Post-synthetic sulfonation of a diphenylanthracene based porous aromatic framework

Post-synthetic modification is an alternative pathway to introduce functionalities into the backbone of porous materials. Sulfonation of porous organic polymers is one of the frequently applied post-functionalization since the sulfonate groups are interesting for various applications such as carbon dioxide storage, proton conduction, ion removal. Moreover, sulfonation drastically improve hydrophilicity of the hydrophobic materials, therefore, makes the final compounds more processable in aqueous media. In this article, a procedure for post-synthetic sulfonation of a diphenylanthracene (DPA) based porous aromatic framework (DPA-PAF) is presented. Oleum (fuming sulfuric acid) was used as the sulfonation agent in acetic acid+water media instead of the conventionally used chlorosulfonic acid in the chlorinated solvents. Aside from macroscopic (visual) observations such as improved dispersibility in water when compared to the parent compound, the introduction of sulfonate groups was confirmed by using infra-red spectroscopy, elemental analysis, and gas sorption (surface area) measurements

Have covalent organic framework films revealed their full potential?

Porous organic polymers provide high accessible surface areas, which make them attrac-tive for gas storage, separation, and catalysis. In addition to those classical usage areas, such compounds are particularly interesting for electronic applications since their high dimensional, electron-rich backbone provides advanced electronic and photophysical properties. However, their non-sol-uble nature is a challenge for their processability, especially in the case of film formation, hence their limited utilization in organic electronic devices so far. Nevertheless, there are several techniques presented in the literature to overcome that issue, most of which were on the crystalline porous organic polymers, namely covalent organic frameworks (COFs). In this perspective, the develop-ments on COF film formation and prospects for the improvements are discussed with suggestions to further their performances in organic electronics

Triplet-triplet annihilation based near infrared to visible molecular photon upconversion

Triplet-triplet annihilation based molecular photon upconversion (TTA-UC) is an exciting research area for a broad range of photonic applications due to its tunable spectral range and possible operation at non-coherent solar irradiance. Most of the TTA-UC studies are limited to Visible to Visible (Vis to Vis) energy upconversion. However, for several practical photonic applications, efficient near infrared (NIR) to Vis upconversion is preferred. Examples include, (i) photovoltaics where TTA-UC could lead to utilization of a larger part of the solar spectrum and (ii) in NIR stimulated biological applications where the deep penetration and non-invasive nature of NIR light coupled to TTA-UC offers new opportunities. Although, NIR to Vis TTA-UC is known since 2007, the recent five years have witnessed quite a progress in terms of the development of new chromophores, hybrid systems and fabrication techniques to increase the UC quantum yield at low excitation intensity. With this tutorial review we are reviewing recent progress, identifying existing challenges and discus possible future directions and opportunities

Intramolecular Triplet-Triplet Annihilation Photon Upconversion in Diffusionally Restricted Anthracene Polymer

In the strive to develop triplet-triplet annihilation photon upconversion (TTA-UC) to become applicable in a viable technology, there is a need to develop upconversion systems that can function well in solid states. One method to achieve efficient solid-state TTA-UC systems is to replace the intermolecular energy-transfer steps with the corresponding intramolecular transfers, thereby minimizing loss channels involved in chromophore diffusion. Herein, we present a study of photon upconversion by TTA internally within a polymeric annihilator network (iTTA). By the design of the annihilator polymer and the choice of experiment conditions, we isolate upconversion emission governed by iTTA within the annihilator particles and eliminate possible external TTA between separate annihilator particles (xTTA). This approach leads to mechanistic insights into the process of iTTA and makes it possible to explore the upconversion kinetics and performance of a polymeric annihilator. In comparison to a monomeric upconversion system that only functions using xTTA, we show that upconversion in a polymeric annihilator is efficient also at extremely low annihilator concentrations and that the overall kinetics is significantly faster. The presented results show that intramolecular photon upconversion is a versatile concept for the development of highly efficient solid-state photon upconversion materials

Copper‐Free Sonogashira Coupling for High‐Surface‐Area Conjugated Microporous Poly(aryleneethynylene) Networks

