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Polymeric materials that undergo photoinduced degradation have wide application in fields such as controlled release. Most methods for photoinduced degradation rely on the UV or near-UV region of the electromagnetic spectrum; however, use of the deeply penetrating and benign wavelengths of visible light offers a multitude of advantages. Here we report a lactone monomer for ring-opening copolymerizations to introduce a sacrificial linker into a polymer backbone which can be cleaved by reactive oxygen species which are produced by a photocatalyst under visible light irradiation. We find that copolymers of this material readily degrade under visible light. We followed polymer degradation using a continuous flow size exclusion chromatography system, the components of which are described herein.
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1,2,6-Thiadiazines treated with visible light and 3O2 under ambient conditions are converted into difficult-to-access 1,2,5-thiadiazole 1-oxides (35 examples, yields of 39-100%). Experimental and theoretical studies reveal that 1,2,6-thiadiazines act as triplet photosensitizers that produce 1O2 and then undergo a chemoselective [3 + 2] cycloaddition to give an endoperoxide that ring contracts with selective carbon atom excision and complete atom economy. The reaction was optimized under both batch and continuous-flow conditions and is also efficient in green solvents.
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Regioselective stepwise phenylation of 4,7-diarylbenzo[c][1,2,5]thiadiazole fluorophores has been achieved through a facile one-pot, three-step synthetic strategy involving sequential borylation, hydroxydechlorination and Suzuki-Miyaura cross-coupling reactions. Crucial to the selectivity was the use of BCl3 to regioselectively install a boronic acid group in the ortho-position of only one of the diaryl groups. The subsequent introduction of ortho-phenyl groups through Suzuki-Miyaura cross-coupling gave rise to twisted structures with hindered intramolecular rotation, providing a structural lever with which the fluorophore absorption and emission properties could be adjusted.
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BACKGROUND: Although outcomes in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary interventions (PCI) have improved, women show higher mortality. OBJECTIVES: To assess gender differences in presentation, management and in-hospital mortality, at 30-days, 6-months and 1-year after STEMI. METHODS: We retrospectively collected data from 809 consecutive patients treated with primary PCI and compared the females versus males at the local intervention cardiology database. The level of significance used was p<0.05. RESULTS: Women were older than man (69,1±14,6 vs. 58,5±12,7 years; p<.001) with higher prevalence of age over 75 years (36.7% vs. 11.7%; p<.001), diabetes (30,6% vs. 18,5%; p=.001), hypertension (60.5% vs. 45.9%; p=.001), chronic kidney disease (3.4% vs. 0.6%; p=.010) and acute ischemic stroke (6.8% vs. 3.0%; p=.021). At presentation, women had more atypical symptoms, less chest pain (p=.014) and were more frequently in cardiogenic shock (p=.011)). Women had longer time until reperfusion (p=.001) and were less likely to receive optimal medical therapy (p<0.05). In-hospital mortality (p=.001), at 30-days (p<.001), 6-months (p<.001) and 1-year (16.4% vs. p<.001) was higher in women. The multivariate analysis identified age over 75 years (HR=4.25; 95% CI[1.67-10.77];p=.002), Killip class II (HR=8.80; 95% CI[2.72-28.41];p<.001), III (HR=5.88; 95% CI [0.99-34.80]; p=.051) and IV (HR=9.60; 95% CI[1.86-48.59];p=.007), Acute Kidney Injury (HR=2.47; 95% CI[1.00-6.13];p=.051) and days of hospitalization (HR=1.04; 95% CI[1.01-1.08];p=.030) but not female gender (HR=0.83; 95% CI[0.33-2.10];p=.690) as independent prognostic factors of mortality. CONCLUSIONS: Compared to men, women with STEMI undergoing primary PCI have higher mortality rates. Women admitted for STEMI have a worse risk profile, are treated with a higher reperfusion time related with system delays and are less likely to receive the recommended therapy. Female gender was not an independent prognostic factor for mortality in the studied population.
