- Three-dimensional molecular donors combined with polymeric acceptors for high performance fullerene-free organic photovoltaic devices
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Non-fullerene acceptor based organic photovoltaic devices (OPVs) reported so far are inferior to those derived from fullerenes. This increases the speculation on whether donors need to be tailored for advancing non-fullerene OPVs. We explored herein two direct arylation-derived diketopyrrolopyrrole (DPP)-based three-dimensional (3D) donors that can deliver respectable power conversion efficiencies (PCEs) of 4.64% and 4.02% with polymeric acceptor N2200 blends, surpassing those obtained from PC71BM (3.56% and 3.22%, respectively). It is found that these 3D-shaped molecular donors can yield improved photo-to-current conversion and balanced charge transport when blending with the linear N2200 polymer. This finding suggests that engineering molecular geometry can be a promising approach for developing high-performance materials.
- Liu, Shi-Yong,Jung, Jae Woong,Li, Chang-Zhi,Huang, Jiang,Zhang, Jianyuan,Chen, Hongzheng,Jen, Alex K.-Y.
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- Fluorinated microporous organic polymers: Design and applications in CO2adsorption and conversion
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Fluorinated microporous organic polymers (F-MOPs) were designed, showing twice higher CO2adsorption capacity than corresponding non-fluorous MOPs. The incorporation of phenanthroline moieties into F-MOPs afforded them the ability to coordinate with Ag(I), and the resultant F-MOP-Ag(I) displayed high efficiency for the reaction of CO2with propargyl alcohols to form a-alkylidene cyclic carbonates at 25°C.
- Yang, Zhen-Zhen,Zhao, Yanfei,Zhang, Hongye,Yu, Bo,Ma, Zhishuang,Ji, Guipeng,Liu, Zhimin
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- All-Carbon-Linked Continuous Three-Dimensional Porous Aromatic Framework Films with Nanometer-Precise Controllable Thickness
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Inherently porous materials that are chemically and structurally robust are challenging to construct. Conventionally, dynamic chemistry is thought to be needed for the formation of uniform porous organic frameworks, but dynamic bonds can limit the stability of these materials. For this reason, all-carbon-linked frameworks are expected to exhibit higher stability performance than more traditional porous frameworks. However, the limited reversibility of carbon-carbon bond-forming reactions has restricted the exploration of these materials. In particular, the challenges associated with producing uniform thin films of all-carbon-linked frameworks has inhibited the study of these materials in applications where well-defined films are required. Here, we synthesize continuous and homogeneous films of two different all-carbon-linked three-dimensional porous aromatic frameworks with nanometer-precision thickness (PAF-1 and BCMP-2). This was accomplished by kinetically promoting surface reactivity while suppressing homogeneous nucleation. Through connection of the PAF film to a gold substrate via a self-assembled monolayer and use of flow conditions to continually introduce monomers, smooth and continuous PAF films can be grown with controlled thickness. This strategy allows traditional transition metal mediated carbon-carbon cross-coupling reactions to form porous, organic thin films. We expect that the chemical principles uncovered in this study will enable the synthesis of a variety of chemically and structurally diverse carbon-carbon-linked frameworks as high-quality films, which are inaccessible by conventional methods.
- B?rjesson, Karl,Evans, Austin M.,Ratsch, Martin,Yang, Yizhou,Ye, Chen,Zhang, Airui
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- Metalation of a Mesoporous Three-Dimensional Covalent Organic Framework
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Constructing metalated three-dimensional (3D) covalent organic frameworks is a challenging synthetic task. Herein, we report the synthesis and characterization of a highly porous (SABET = 5083 m2 g-1) 3D COF with a record low density (0.13 g cm-3) containing π-electron conjugated dehydrobenzoannulene (DBA) units. Metalation of DBA-3D-COF 1 with Ni to produce Ni-DBA-3D-COF results in a minimal reduction in the surface area (SABET = 4763 m2 g-1) of the material due to the incorporation of the metal within the cavity of the DBA units, and retention of crystallinity. Both 3D DBA-COFs also display great uptake capacities for ethane and ethylene gas.
- Baldwin, Luke A.,Crowe, Jonathan W.,Pyles, David A.,McGrier, Psaras L.
