RESUMEN
Hydrogen peroxide (H2O2) production driven by solar energy has received enormous attention due to its high efficiency, low cost, and environmental friendliness characteristics. Searching for new photocatalytic materials for H2O2 production is one of the most important targets. In this work, a new three-dimensional (3D) uranyl-organic framework material was constructed with mixed ligands via a solvothermal reaction and used for photocatalytic H2O2 production. The mixed ligand strategy not only benefits the construction of a 3D uranyl-organic framework but also introduces strong photon absorption groups into the framework. The thiophene and pyridine rings in the framework enhance photon absorption and carrier transfer. In addition, with the assistance of the hydrogen abstraction reaction of uranyl centers, the H2O2 production rate reaches 345 µmol h-1 g-1. This study provides a new blueprint for exploring the artificial photosynthesis of H2O2 through uranium-based metal-organic frameworks.
RESUMEN
5,18-Dimesitylorangarin and its BF2 complex were synthesized by double SNAr reaction of 3,5-dibromo-BODIPY with 2-pyrrolydipyrrin as the first examples of meso-aryl-substituted orangarin. These orangarins, delineated as [20]pentaphyrin(1.0.1.0.0), are strongly antiaromatic but rather stable. The free base orangarin was coupled by oxidation with MnO2 to give a 11,11'-linked dimer, a cyclooctatetraene(COT)-centered trimer, and a spiro-trimer. Fused COT-centered 3H-orangarin dimer was oxidized to the corresponding 2H-orangarin dimer, which was further coupled to give a triply COT-centered 2H-orangarin tetramer. 3H-Orangarin oligomers are all antiaromatic as evinced by extremely low-field-shifted 1Hâ NMR signals of the inner NH and ill-defined absorption spectra with broad tails. In contrast, COT-centered 2H-orangarin dimer and tetramer show moderately low-field-shifted NH signals and intense NIR absorbance over 900â nm, suggesting effective π-conjugation through the COT bridge and almost non-antiaromatic character. These orangarin oligomers exhibit many reversible redox potentials owing to the intramolecular electronic interactions. Regardless of the different aromatic characters, all the orangarin monomers and oligomers exhibit very rapid excited-state decays.
RESUMEN
NiII porphyrin (P) and NiII 5,15-diazaporphyrin (DAP) hybrid tapes were synthesized by Suzuki-Miyaura cross-coupling reactions of meso- or ß-borylated P with ß-brominated DAP followed by intramolecular oxidative fusion reactions. Meso-ß doubly linked hybrid tapes were synthesized by oxidation of singly linked precursors with DDQ-FeCl3. Synthesis of triply linked hybrid tapes was achieved by oxidation with DDQ-FeCl3-AgOTf with suppression of peripheral ß-chlorination. In these tapes, DAP segments were present as a 20π-electronic unit, but their local antiaromatic contribution was trivial. Remarkably, these hybrid tapes were stable and exhibited extremely enhanced absorption bands in the NIR region and multiple reversible redox waves. A pentameric hybrid tape showed a remarkably sharp and red-shifted band at 1168 nm with ε = 5.75 × 105 M-1 cm-1. Singly linked P-DAP dyads were oxidized with DDQ-FeCl3 to give stable radicals, which were oxidized further to afford dimeric hybrid tapes possessing a nitrogen atom at the peripheral-side meso-position.
RESUMEN
Acid-catalyzed Friedel-Crafts-type cyclization of tetrapyrrolic BF2 complex 1 and α,α'-dibromotripyrrin 2 gave 5,10,23-trimesityl [28]heptaphyrin(1.1.0.0.1.0.0) BF2 complex 3BF2 as a stable and moderate antiaromatic macrocycle. Demetalation of 3BF2 with methanesulfonic acid followed by treatment with HCl gave free-base salt 3HCl that holds a chloride anion at the core. This salt displays a planar structure with an inverted pyrrole and a stronger paratropic ring current. Metalation of neutral free-base 3 with PdCl2 gave bis-PdII complex 3Pd2 as a stable antiaromatic molecule. The 1H NMR spectrum of 3Pd2 displays signals due to pyrrolic ß-protons in the range of -1.06 â¼ -1.90 ppm, indicating the unprecedented strong paratropic ring current.