FUNDAMENTO: Embora os resultados em pacientes com infarto do miocárdio com supradesnivelamento do segmento ST (IAMCSST) submetidos a intervenções coronárias percutâneas (ICP) primárias tenham melhorado, as mulheres apresentam maior mortalidade. Objetivos: Avaliar as diferenças de gênero na apresentação, manejo e mortalidade hospitalar, em 30 dias, 6 meses e 1 ano após IAMCSST. MÉTODOS: Coletamos retrospectivamente dados de 809 pacientes consecutivos tratados com ICP primária e comparamos mulheres versus homens no banco de dados de cardiologia de intervenção local. O nível de significância utilizado foi p<0,05. RESULTADOS: As mulheres eram mais velhas que os homens (69,1±14,6 vs. 58,5±12,7 anos; p<0,001) com maior prevalência de idade acima de 75 anos (36,7% vs. 11,7%; p<0,001), diabetes (30,6% vs. 18,5%; p=0,001), hipertensão (60,5% vs. 45,9%; p=0,001), doença renal crônica (3,4% vs. 0,6%; p= 0,010) e acidente vascular cerebral isquêmico agudo (6,8% vs. 3,0%; p=0,021). Na apresentação, as mulheres apresentavam mais sintomas atípicos, menos dor torácica (p=0,014) e estavam mais frequentemente em choque cardiogênico (p=0,011)). As mulheres tinham mais tempo até a reperfusão (p=0,001) e eram menos propensas a receber terapia médica ideal (p<0,05). A mortalidade intra-hospitalar (p=0,001), em 30 dias (p<0,001), 6 meses (p<0,001) e 1 ano (16,4% vs. p<0,001) foi maior nas mulheres. A análise multivariada identificou idade acima de 75 anos (HR=4,25; IC 95%[1,67-10,77];p=0,002), classe Killip II (HR=8,80; IC 95%[2,72-28,41];p<0,001), III (HR=5,88; IC95% [0,99-34,80]; p=0,051) e IV (HR=9,60; IC 95%[1,86-48,59];p=0,007), Lesão Renal Aguda (HR=2,47; IC 95% [1,00-6,13];p=0,051) e dias de hospitalização (HR=1,04; IC 95%[1,01-1,08];p=0,030), mas não o sexo feminino (HR=0,83; IC95% [0,33-2,10];p=0,690) como fatores prognósticos independentes de mortalidade. CONCLUSÕES: Comparadas aos homens, as mulheres com IAMCSST submetidas à ICP primária apresentam maiores taxas de mortalidade. Mulheres hospitalizadas por IAMCSST têm pior perfil de risco, são tratadas com maior tempo de reperfusão relacionado a atrasos do sistema e têm menor probabilidade de receber a terapia recomendada. O sexo feminino não foi fator prognóstico independente para mortalidade na população estudada.
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AVC Isquêmico , Infarto do Miocárdio , Intervenção Coronária Percutânea , Infarto do Miocárdio com Supradesnível do Segmento ST , Humanos , Masculino , Feminino , Idoso , Infarto do Miocárdio com Supradesnível do Segmento ST/terapia , Estudos Retrospectivos , AVC Isquêmico/etiologia , Fatores de Risco , Resultado do Tratamento , Mortalidade HospitalarRESUMO
Resumo Fundamento Embora os resultados em pacientes com infarto do miocárdio com supradesnivelamento do segmento ST (IAMCSST) submetidos a intervenções coronárias percutâneas (ICP) primárias tenham melhorado, as mulheres apresentam maior mortalidade. Objetivos: Avaliar as diferenças de gênero na apresentação, manejo e mortalidade hospitalar, em 30 dias, 6 meses e 1 ano após IAMCSST. Métodos Coletamos retrospectivamente dados de 809 pacientes consecutivos tratados com ICP primária e comparamos mulheres versus homens no banco de dados de cardiologia de intervenção local. O nível de significância utilizado foi p<0,05. Resultados As mulheres eram mais velhas que os homens (69,1±14,6 vs. 58,5±12,7 anos; p<0,001) com maior prevalência de idade acima de 75 anos (36,7% vs. 11,7%; p<0,001), diabetes (30,6% vs. 