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- Thiazolothiazole-linked porous organic polymers
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Thiazolothiazole-linked porous organic polymers have been synthesized from a facile catalyst-free condensation reaction between aldehydes and dithiooxamide under solvothermal conditions. The resultant porous frameworks exhibit a highly selective uptake of CO2 over N2 under ambient conditions. This journal is
- Zhu, Xiang,Tian, Chengcheng,Jin, Tian,Wang, Jitong,Mahurin, Shannon M.,Mei, Wenwen,Xiong, Yan,Hu, Jun,Feng, Xinliang,Liu, Honglai,Dai, Sheng
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- Microporous polymer network films covalently bound to gold electrodes
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Covalent attachment of a microporous polymer network (MPN) on a gold surface is presented. A functional bromophenyl-based self-assembled monolayer (SAM) formed on the gold surface acts as co-monomer in the polymerisation of the MPN yielding homogeneous and robust coatings. Covalent binding of the films to the electrode is confirmed by SEIRAS measurements.
- Becker, Daniel,Heidary, Nina,Horch, Marius,Gernert, Ulrich,Zebger, Ingo,Schmidt, Johannes,Fischer, Anna,Thomas, Arne
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- Luminescent infinite coordination polymer materials from metal-terpyridine ligation
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A new class of infinite coordination polymers (CP) was synthesized using a tetrahedral tetrakis[4-(4′-phenyl-2,2′:6′,2′′- terpyridine)phenyl]methane ligand as an organic node to direct the three-dimensional growth of the network and MII (M = Zn, Fe, Ni, and Ru) ions as inorganic linkers, an approach that is the opposite of the metal-as-a-node strategy used in the construction of metal-organic frameworks (MOFs). The unusual rod-like morphology of the resulting microporous materials can be tuned via solvents and reaction conditions. The covalent entrapment of a [Ru(tpy)2]2+ moiety in the skeleton of the 3D-network enables the Ru-CP to exhibit room-temperature luminescence.
- Eryazici, Ibrahim,Farha, Omar K.,Compton, Owen C.,Stern, Charlotte,Hupp, Joseph T.,Nguyen, Sonbinh T.
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- A microporous hydrogen-bonded organic framework for highly selective C 2H2/C2H4 separation at ambient temperature
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The first microporous hydrogen-bonded organic framework with permanent porosity and exhibiting extraordinarily highly selective adsorptive separation of C2H2 and C2H4 at ambient temperature has been established.
- He, Yabing,Xiang, Shengchang,Chen, Banglin
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- Synthesis and fine-tuning the pore properties of a thiophene based porous organic framework by post-oxidation treatment
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Porous organic frameworks (POFs) are an important class of materials, which have attracted great interests in recent years. The post modification of porous organic frameworks provides an efficient way to fine tune the properties of POFs for specific applications. However, most of the post functionalization methods need harsh reaction conditions and specific reagents and lead to a notable pore width decrease, which hinder the pore accessibility. Herein, we designed and synthesized a thiophene based POF with high surface area and stability. A straightforward post-oxidation of thiophene based POFs by meta-chloroperbenzoic acid introduced sulfone groups as hydrogen bonding sites in the channel with a less effected pore width in a controllable manner. The hydrogen bond acceptor sulfone groups could promote the adsorption of ammonia and enhance the proton conductivity of phosphoric acid or imidazole infiltrated POFs. The proton conductivity of phosphoric acid doped oxidized thiophene based POFs is over 10-3 S cm-1 at 120 °C under anhydrous conditions, which could be a promising candidate for fuel cells.
- Liu, Yanze,Zuo, Yiming,Li, Shuai,Li, Jiani,Li, Li,Liu, Caixia,Ashraf, Shumalia,Li, Pengfei,Wang, Bo
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- Robust C-C bonded porous networks with chemically designed functionalities for improved CO2 capture from flue gas
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Effective carbon dioxide (CO2) capture requires solid, porous sorbents with chemically and thermally stable frameworks. Herein, we report two new carbon-carbon bonded porous networks that were synthesized through metal-free Knoevenagel nitrile-aldol condensation, namely the covalent organic polymer, COP-156 and 157. COP-156, due to high specific surface area (650 m2/g) and easily interchangeable nitrile groups, was modified post-synthetically into free amine- or amidoxime-containing networks. The modified COP-156-amine showed fast and increased CO2 uptake under simulated moist flue gas conditions compared to the starting network and usual industrial CO2 solvents, reaching up to 7.8 wt % uptake at 40°C.
