873-3743. ; 194
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Tidskriftsartikel (refereegranskat)abstract
- In the past decades, porphyrin analogues have attracted increasing attention in light of their unique properties and potential applications in various areas. In this work, novel nonconjugated thiophene-embedded N-confused homoporphyrins 1 and 2 as well as a fully-conjugated N-fused homoporphyrin 3 have been prepared through acid-catalyzed condensation reactions followed by oxidation. Both 1 and 2 comprise two meso-sp3-carbon atoms. However, they are insensitive to the air or common oxidants. Single crystal X-ray diffraction analysis reveals that 2 adopts a highly distorted boat-like conformation, with the NH moieties of two pyrrolic units pointing outwards and an O atom attached to the alpha position of the N-confused pyrrole unit. As a result, hydrogen-bonded dimers are formed through the intermolecular hydrogen bonds between the lactam-like moieties. In contrast to the highly distorted structure of 2, N-fused homoporphyrin 3 contains a unique 5,5,5-tricyclic fused ring, and thus demonstrates a relatively coplanar conformation except one inverted pyrrole unit. Because of the different structural characters, 3 exhibits F- binding behavior distinct from that of 1 and 2.
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| 6. |
- Gao, Shimin, et al.
(författare)
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Syntheses of thiophene appended N-confused phlorin isomers
- 2021
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Ingår i: Journal of Porphyrins and Phthalocyanines. - : World Scientific Pub Co Pte Ltd. - 1088-4246 .- 1099-1409. ; 25:10N12, s. 997-1003
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Tidskriftsartikel (refereegranskat)abstract
- A doubly confused thiapentapyrrane NSP-5 was synthesized by acid-catalysed condensation. Subsequent oxidation with DDQ did not afford the expected thiasapphyrin-like product. Instead, two tetrapyrrolic macrocycles, i.e. neo-N-confused phlorin (1) and N-confused phlorin-II (2) were obtained in the yields of 14% and 18%, respectively. The compounds were characterized by NMR, HRMS, and X-ray diffraction analyses. Single crystal structures clearly reveal that the thienyl units are not embedded into the macrocycles, but appended as meso-substituents, and the C-meso-N and C-meso-C-beta cyclization modes can be clearly revealed by the crystal structures of 1 and 2, respectively. The observation that the thienyl unit is not involved in oxidative cyclization may be related to the relatively low reactivity of the thiophene moiety compared with the more electron-rich pyrrole unit. These results indicate that oxidative cyclization of linear thiaoligopyrranes containing terminal thiophene units may be developed as an effective approach for synthesizing nonconjugated macrocycles like phlorin analogues.
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| 7. |
- Gao, Shimin, et al.
(författare)
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Synthesis, characterization, and spectroscopic properties of 2-(3,5,6-trichloro-1,4-benzoquinon-2-yl)-neo-fused hexaphyrin
- 2021
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Ingår i: Bulletin of the Korean Chemical Society (Print). - : John Wiley & Sons. - 0253-2964 .- 1229-5949. ; 42:12, s. 1569-1573
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Tidskriftsartikel (refereegranskat)abstract
- In this work, a novel compound 2-(3,5,6-trichloro-1,4-benzoquinon-2-yl)-neo-fused hexaphyrin has been prepared from tetrachloroquinone and neo-fused hexaphyrin through a substitution reaction. The chemical structure of the compound has been characterized by nuclear magnetic resonance (NMR), high-resolution mass spectrum, UV-Vis spectrum, and X-ray diffraction. The crystal structure reveals that the quinonyl unit is almost coplanar with the adjacent N-confused pyrrole unit. Because of the cooperative effect of extended conjugation and the intramolecular charge transfer effect related to the strong electron-withdrawing character of the quinonyl unit, the absorption of 2 is dramatically extended to ca. 1280 nm.
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| 8. |
- He, Yixing, et al.