18,5%; p=0,001), hipertensão (60,5% vs. 45,9%; p=0,001), doença renal crônica (3,4% vs. 0,6%; p= 0,010) e acidente vascular cerebral isquêmico agudo (6,8% vs. 3,0%; p=0,021). Na apresentação, as mulheres apresentavam mais sintomas atípicos, menos dor torácica (p=0,014) e estavam mais frequentemente em choque cardiogênico (p=0,011)). As mulheres tinham mais tempo até a reperfusão (p=0,001) e eram menos propensas a receber terapia médica ideal (p<0,05). A mortalidade intra-hospitalar (p=0,001), em 30 dias (p<0,001), 6 meses (p<0,001) e 1 ano (16,4% vs. p<0,001) foi maior nas mulheres. A análise multivariada identificou idade acima de 75 anos (HR=4,25; IC 95%[1,67-10,77];p=0,002), classe Killip II (HR=8,80; IC 95%[2,72-28,41];p<0,001), III (HR=5,88; IC95% [0,99-34,80]; p=0,051) e IV (HR=9,60; IC 95%[1,86-48,59];p=0,007), Lesão Renal Aguda (HR=2,47; IC 95% [1,00-6,13];p=0,051) e dias de hospitalização (HR=1,04; IC 95%[1,01-1,08];p=0,030), mas não o sexo feminino (HR=0,83; IC95% [0,33-2,10];p=0,690) como fatores prognósticos independentes de mortalidade. Conclusões Comparadas aos homens, as mulheres com IAMCSST submetidas à ICP primária apresentam maiores taxas de mortalidade. Mulheres hospitalizadas por IAMCSST têm pior perfil de risco, são tratadas com maior tempo de reperfusão relacionado a atrasos do sistema e têm menor probabilidade de receber a terapia recomendada. O sexo feminino não foi fator prognóstico independente para mortalidade na população estudada.
Abstract Background Although outcomes in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary interventions (PCI) have improved, women show higher mortality. Objectives To assess gender differences in presentation, management and in-hospital mortality, at 30-days, 6-months and 1-year after STEMI. Methods We retrospectively collected data from 809 consecutive patients treated with primary PCI and compared the females versus males at the local intervention cardiology database. The level of significance used was p<0.05. Results Women were older than man (69,1±14,6 vs. 58,5±12,7 years; p<.001) with higher prevalence of age over 75 years (36.7% vs. 11.7%; p<.001), diabetes (30,6% vs. 18,5%; p=.001), hypertension (60.5% vs. 45.9%; p=.001), chronic kidney disease (3.4% vs. 0.6%; p=.010) and acute ischemic stroke (6.8% vs. 3.0%; p=.021). At presentation, women had more atypical symptoms, less chest pain (p=.014) and were more frequently in cardiogenic shock (p=.011)). Women had longer time until reperfusion (p=.001) and were less likely to receive optimal medical therapy (p<0.05). In-hospital mortality (p=.001), at 30-days (p<.001), 6-months (p<.001) and 1-year (16.4% vs. p<.001) was higher in women. The multivariate analysis identified age over 75 years (HR=4.25; 95% CI[1.67-10.77];p=.002), Killip class II (HR=8.80; 95% CI[2.72-28.41];p<.001), III (HR=5.88; 95% CI [0.99-34.80]; p=.051) and IV (HR=9.60; 95% CI[1.86-48.59];p=.007), Acute Kidney Injury (HR=2.47; 95% CI[1.00-6.13];p=.051) and days of hospitalization (HR=1.04; 95% CI[1.01-1.08];p=.030) but not female gender (HR=0.83; 95% CI[0.33-2.10];p=.690) as independent prognostic factors of mortality. Conclusions Compared to men, women with STEMI undergoing primary PCI have higher mortality rates. Women admitted for STEMI have a worse risk profile, are treated with a higher reperfusion time related with system delays and are less likely to receive the recommended therapy. Female gender was not an independent prognostic factor for mortality in the studied population.