- Thirion, Damien,Lee, Joo S.,?zdemir, Ercan,Yavuz, Cafer T.
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- Two-Photon Absorption Properties and Structures of BODIPY and Its Dyad, Triad and Tetrad
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A series consisting of a dyad, a triad and a tetrad containing either two, three and four BODIPY units, respectively, has been synthesized and fully characterized and compared to two mono-BODIPY analogs (used as references). The one- and two-photon photophysical properties have been measured and the X-ray structures of four of the BODIPY derivatives have been determined. In the 700–900 nm range, the two-photon absorption (TPA) cross sections range from 30 GM to 160 GM for these compounds.
- Yang, Jian,Rousselin, Yoann,Bucher, Léo,Desbois, Nicolas,Bolze, Frédéric,Xu, Hai-Jun,Gros, Claude P.
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- Preparation of a bispyridine based porous organic polymer as a new platform for Cu(ii) catalyst and its use in heterogeneous olefin epoxidation
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A new type of bispyridine (bpy) incorporated POP was prepared via a cobalt-catalyzed acetylene trimerization. Subsequent immobilization of CuCl2 gave POP-Cu(ii). This new heterogeneous catalyst displayed outstanding olefin oxidation activity compared to its homogeneous analogue, suggesting that the degradation of the homogeneous catalyst was successfully inhibited by site isolation.
- Yi, Jigyoung,Ahn, Hye Mi,Yoon, Jong Ho,Kim, Cheal,Lee, Suk Joong
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- Gold nanoparticles confined in imidazolium-based porous organic polymers to assemble a microfluidic reactor: Controllable growth and enhanced catalytic activity
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A synthetic strategy is developed to grow Au nanoparticles supported by imidazolium-based porous organic polymers (Au/IM-POPs) along the inner surface of a fused-silica microfluidic capillary. The thickness of the hybrid Au/IM-POP material layers can be tuned by changing the precursor concentration. A variety of imidazolium-based porous organic polymers are developed from tetrakis[4-(1-imidazolyl)phenyl]methane and bromo-functionalized linker molecules and fully characterized, which may be used to support Au nanoparticles. Additionally the IM-POPs and Au/IM-POPs show porosity and the ability to take up guest molecules. The capillary coated with Au/IM-POPs is further assembled to obtain a catalytic microfluidic reactor. The catalytic activity of Au nanoparticles supported by the porous imidazolium polymer is probed by using the reduction of nitrobenzene derivatives flowing through the microfluidic reactor. The catalytic microfluidic reactor demonstrates significantly enhanced turnover frequency magnitudes in comparison with the corresponding reactions under batch conditions.
- Fang, Haobin,Sun, Shujian,Liao, Peisen,Hu, Ya,Zhang, Jianyong
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- Molecular Vise Approach to Create Metal-Binding Sites in MOFs and Detection of Biomarkers
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We report a new approach to create metal-binding site in a series of metal–organic frameworks (MOFs), where tetratopic carboxylate linker, 4′,4′′,4′′′,4′′′′-methanetetrayltetrabiphenyl-4-carboxylic acid, is partially replaced by a tritopic carboxylate linker, tris(4-carboxybiphenyl)amine, in combination with monotopic linkers, formic acid, trifluoroacetic acid, benzoic acid, isonicotinic acid, 4-chlorobenzoic acid, and 4-nitrobenzoic acid, respectively. The distance between these paired-up linkers can be precisely controlled, ranging from 5.4 to 10.8 ?, where a variety of metals, Mg2+, Al3+, Cr3+, Mn2+, Fe3+, Co2+, Ni2+, Cu2+, Zn2+, Ag+, Cd2+ and Pb2+, can be placed in. The distribution of these metal-binding sites across a single crystal is visualized by 3D tomography of laser scanning confocal microscopy with a resolution of 10 nm. The binding affinity between the metal and its binding-site in MOF can be varied in a large range (observed binding constants, Kobs from 1.56×102 to 1.70×104 L mol?1), in aqueous solution. The fluorescence of these crystals can be used to detect biomarkers, such as cysteine, homocysteine and glutathione, with ultrahigh sensitivity and without the interference of urine, through the dissociation of metal ions from their binding sites.