A modified one‐pot Sonogashira cross‐coupling reaction based on a copper‐free methodology has been applied for the synthesis of conjugated microporous poly(aryleneethynylene) networks (CMPs) from readily available iodoarylenes and 1,3,5‐triethynylbenzene. The polymerization reactions were carried out by using equimolar amounts of halogen and terminal alkyne moieties with extremely small loadings of palladium catalyst as low as 0.65 mol %. For the first time, CMPs with rigorously controlled structures were obtained without any indications of side reactions, as proven by FTIR and solid‐state NMR spectroscopy, while showing Brunauer–Emmett–Teller (BET) surface areas higher than any poly(aryleneethynylene) network reported before, reaching up to 2552 m2 g−1.EC/FP7/278593/EU/Organic Zeolites/ORGZEODFG, 53182490, EXC 314: Unifying Concepts in Catalysi

Improved latent heat storage properties through mesopore enrichment of a zeolitic shape stabilizer

Latent heat storage systems are applied to keep temperature of a local environment within a constant range. The process takes place via release/storage of latent heat during freezing/melting of a corresponding phase change material embedded in a shape stabilizer, which is the scaffold keeping the phase change material stationary in its molten form. In this work, a highly siliceous ZSM-5 and modified versions thereof were chosen as shape stabilizers for molecular and polymeric phase change materials (namely lauric acid and polyethylene glycol), to be impregnated using solvent assisted vacuum impregnation. The dominantly microporous analogues, parent ZSM-5 and its acid-treated derivative, were limited to 40% uptake for each phase change material. Contrastingly, a mesopore rich analogue (as formed under basic conditions) reached 65% impregnation for lauric acid and 70% for polyethylene glycol, without any leakage at 70 \ub0C, resulting in latent heats of 106.9 J/g and 118.6 J/g for each composite, respectively. A simple prototypical real-world application demonstrated that the prepared lauric acid and polyethylene glycol composites of mesopore enriched ZSM-5 could maintain their temperatures up to 27% and 22% lower than the ambient environment under solar heating, as well as up to 20% and 26% higher when solar heating stops. The presented findings indicate mesopore enrichment improves phase change material uptake in these low cost, non-toxic zeolitic shape stabilizers, hence making them good candidates as isolation materials to address energy loss during heating/cooling of household environments

Recyclable optical bioplastics platform for solid state red light harvesting via triplet-triplet annihilation photon upconversion

Sustainable photonics applications of solid-state triplet-triplet annihilation photon upconversion (TTA-UC) are limited by a small UC spectral window, low UC efficiency in air, and non-recyclability of polymeric materials used. In a step to overcome these issues, we have developed new recyclable TTA-UC bioplastics by encapsulating TTA-UC chromophores liquid inside the semicrystalline gelatin films showing broad-spectrum upconversion (red/far-red to blue) with high UC efficiency in air. For this, we synthesized a new anionic annihilator, sodium-TIPS-anthracene-2-sulfonate (TIPS-AnS), that combined with red/far-red sensitizers (PdTPBP/Os(m-peptpy)2(TFSI)2), a liquid surfactant Triton X-100 reduced (TXr) and protein gelatin (G) formed red/far-red to blue TTA-UC bioplastic films just by air drying of their aqueous solutions. The G-TXr-TIPS-AnS-PdTPBP film showed record red to blue (633 to 478 nm) TTA-UC quantum yield of 8.5% in air. The high UC quantum yield has been obtained due to the fluidity of dispersed TXr containing chromophores and oxygen blockage by gelatin fibers that allowed efficient diffusion of triplet excited chromophores. Further, the G-TXr-TIPS-AnS-Os(m-peptpy)2(TFSI)2 bioplastic film displayed far-red to blue (700-730 nm to 478 nm) TTA-UC, demonstrating broad-spectrum photon harvesting. Finally, we demonstrated the recycling of G-TXr-TIPS-AnS-PdTPBP bioplastics by developing a downstream approach that gives new directions for designing future recyclable photonics bioplastic materials.Pankaj Bharmoria acknowledges Marie Skłodowska-Curie Actions – European Commission post-doctoral grant (NIRLAMS, Grant agreement ID: 844972) for research funding. Hakan Bildirir and Kasper Moth-Poulsen acknowledges funding from the Swedish Energy Agency, the Swedish Research Agency FORMAS, the Swedish Strategic Foundation, and the K & A Wallenberg foundation. Bo Albinsson acknowledges Swedish Energy Agency and the Swedish Research Council (VR). Nobuhiro Yanai acknowledges JSPS KAKENHI (grant numbers JP20H02713, JP20K21211, JP20H05676, JP18J21140).With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).Peer reviewe

Synthesis of Functional Microporous Polymers for Catalytic and Electronic Applications