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Background: The occurrence of bone fractures is increasing worldwide, mainly due to the health problems that follow the aging population. The use of additive manufacturing and electrical stimulators can be applied for bioactive achievements in bone healing. However, such technologies are difficult to be transferred to medical practice. This work aims to develop an orthosis with a combined magnetic field (CFM) electrostimulator that demonstrates concepts and design aspects that facilitate its use in a real scenario. Methods: A 3D-printed orthosis made of two meshes was manufactured using PLA for outer mechanical stabilization mesh and TPU for inner fixation mesh to avoid mobilization. A CFM stimulator of reduced dimension controlled by a mobile application was coupled onto the orthosis. The design concepts were evaluated by health professionals and their resistance to chemical agents commonly used in daily activities were tested. Their thermal, chemical and electrical properties were also characterized. Results: No degradation was observed after exposure to chemical agents. The CMF achieved proper intensity (20-40 µT). The thermal analysis indicated its appropriate use for being modelled during clinical assessment. Conclusion: An orthosis with a coupled electrostimulator that works with a combined magnetic field and is controlled by mobile application was developed, and it has advantageous characteristics when compared to traditional techniques for application in real medical environments.
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Porous organic polymers (POPs) have been prepared via a novel metal free polycondensation between a tritopic indole-based monomer and squaric, croconic and rhodizonic acids. Each of the three POPs exhibited high BET surface areas (331-667 m2 g-1) and zwitterionic structures. Impedance measurements revealed that the intrinsic POPs were relatively weak proton conductors, with a positive correlation between the density of oxo-groups and the proton conduction. Doping the materials with LiCl vastly improved the proton conductivity up to a value of 0.54 S cm-1 at 90 °C and 90% relative humidity.
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Tetrazoles play a prominent role in medicinal chemistry due to their role as carboxylate bioisosteres but have largely been overlooked as C-H functionalisation substrates. We herein report the development of a high-yielding and general procedure for the heterobenzylic C-H functionalisation of 5-alkyltetrazoles in up to 97% yield under batch conditions using a metalation/electrophilic trapping strategy. Through the use of thermal imaging to identify potentially unsafe exotherms, a continuous flow procedure using a flash chemistry strategy has also been developed, allowing products to be accessed in up to 95% yield. This enabled an extremely high productivity rate of 141 g h-1 to be achieved on an entry-level flow system.
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The datasets in this work contain the experimentally measured (real) refractive indices, optical transmission intensity, and optical absorption spectra of bifunctional urethane methacrylate perfluoropolyether (PFPE; Fluorolink® MD700) substrate of (0.98 ± 0.13) mm thickness and polyvinylidene fluoride (PVDF; Kynar® 705) thin-film of (4.47 ± 0.29) µm thickness over a spectral range from 300 nm to 1000 nm, as measured via variable angle spectroscopic ellipsometry. The refractive indices data were determined by employing a single Cauchy optical constants function based layer using a Levenberg-Marquardt multi-iterative regression algorithm for all model minimizations. The mean-squared error (MSE) was used as the maximum likelihood estimator, with a convergence of the Levenberg-Marquardt algorithm reached when successive iterations were unable to improve the MSE. The resulting best-fit parameter values were evaluated for sensitivity (expressed as a confidence limit), and possible correlations. Furthermore, the experimentally measured optical transmission intensity and determined optical absorption of PFPE and PVDF, over a spectral range from 300 nm to 1000 nm, is also presented, as measured via ellipsometry and corrected using Fresnel equations to accommodate surface interference. Given the high transmission of (88.4 ± 0.5)% for PFPE and (95.6 ± 0.6) % for PVDF found, and the low refractive index 1.27 (λ = 589.3 nm) found for PFPE; it is thought that these datasets may be useful for optical applications, such as for photo-curable synthesis processes, or being used as a host-matrix material for photoluminescent compounds.