RESUMEN
Quinoa is a full-nutrition food; however, its poor flavor and small size make it not the best food option for direct consumption. In this study, a quinoa snack (QS, a cake) was developed, and the aroma profile of the products was improved by adding jujube fruit powder (made from dried jujube fruits, from 5% to 30%). Gas chromatography mass spectrum (GC-MS) combined with electronic nose (e-nose) was applied for characterizing the aroma profiles of QS samples. Results showed a total of 26 aroma compounds were identified in QS samples by GC-MS, and 3-methylbutanol (from 1525 µg/kg in QS-30 to 3487 µg/kg in QS-0), ethanol (from 1126 µg/kg in QS-0 to 3581 µg/kg in QS-30), hexanal (from 125.6 µg/kg in QS-30 to 984.1 µg/kg in QS-0), and acetaldehyde (from 531.9 µg/kg in QS-30 to 191.1 µg/kg in QS-0) were common. The e-nose response of W1S (sensitive to methane, from 17.50 of QS-0 to 93.85 of QS-30) and W1W (sensitive to sulfur-organic compounds of e-nose, from 15.57 of QS-0 to 39.50 of QS-30) were significantly higher, and significant differences were presented among QS samples. In conclusion, the aroma profile of the QS sample was significantly (p < .05) enhanced by the addition of jujube powder, and QS-30 with the highest jujube content (30%) presented the strongest aroma profile. Moreover, QS samples with different additions of jujube powders could be well distinguished by principal component analysis (PCA), and the combination of e-nose and GC-MS was effective in the volatile profile analysis of QS samples.
RESUMEN
m-Pyripentaphyrins(1.0.0.0.0) were synthesized by Suzuki-Miyaura coupling of 3,5-bis(5-borylpyrrol-2-yl)-BODIPY with 2,6-dibromopyridine. Upon treatment with PhBCl2, pyripentaphyrin 1 provided mono- and bis-BIII complexes sequentially. The Mono-BIII complex shows a distorted tetrahedral coordinated BIII with a σ-phenyl ligand on the BIII and the bis-BIII complex shows an additional distorted tetrahedral coordinated BIII with a B-H bond. Bromination of the pyripentaphyrins with N-bromosuccinimide (NBS) resulted in regioselective formation of 8-bromopyripentaphyrins, which were dimerized to 8,8'-linked dimers by reductive coupling with Ni(cod)2. While all these pyripentaphyrins are nonaromatic, they exhibit characteristic broad absorption bands at long wavelength near the NIR region, indicating the presence of effective macrocyclic conjugation.
RESUMEN
Singly-linked aromatic [22]smaragdyrin BF2 complex dimer was synthesized by the reductive coupling of 16-brominated [22]smaragdyrin BF2 complex, which was oxidized to a stable diradical with PbO2. As the first example of fused smaragdyrin dimer, a fused [22]smaragdyrin BF2 complex dimer was synthesized by the oxidation of a CuCl-BF2 complex dimer with FeCl3 and subsequent reduction with NaBH4. After removal of the BF2 group, the singly-linked and fused aromatic dimers were oxidized to the corresponding antiaromatic [20]smaragdyrin free base dimers. The first oxidation and reduction potentials of these dimers are split depending upon the intramolecular electronic interactions, which are larger for the fused dimers. Despite the large electronic interactions, the aromatic and antiaromatic characters are well preserved in the fused dimers.