Poröse Materialien zeichnen sich durch ihre vielfältigen Anwendungsmöglichkeiten in Bereichen wie der heterogenen Katalyse oder der Gastrennung und –Speicherung aus. Neben den anorganischen Materialien wie Zeolithen und porösen Kohlenstoffen rücken auch immer mehr organische Materialien, wie z.B. mikroporöse Polymere, in den Fokus der Forschung. Diese Netzwerke bestehen aus kovalent verbundenen, organischen Bausteinen. Daher lassen sich durch die Variation der Bausteine Netzwerke unterschiedlichster Funktionalitäten synthetisieren und so Materialien mit hoher chemischer und thermischer Stabilität erhalten. Diese Variabilität ist mit rein anorganischen oder Hybridmaterialien schwer zu erreichen. Daher ist die Entwicklung von Materialien für spezifische Anwendungen durch gezieltes Einbringen von funktionellen Gruppen eines der Hauptziele in der Synthese von porösen Materialien. Durch den Einsatz von elektronenreichen, organischen Molekülen in der Synthese von porösen Netzwerken können diese für Anwendungen im Bereich der organischen Elektronik oder Photokatalyse genutzt werden. Die vorliegende Arbeit beschreibt die Synthese von neuartigen, porösen Polymeren basierend auf schwefelhaltigen, π-konjugierten Monomeren und ist thematisch in zwei Teile bezüglich deren Anwendungsmöglichkeiten unterteilt: 1. Synthese von funktionalisierten Polymernetzwerken für die organische Elektronik; In diesem Teil werden Untersuchungen zum Einbau von starken Elektronendonatoren wie Tetrathiafulvalene (TTF) und Dithienothiophene (DTT) in konjugierte mikroporöse Polymere (CMP) vorgestellt. Die sich ausbildenden Charge-Transfer Verbindungen, welche durch die Exposition von Iod entstehen, werden genauer untersucht und beschrieben. Zusätzlich wird die elektrochemische Polymerisation von DTT untersucht und Vergleiche zum chemisch hergestellten Material im Bezug auf chemisch und elektrochemische Redoxeigenschaften sowie deren (opto)elektronischen Eigenschaften untersucht. Neben der Synthese der neuartigen Elektronendonatoren wird auch der Reaktionsmechanismus, welcher dem Aufbau dieser Netzwerke durch Sonogashira Hagihara Kreuzkupplung zugrunde liegt untersucht wobei das Hauptaugenmerk auf dem Verhältnis der Monomere sowie dem Einfluss des Reaktionsmediums liegt. 2. Synthese von funktionalisierten Polymernetzwerken für die Photokatalyse; In diesem Teil der Arbeit wird der Einbau eines häufig verwendeten Photoninitiators für die Photopolymerisation, Thioxanthone, in mikroporöse Polymere durch zwei verschiedene Polykondensationen vorgestellt. Diese Netzwerke werden als Photoinitiatoren in der heterogenen Initiierung der Polymerisation von Methylmetacrylat und Cyclohexenoxid, sowohl unter künstlichem als auch Tageslicht genutzt

Synthese von funktionalisierten, mikroporösen Polymernetzwerken für katalytische und elektronische Anwendungen