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Recent advancements in in-line extraction and purification technology have enabled complex multistep synthesis in continuous flow reactor systems. However, for the large scope of chemical reactions that yield mixtures of products or residual starting materials, off-line purification is still required to isolate the desired compound. We present the in-line integration of a commercial automated flash chromatography system with a flow reactor for the continuous synthesis and isolation of product(s). A proof-of-principle study was performed to validate the system and test the durability of the column cartridges, performing an automated sequence of 100 runs over 2 days. Three diverse reaction systems that highlight the advantages of flow synthesis were successfully applied with in-line normal- or reversed-phase flash chromatography, continuously isolating products with 97-99% purity. Productivity of up to 9.9 mmol/h was achieved, isolating gram quantities of pure product from a feed of crude reaction mixture. Herein, we describe the development and optimization of the systems and suggest guidelines for selecting reactions well suited to in-line flash chromatography.
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Cromatografia de Fase Reversa , Fenômenos FísicosRESUMO
A new benzothiadiazole (BTZ) luminogen is prepared via the Suzuki-Miyaura Pd-catalysed C-C cross-coupling of 8-iodoquinolin-4(1H)-one and a BTZ bispinacol boronic ester. The rapid reaction (5 min) affords the air-, thermo-, and photostable product in 97% yield as a yellow precipitate that can be isolated by filtration. The luminogen exhibits aggregated-induced emission (AIE) properties, which are attributed to its photoactive BTZ core and nonplanar geometry. It also behaves as a molecular heterogeneous photosensitizer for the production of singlet oxygen under continuous flow conditions.
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Two robust and efficient mechanochemical protocols for the synthesis of an array of N-arylamides have been developed. This was achieved by a C-N cross-coupling between O-pivaloyl hydroxamic acids and aryl iodides or aryl boronic acids, in the presence of a stoichiometric amount of a copper mediator. The effectiveness of this method is highlighted by the high-yielding (up to 94 %), scalable (up to 8â mmol), and rapid (20 minutes) synthesis of N-aryl amides (15 examples), using a variety of deactivated and sterically encumbered substrates, whilst employing mild conditions and in the absence of solvents. In addition, it was determined that whilst the O-pivaloyl hydroxamic acid precursors can be synthesised mechanochemically, iron contamination originating from the steel jars was found to occur which can hinder the efficacy of this process. Furthermore, 3D printing was used to produce custom milling jars that could successfully accommodate a scaled-up version of the two protocols.
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The synergy between photocatalysis and continuous flow chemical reactors has shifted the paradigms of photochemistry, opening new avenues of research with safer and scalable processes that can be readily implemented in academia and industry. Current state-of-the-art photocatalysts are homogeneous transition metal complexes that have favourable photophysical properties, wide electrochemical redox potentials, and photostability. However, these photocatalysts present serious drawbacks, such as toxicity, limited availability, and the overall cost of rare transition metal elements. This reduces their long-term viability, especially at an industrial scale. Heterogeneous photocatalysts (HPCats) are an attractive alternative, as the requirement for the separation and purification is largely removed, but typically at the cost of efficiency. Flow chemical reactors can, to a large extent, mitigate the loss in efficiency through reactor designs that enhance mass transport and irradiation. Herein, we review some important developments of heterogeneous photocatalytic materials and their application in flow reactors for sustainable organic synthesis. Further, the application of continuous flow heterogeneous photocatalysis in environmental remediation is briefly discussed to present some interesting reactor designs that could be implemented to enhance organic synthesis.
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A series of novel bimetallic TiIV amine bis(phenolate) complexes was synthesised and fully characterised. X-ray crystallography studies revealed distorted octahedral geometries around the Ti centres with single or double oxo-bridges connecting the two metals. These robust, air- and moisture-stable complexes were employed as photosensitisers generating singlet oxygen following irradiation with visible light (420â nm) LED module in a commercial flow reactor. All five complexes showed high activity in the photo-oxygenation of α-terpinene and achieved complete conversion to ascaridole in four hours at ambient temperature. The excellent selectivity of these photosensitisers towards ascaridole (vs. transformation to p-cymene) was demonstrated with control experiments using a traditional TiO2 catalyst. Further comparative studies employing the free pro-ligands as well as a monometallic analogue highlighted the importance of the 'TiO2 -like' moiety in the polymetallic catalysts. Computational studies were used to determine the nature of the ligand to metal charge transfer (LMCT) states and singlet-triplet gaps for each complex, the calculated trends in the UV-vis absorption spectra across the series agreed well with the experimental results.