RESUMEN
Exploration of expanded porphyrins with unprecedented reactivities has remained important. Here [22]pentaphyrins(2.0.1.1.0) were synthesized as a constitutional isomer of sapphyrin by acid-catalyzed cyclization of 1,14-dibromo-5,10-diaryltripyrrin with 1,2-di(pyrro-2-ly)ethenes. These pentaphyrins display roughly planar structures and varying aromaticities depending upon the vinylene structures. The 19,20-ditolyl pentaphyrin gave an N-fused product and an unprecedented pyrrole-rearranged product, depending upon the oxidation conditions. Remarkably, upon the metalation with CuCl, the N-fused product and the pyrrole-rearranged product afforded an inner ß-ß coupled face-to-face CuII complex dimer and an outer ß-ß coupled lateral CuII complex dimer, respectively, in fairly good yields. Further, [22]pentaphyrin(2.0.1.1.0) fused with a NiII porphyrin was effectively dimerized upon oxidation with MnO2 to give a 16-16' directly linked dl-dimer.
RESUMEN
Carbazole-incorporated smaragdyrin BF2-complex 3 was synthesized by SNAr reaction of 3,5-dibromo-8-mesityl-BODIPY 1 with 3,6-di(tert-butyl)-1,8-di(pyrrol-2-yl)carbazole 2 as a nucleophile. Demetalation of 3 with ZrCl4 gave the corresponding smaragdyrin free base 4 in a good yield. Oxidations of 3 and 4 with MnO2 gave smaragdyrins 5 and 6, respectively, both followed by aromaticity switching, since the oxidized products showed a moderate paratropic ring current owing to their 20π-electronic circuits. Further, treatment of 4 with [RhCl(CO)2]2 in the presence of NaOAc gave RhI complex 7, and oxidation of 3 with RuCl3 in the presence of triethylamine led to the formation of a spiro dimer product, 8.
RESUMEN
Energy-efficient white light-emitting diodes (LEDs) are in high demand across the society. Despite the significant advancements in the modern lighting industry based on solid-state electronics and inorganic phosphor, solid-state lighting (SSL) continues to pursue improved efficiency, saturated color performance, and longer lifetime. Here in this article, robust, narrow emission band nanorods (NRs) are disclosed with tailored wavelengths, aiming to enhance the color rendering index (CRI) and luminous efficacy (LE). The fabricated lighting device consists of NRs of configuration CdSe/ZnxCd1-xS/ZnS, which can independently tune CRI R1-R9 values and maximize the luminous efficacy. For general lighting, NRs with quantum yield (QY) up to 96% and 99% are developed, resulting in ultra-efficient LEDs reaching a record high luminous efficacy of 214 lm W-1 (certified by the National Accreditation Service). Furthermore, NRs are deployed onto mid-power (0.3 W@ 50 mA) LEDs, showing significantly enhanced long-term stability (T95 = 400 h @ 50 mA). With these astonishing properties, the proposed NRs can pave the way for efficient lighting with desired optical spectrum.
RESUMEN
In this paper, the thermal performance of 54 horizontal-hole interlocking composite insulation blocks was numerically analyzed based on the steady-state heat transfer model, the regulations were found, and prediction models for the thermal parameters of the blocks were established based on the parallel network thermal resistance model. The influence of block types and block materials on the thermal performance was studied, and it was found that the thermal performance of H-shaped interlocking insulation blocks was better than that of crossed-shaped ones, and the lower the thermal conductivity of block materials, the better the thermal performance of blocks, among which the reduction of thermal conductivity of concrete materials improved the thermal performance of blocks the most. The simulated values of thermal conductivity of H-shaped interlocking insulation blocks and thermal conductivity under the parallel network thermal resistance model were highly linearly correlated with correlation coefficients as high as 0.998 and 0.999. This finding enables the prediction models of thermal parameters of H-shaped interlocking insulation blocks to be established with high accuracy and provides an effective guide for the energy-saving design of interlocking insulation blocks wall.