Poröse Materialien zeichnen sich durch ihre vielfältigen Anwendungsmöglichkeiten in Bereichen wie der heterogenen Katalyse oder der Gastrennung und –Speicherung aus. Neben den anorganischen Materialien wie Zeolithen und porösen Kohlenstoffen rücken auch immer mehr organische Materialien, wie z.B. mikroporöse Polymere, in den Fokus der Forschung. Diese Netzwerke bestehen aus kovalent verbundenen, organischen Bausteinen. Daher lassen sich durch die Variation der Bausteine Netzwerke unterschiedlichster Funktionalitäten synthetisieren und so Materialien mit hoher chemischer und thermischer Stabilität erhalten. Diese Variabilität ist mit rein anorganischen oder Hybridmaterialien schwer zu erreichen. Daher ist die Entwicklung von Materialien für spezifische Anwendungen durch gezieltes Einbringen von funktionellen Gruppen eines der Hauptziele in der Synthese von porösen Materialien. Durch den Einsatz von elektronenreichen, organischen Molekülen in der Synthese von porösen Netzwerken können diese für Anwendungen im Bereich der organischen Elektronik oder Photokatalyse genutzt werden. Die vorliegende Arbeit beschreibt die Synthese von neuartigen, porösen Polymeren basierend auf schwefelhaltigen, π-konjugierten Monomeren und ist thematisch in zwei Teile bezüglich deren Anwendungsmöglichkeiten unterteilt: 1. Synthese von funktionalisierten Polymernetzwerken für die organische Elektronik; In diesem Teil werden Untersuchungen zum Einbau von starken Elektronendonatoren wie Tetrathiafulvalene (TTF) und Dithienothiophene (DTT) in konjugierte mikroporöse Polymere (CMP) vorgestellt. Die sich ausbildenden Charge-Transfer Verbindungen, welche durch die Exposition von Iod entstehen, werden genauer untersucht und beschrieben. Zusätzlich wird die elektrochemische Polymerisation von DTT untersucht und Vergleiche zum chemisch hergestellten Material im Bezug auf chemisch und elektrochemische Redoxeigenschaften sowie deren (opto)elektronischen Eigenschaften untersucht. Neben der Synthese der neuartigen Elektronendonatoren wird auch der Reaktionsmechanismus, welcher dem Aufbau dieser Netzwerke durch Sonogashira Hagihara Kreuzkupplung zugrunde liegt untersucht wobei das Hauptaugenmerk auf dem Verhältnis der Monomere sowie dem Einfluss des Reaktionsmediums liegt. 2. Synthese von funktionalisierten Polymernetzwerken für die Photokatalyse; In diesem Teil der Arbeit wird der Einbau eines häufig verwendeten Photoninitiators für die Photopolymerisation, Thioxanthone, in mikroporöse Polymere durch zwei verschiedene Polykondensationen vorgestellt. Diese Netzwerke werden als Photoinitiatoren in der heterogenen Initiierung der Polymerisation von Methylmetacrylat und Cyclohexenoxid, sowohl unter künstlichem als auch Tageslicht genutzt.Porous materials have been a topic of interest in materials chemistry because of their high potential for various applications such as heterogeneous catalysis and gas storage. Beside the common porous materials, such as zeolites or activated carbons, some novel “soft” porous materials, namely organic microporous polymers, have been a focus of recent research, as the covalently bonded organic backbone enables high chemical and thermal stability with wide range specific functionalities while such properties are difficult to combine in inorganic or organic-inorganic hybrid systems. Thus, the introduction of suitable functionality into the porous backbone with high surface area is considered as one of the main targets in the field of porous polymers with the aim to develop properties for specific applications. In this context, organic porous networks based on electron rich building-blocks can extend the applicability of such materials to organic electronics or light driven catalytic systems. The present work focuses on the synthesis of novel porous polymers based on sulphur containing, π-conjugated functional monomers and is divided into two main topics according to the targeted applications: 1. Synthesis of functional polymer networks for organic electronic applications; In this work, investigations related to the introduction of strong electron donors such as tetrathiafulvalene (TTF) and dithienothiophene (DTT) into conjugated microporous polymer (CMP) backbone will be presented. The subsequent formation of corresponding charge-transfer salts after iodine exposure of these electron rich moieties will be discussed. Furthermore, electrochemical polymerisation of DTT monomer will be examined for comparison of the (opto)electronic behaviours in bulk and film in addition to investigations related to the chemical and electrochemical redox properties of those DTT based CMPs. Along with the preparation of novel electron donor systems, this section will also contain discussions related to the mechanism of network formation for Sonogashira Hagihara cross coupling derived CMPs considering the influence of regarding reaction media and monomer ratios for. 2. Synthesis of functional polymer networks for light driven heterogeneous catalysis; In this part the incorporation of a frequently used photoinitiator compound for photopolymerisation process, namely thioxanthone, into different microporous polymer backbones via two different polycondensation reactions will be presented. Applications on heterogeneous sustainable initiation of photopolymerisations of methyl methacrylate and cyclohexene oxide either under artificial light source or sunlight will be introduced

Have Covalent Organic Framework Films Revealed Their Full Potential?

Porous organic polymers provide high accessible surface areas, which make them attractive for gas storage, separation, and catalysis. In addition to those classical usage areas, such compounds are particularly interesting for electronic applications since their high dimensional, electron-rich backbone provides advanced electronic and photophysical properties. However, their non-soluble nature is a challenge for their processability, especially in the case of film formation, hence their limited utilization in organic electronic devices so far. Nevertheless, there are several techniques presented in the literature to overcome that issue, most of which were on the crystalline porous organic polymers, namely covalent organic frameworks (COFs). In this perspective, the developments on COF film formation and prospects for the improvements are discussed with suggestions to further their performances in organic electronics