(författare)
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Chain Length Modulated Dimerization and Cyclization of Terminal Thienyl-Blocked Oligopyrranes
- 2022
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Ingår i: Organic Letters. - : AMER CHEMICAL SOC. - 1523-7060 .- 1523-7052. ; 24:29, s. 5428-5432
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Tidskriftsartikel (refereegranskat)abstract
- Oxidation of thienyl-blocked bilane and pentapyrrane afforded chain length dependent products of the symmetric dimer D1 and the thienyloligopyrrin-appended pentaphyrin analogue P2, respectively, with the latter formed by simultaneous dimerization and cyclization. Coordination of D1 and P2 with Cu(II) afforded di-and monometallic complexes D1-Cu2 and P2 -Cu, respectively. These compounds exhibit distinct NIR absorption, with the absorption tail of D1-Cu2 extended to ca. 1900 nm despite its smaller conjugation framework than that of P2 -Cu.
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| 9. |
- Huang, Yanping, et al.
(författare)
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Syntheses and characterization of dithienyl-blocked hexapyrrin and its mononuclear complexes
- 2023
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Ingår i: Journal of Porphyrins and Phthalocyanines. - : World Scientific. - 1088-4246 .- 1099-1409. ; 27:07N10, s. 1089-1096
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Tidskriftsartikel (refereegranskat)abstract
- With the purpose to develop long chain-conjugated oligopyrrin-like compounds and their metal complexes, and thus achieve tunable near-infrared absorption, a dithienyl-blocked hexapyrrane S-2-P-6 was synthesized by acid-catalyzed [2+4+2] condensation, followed by oxidation with DDQ to afford dithiaoctapyrrin 1, and its mononuclear metal complexes 1-Cu and 1-Zn were synthesized by treating 1 with Cu(II) and Zn(II) acetates. All the compounds were systematically characterized by NMR/EPR, and HRMS. The crystal structures revealed that 1 adopts a double hook-like conformation. Whereas, both complexes 1-Cu and 1-Zn adopt spiral-hook hybrid conformations, showing smaller interplanar angles between the rings within the spiral part, compared with those in the hook-like counterpart of molecule 1, which is favorable for red-shifting the absorption. As expected, the absorption band edges for complexes 1-Cu and 1-Zn are red-shifted to ca. 1560 nm, compared with that of 1260 nm observed for 1.
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| 10. |
- Huang, Yanping, et al.
(författare)
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Syntheses and coordination of linear and macrocyclic pentapyrroles possessing a fused moiety : Confusion modulated structural diversity
- 2024
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Ingår i: Dyes and pigments. - : Elsevier. - 0143-7208 .- 1873-3743. ; 223
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Tidskriftsartikel (refereegranskat)abstract
- Porphyrinoids have attracted wide interest because of their vital roles in biological processes and fascinating structural and functional characters. In this work, a doubly N-confused pentapyrrane precursor N2C–P5 has been synthesized with terminal pyrrole ring A and middle pyrrole C incorporated in the N-confused mode. On this basis, pentapyrrin 1 and sapphyrin 2 have been synthesized by oxidizing N2C–P5 with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). Both 1 and 2 possess a [5.5.5]-tricyclic fused ring involving pyrrole B and the neighboring confused pyrrole C. Meanwhile, the formation of 2 involves ring closure between the terminal rings A and E. Notably, 2 exists as a diradical showing a half-field signal in the electron paramagnetic resonance (EPR) spectrum and a singlet ground state with a negative singlet-triplet energy gap of −0.50 kcal/mol. Excellent thermal stability has been observed for 2, which may be related to its large π-conjugated framework involving the fused structure. On this basis, 1 and 2 were treated with Cu(acac)2 to afford Cu(II) complexes 3 and 4, respectively. As a result, an acetylacetonyl moiety is attached at the terminal pyrrole ring E to afford an NNNO coordination environment for complex 3, and the sapphyrin macrocycle of 2 has been cleaved between rings A and B to afford a fused pentapyrrin ligand, furnishing an NNNN coordination environment for complex 4, in which a pentafluorophenyl-ketal group generated during the ring cleavage reaction is attached to ring A, and it can be hydrolyzed to the corresponding pentafluorobenzoyl substituent to afford complex 5. Compared with free bases 1 and 2, complexes 3−5 show more intense low-energy near-infrared (NIR) absorption bands at ca. 791, 926 and 907 nm, respectively. This work provides an effective approach for the syntheses of linear and macrocyclic oligopyrroles with intriguing structures and properties by oxidizing oligopyrranes with precisely designed numbers and positions of N-confused pyrroles.
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