RESUMEN
Developing luminescent materials with suitable correlated color temperature (CCT) and sufficient color-rendering index (CRI) is a challenging problem in the field of commercialized warm white LED lighting. Herein, a novel metal-organic gel (MOG) material named YTU-G-1(SE) was synthesized, consisting of zirconium metal coordinated with 1,1,2,2-tetrakis(4-carboxyphenyl) ethylene. YTU-G-1(SE) exhibits strong fluorescent properties with an aggregation-induced emission (AIE) effect, emitting yellow-green fluorescence at 515 nm. The internal and external quantum efficiencies (IQE/EQE) of YTU-G-1(SE) are close to unity, with values of 95.74 ± 0.5% and 88.67 ± 0.5%, respectively. Finally, we combined YTU-G-1(SE) with a commercial blue chip and a commercial red phosphor (Sr,Ca)AlSiN3:Eu2+ to fabricate a warm white light LED with a color temperature of 3736 K, a color-rendering index Ra of 88.2, and a lumen efficiency of 79.42 lm W-1. This work provides a new approach to regulating the emission of AIE and offers a novel idea for developing high-performance warm-white pc-WLEDs.
RESUMEN
The efficient synthesis of nanosheets containing two metal ions is currently a formidable challenge. Here, we attempted to dope lanthanide-based bimetals into porphyrin-based metal-organic skeleton materials (MOFs) by microwave-assisted heating. The results of the EDX, ICP, and XPS tests show that we have successfully synthesized porphyrin-based lanthanide bimetallic nanosheets (Tb-Eu-TCPP) using a household microwave oven. In addition, it is tested and experimentally evident that these nanosheets have a thinner thickness, a larger BET surface area, and higher photogenerated carrier separation efficiency than bulk porphyrin-based bimetallic materials, thus exhibiting enhanced photocatalytic activity and n-type semiconductor properties. Furthermore, the prepared Tb-Eu-TCPP nanomaterials are more efficient in generating single-linear state oxygen under visible light irradiation compared to pristine monometallic nanosheets due to the generation of bimetallic nodes. The significant increase in catalytic activity is attributed to the improved separation and transfer efficiency of photogenerated carriers. This study not only deepens our understanding of lanthanide bimetallic nanosheet materials but also introduces an innovative approach to improve the photocatalytic performance of MOFs.
RESUMEN
BIII-subporphyrins 4, 5, and 6 possessing metal-coordinating carbaporphyrin-like pockets were synthesized by Suzuki-Miyaura coupling reactions. Compounds 4 and 5 gave PdII complexes 4-Pd and 5-Pd upon metalation with Pd(OAc)2 but did not give either their NiII or CuII complexes. Conversely, 6 was expected to induce distorted square planar coordination because of its 2,5-di(pyrid-2-yl)pyrrole strap. Indeed reaction of 6 with Cu(OAc)2 did not give its CuII complex but produced meso-alkoxy and meso-phenoxy products in the presence of alcohols and phenol, possibly via CuII-mediated C-H bond functionalization, which was further extended to meso-C-C bond-forming fabrications by using organoboronic acids. These CuII-mediated C-H bond meso-fabrications are the first example for porphyrinoid substrates.
RESUMEN
Norcorrole Ni(II) complexes have recently received considerable attention because they are readily accessible antiaromatic molecules. Their high stability under ambient conditions and ease of synthesis have enabled the exploration of the intrinsic properties of antiaromatic molecules. Here, we report the synthesis and properties of meso-meso singly linked porphyrin-norcorrole hybrids and a triply linked porphyrin-norcorrole hybrid. The singly linked and triply linked porphyrin-norcorrole hybrids were fully characterized, including an X-ray structural analysis. Due to their orthogonal conformation, the singly linked hybrids maintain the individual electronic properties of their porphyrin and norcorrole subunits, while the triply linked hybrid shows a significantly smaller electrochemical HOMO-LUMO gap (0.45â eV) than that of Ni(II) dimesitylnorcorrole (1.08â eV). Furthermore, the triply linked hybrid exhibits singlet diradical characteristics, as confirmed by VTâ NMR, ESR, and SQUID experiments.