- Wang, Yang,Liu, Qi,Zhang, Qin,Peng, Bosi,Deng, Hexiang
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- Synthesis of TEMPO radical decorated hollow porous aromatic frameworks for selective oxidation of alcohols
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A bottom-up approach was developed to prepare TEMPO radical decorated hollow aromatic frameworks (HPAF-TEMPO) by using TEMPO radical functionalized monomers and SiO2nanospheres as templates. The accessible inner layer, high density of TEMPO sites, and hybrid micro-/mesopores of the HPAF-TEMPO enable the aerobic oxidation of a broad range of alcohols with high efficiency and excellent selectivity.
- Shen, Yan-Ming,Xue, Yun,Yan, Mi,Mao, Hui-Ling,Cheng, Hu,Chen, Zhuo,Sui, Zhi-Wei,Zhu, Shao-Bin,Yu, Xiu-Jun,Zhuang, Jin-Liang
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- Porous 3D polymers for high pressure methane storage and carbon dioxide capture
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High surface area 3D polymers represent one of the most promising classes of porous materials because of their high gas uptake and stability to thermal and chemical degradation. A series of porous organic polymers with aromatic building units have been synthesized and compared to explore their high-pressure performance as adsorbents of gases of relevant importance for energy and the environment. Particular attention was paid to methane storage up to pressures as high as 180 bar at ambient temperature. Porous polymers were prepared starting from a wide choice of spatially expanded aromatic monomers: a systematic change in the number of rings, variable size and shape was taken under consideration. The high number of rings (up to 6), which act as multiple reactive sites and form a number of connections between the multi-dentate nodes, result in an extensive cross-linked framework. Condensation was obtained by two alternative synthetic routes, viz., Yamamoto cross-coupling and Friedel-Crafts alkylation reactions. The structural characteristics and high stability of the porous polymers, even to mechanical compression, were carefully determined by several methods, including 1D and 2D solid state NMR, FT IR and thermal analyses. The CH4 uptake in the porous polymers allowed an understanding of the incremental response to pressure, up to extremely high values, and the exploitation of the extensive pressure range to customize the gas adsorption/desorption cycles for storage and transportation. Owing to the notable presence of large mesopores and network flexibility, combined with high surface area, a remarkable gain at high pressure was achieved, ensuring a highly competitive uptake/delivery efficiency. At 180 bar, adsorption values up to 445 cm3 STP g-1 were measured for porous organic polymers such as carbazolyl- and triptycene-based materials. The benchmark of these materials PAF1 reaches the value of 916 cm3 STP g-1 of adsorbed CH4, exceeding the performance of most of the best performing MOFs, COFs and activated carbons. CO2 and N2 adsorption isotherms collected at room temperature enabled the assessment of the suitability of such polymer networks for CO2 selective separation and capture. In summary, the in-depth and extensive comparative screening within this class of materials up to high pressures provides the necessary parameters for further synthetic and applicative work.
- Bracco, Silvia,Piga, Daniele,Bassanetti, Irene,Perego, Jacopo,Comotti, Angiolina,Sozzani, Piero
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- Symmetry-guided synthesis of highly porous metal-organic frameworks with fluorite topology
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Two stable, non-interpenetrated MOFs, PCN-521 and PCN-523, were synthesized by a symmetry-guided strategy. Augmentation of the 4-connected nodes in the fluorite structure with a rigid tetrahedral ligand and substitution of the 8-connected nodes by the Zr/Hf clusters yielded MOFs with large octahedral interstitial cavities. They are the first examples of Zr/Hf MOFs with tetrahedral linkers. PCN-521 has the largest BET surface area (3411 m 2 g-1), pore size (20.5×20.5×37.4 A?) and void volume (78.5%) of MOFs formed from tetrahedral ligands. This work not only demonstrates a successful implementation of rational design of MOFs with desired topology, but also provides a systematic way of constructing non-interpenetrated MOFs with high porosity. Meet me at the symmetry gates: Using a symmetry-guided design strategy, two stable, non-interpenetrated MOFs, were synthesized by augmenting the fluorite topology with tetrahedral linkers, thus expanding the cavity size (see scheme) and giving the largest pore size of any MOF with tetrahedral ligands. Copyright
- Zhang, Muwei,Chen, Ying-Pin,Bosch, Mathieu,Gentle III, Thomas,Wang, Kecheng,Feng, Dawei,Wang, Zhiyong U.,Zhou, Hong-Cai
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- Identifying the Recognition Site for Selective Trapping of 99TcO4- in a Hydrolytically Stable and Radiation Resistant Cationic Metal-Organic Framework
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Effective and selective removal of 99TcO4- from aqueous solution is highly desirable for both waste partitioning and contamination remediation purposes in the modern nuclear fuel cycle, but is of significant challenge. We report here a hydrolytically stable and radiation-resistant cationic metal-organic framework (MOF), SCU-101, exhibiting extremely fast removal kinetics, exceptional distribution coefficient, and high sorption capacity toward TcO4-. More importantly, this material can selectively remove TcO4- in the presence of large excesses of NO3- and SO42-, as even 6000 times of SO42- in excess does not significantly affect the sorption of TcO4-. These superior features endow that SCU-101 is capable of effectively separating TcO4- from Hanford low-level waste melter off-gas scrubber simulant stream. The sorption mechanism is directly unraveled by the single crystal structure of TcO4--incorporated SCU-101, as the first reported crystal structure to display TcO4- trapped in a sorbent material. A recognition site for the accommodation of TcO4- is visualized and is consistent with the DFT analysis results, while no such site can be resolved for other anions.