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Conjugated porous polymers (CPPs) are a class of amorphous polymer networks that are, in their design, fully cross-linked and fully π-conjugated. The cross-linked nature of CPPs means that they have permanent intrinsic porosity (on the nanometer scale), which, in combination with the fully π-conjugated framework, makes these materials unique among the wider class of porous polymeric materials. In recent years, the need for new and efficient functional materials has driven the development of CPPs as versatile platforms for applications including (photo)catalysis, light harvesting, gas separation and storage, chemosensing, environmental remediation and energy storage. The efficiency of these materials towards these described applications is heavily influenced by the choice of molecular building blocks and synthetic conditions, allowing for facile tailoring and optimisation of the structure and properties. The aim of this review is to highlight select works on CPPs, including basic structural design principles, various synthetic protocols and topical applications of these versatile materials.
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Pd(II)-catalyzed desymmetrization of polycyclic cyclohexenediones has been achieved with high enantio- and diastereoselectivities. Up to five contiguous stereocenters are desymmetrized, while simultaneously, an additional stereocenter is created by the enantioselective conjugate addition. Surprisingly, the conjugate addition products dominate even under typical oxidative Heck conditions, and these observations may provide some insight into the competition between the two related reactions.
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1,3,4-Oxadiazoles are a common motif in pharmaceutical chemistry, but few convenient methods for their modification exist. A fast, convenient, high yielding and general α-substitution of 1,3,4-oxadiazoles has been developed using a metalation-electrophilic trapping protocol both in batch and under continuous flow conditions in contradiction to previous reports which suggest that α-metalation of this ring system results in ring fragmentation. In batch, lithiation is accomplished at an industrially convenient temperature, -30 °C, with subsequent trapping giving isolated yields of up to 91 %. Under continuous flow conditions, metalation is carried out at room temperature, and subsequent in flow electrophilic trapping gave up to quantitative isolated yields. Notably, lithiation in batch at room temperature results only in ring fragmentation and we propose that the superior mixing in flow allows interception and exploitation of an unstable intermediate before decomposition can occur.
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The Cu-catalyzed azide-alkyne cycloaddition (CuAAC) reaction is a cornerstone method for the ligation of biomolecules. However, undesired Cu-mediated oxidation and Cu-contamination in bioconjugates limits biomedical utility. Here, we report a generic CuAAC flow platform for the rapid, robust, and broad-spectrum formation of discrete triazole bioconjugates. This process leverages an engineering problem to chemical advantage: solvent-mediated Cu pipe erosion generates ppm levels of Cu in situ under laminar flow conditions. This is sufficient to catalyze the CuAAC reaction of small molecule alkynes and azides, fluorophores, marketed drug molecules, peptides, DNA, and therapeutic oligonucleotides. This flow approach, not replicated in batch, operates at ambient temperature and pressure, requires short residence times, avoids oxidation of sensitive functional groups, and produces products with very low ppm Cu contamination.
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Alcinos/química , Azidas/química , Cobre/química , Reação de Cicloadição/métodos , Catálise , Reação de Cicloadição/instrumentação , Estrutura Molecular , Oligonucleotídeos/síntese química , Oligonucleotídeos/química , Oxirredução , Peptídeos/síntese química , Peptídeos/química , Temperatura , Triazóis/síntese química , Triazóis/química , Água/químicaRESUMO
We employ a two-step strategy for accessing crystalline porous covalent networks of highly conjugated π-electron systems. For this, we first assembled a crystalline metal-organic framework (MOF) precursor based on Zr(iv) ions and a linear dicarboxyl linker molecule featuring backfolded, highly unsaturated alkyne backbones; massive thermocyclization of the organic linkers was then triggered to install highly conjugated, fused-aromatic bridges throughout the MOF scaffold while preserving the crystalline order. The formation of cyclized carbon links not only greatly strengthens the precursor coordination scaffold, but also, more importantly, enhances electroactivity and charge transport throughout the polycyclic aromatic grid.