RESUMEN
CuII metalations of carbaporphyrins 1-4 gave the corresponding CuII complexes 1-Cu, 2-Cu, 3-Cu, and 4-Cu with varying degrees of distortions in CuII square-planar coordination. Upon treatment with Cu(OAc)2, 1-Cu was inert but 2-Cu and 3-Cu gave the respective O-atom-inserted complexes 2-OCu and 3-OCu. Further, 3-Cu and 4-Cu were converted to meso-methoxynickel(II) porphyrins 3-OMe and 4-OMe, respectively, via treatment with Cu(OAc)2 in methanol. meso-Hydroxynickel(II) porphyrin 3-OH was obtained by the treatment of 3-OCu by acetic acid. The treatment of 4-Cu with Cu(OAc)2 in the presence of acetic acid gave 5,15-diketoporphyrinogen 4-O. CuII complexes of carbaporphyrins became more reactive with an increased distortion in CuII square-planar coordination.
RESUMEN
Cyclic azobenzene-BODIPY hybrids were synthesized via cyclization by 1) acid-catalysed condensation of azobenzene-bridged dipyrroles with 3,5-di-tert-butylbenzaldehyde, 2) oxidation with DDQ, and 3) metalation with BF3 â Et2 O. The structures of many cyclic hybrids have been confirmed by single crystal X-ray analysis. The absorption spectra of the hybrids reveal the effective cyclic conjugation. The ultrafast measurements reveal that the photoexcited decays of these cyclic hybrids depend upon the ring size and connectivity.
RESUMEN
Di(p-benzi)[40]decaphyrin(1.0.0.0.0.1.0.0.0.0) BF2 complex and tris(p-benzi)[60]pentadecaphyrin(1.0.0.0.0.1.0.0.0.0.1.0.0.0.0) BF2 complex were synthesized by Suzuki-Miyaura coupling of α,α'-diborylated tetrapyrrole BF2 -complex with 1,4-diiodobenzene. Bis-BF2 complex was converted to bis-PdII complex via its free base. Macrocycles bis-BF2 and tris-BF2 complex take Möbius topology but are nonaromatic, since the macrocyclic conjugation is disrupted by the locally aromatic 1,4-phenylene units. In contrast, bis-PdII complex is a weakly Hückel 38π-aromatic macrocycle as evinced by its red-shifted, enhanced, and structured Q-like bands and a small electrochemical HOMO-LUMO gap. Interestingly, one 1,4-pheylene part of bis-PdII complex takes a quinonoidal distorted structure and the other takes a usual benzene structure in a figure-eight conformation with Hückel topology.
RESUMEN
Pyrrole-sharing fused hybrids of NiII porphyrin with PdII N-confused(NC)-corrole and PdII NC-oxaporphyrin were synthesized by post-fabrication of NiII porphyrins. Specifically this consists of Friedel-Crafts type aromatic substitution reaction of meso-free NiII porphyrin with α,α'-dibromotripyrrin and Pd(OAc)2 assisted cyclization, and final heating to induce a Pd-C bond formation. NiII porphyrins fused with PdII NC-corrole and with PdII NC-oxaporphyrins show coplanar structures with a shared pyrrole unit. In these hybrids, the PdII NC-oxaporphyrin is aromatic and the PdII NC-corrole is moderately antiaromatic and these local electronic properties interact to influence the whole network.
RESUMEN
5,10,23-Trimesityl-substituted [24]hexaphyrin(1.1.0.0.1.0) was synthesized as a stable antiaromatic molecule by base-catalyzed twofold SNAr reaction and was reduced to the corresponding [26]hexaphyrin, which was an unstable aromatic molecule because it easily oxidized to the [24]hexaphyrin. The [24]hexaphyrin served as a ligand to give the bis-PdII complex and tris-RhI complex with unique structures. The former complex has two square-planar-coordinated PdII ions bridged by an acetate anion and shows a strong paratropic ring current, while the latter complex has three RhI ions coordinated with two pyrrolic nitrogen atoms and two carbonyl groups, but one carbonyl group is shared with two RhI ions in a unique manner.