- Zhu, Lin,Sheng, Daopeng,Xu, Chao,Dai, Xing,Silver, Mark A.,Li, Jie,Li, Peng,Wang, Yaxing,Wang, Yanlong,Chen, Lanhua,Xiao, Chengliang,Chen, Jing,Zhou, Ruhong,Zhang, Chao,Farha, Omar K.,Chai, Zhifang,Albrecht-Schmitt, Thomas E.,Wang, Shuao
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- Anhydrous proton conduction in porous organic networks
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Solid electrolyte separators within fuel cells enable efficient charge transport and prevent a mass bypass between the two half cells. Hydrated systems, like Nafion, reach unprecedented proton conductivities at ambient temperatures, but the demanding humidity management prevents their use beyond 80 °C, hence limiting the efficiency of current polymer-based systems. As such, water free and chemically inert, solid materials with excellent conductivities between 100 °C and 200 °C, are of high interest. A promising approach is the incorporation of heavier amphoteric molecules into micro- and mesoporous frameworks. Stronger host-guest interactions allow for higher temperatures, while still maintaining sufficient mobility and efficient transport pathways. Here, we present a systematic study investigating the influence of porosity, framework topology and dimensionality as well as framework functionality and charge carrier uptake on the proton conductivity for six porous organic networks (PONs) loaded with imidazole via gas phase adsorption. The resulting materials were thoroughly characterized by multinuclear NMR and IR spectroscopy and physisorption as well as powder X-ray diffraction and DSC experiments, revealing homogeneous distribution of the amphoteric guests within the pore structure. Electrochemical impedance spectroscopy up to 130 °C revealed remarkable conductivities of up to 10?3 S cm?1 under anhydrous conditions. We found 3D networks to favour high imidazole loading leading to high proton conductivities based on the Grotthuss mechanism. In contrast, 2D networks showed a lower guest molecule uptake and thus lower proton conductivities, which were governed by vehicle transport. Additional acid/base functionalities within the frameworks seem to have a negative effect on the proton conduction.
- Klumpen,Winterstein,Papastavrou,Senker
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- A microporous six-fold interpenetrated hydrogen-bonded organic framework for highly selective separation of C2H4/C2H6
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A unique six-fold interpenetrated hydrogen-bonded organic framework (HOF) has been developed, for the first time, for highly selective separation of C2H4/C2H6 at room temperature and normal pressure. This journal is
- Li, Peng,He, Yabing,Arman, Hadi D.,Krishna, Rajamani,Wang, Hailong,Weng, Linhong,Chen, Banglin
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- Syntheses and Crystal Structures of Two Cadmium Methanetetrabenzoates Featured by Open Framework and Infinite Layers
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Colorless single crystals of Cd2[μ8-MTB]·3H2O·DMF (1) were prepared in DMF/H2O solution [1: space group C2/c (no. 15) with a = 1821.30(6), b = 2175.08(6), c = 1269.87(4) pm, β = 129.684(1)°]. The connection between the methane-p-benzoate tetraanions (MTB4–) and the Cd2+ cations leads to a three-dimensional framework with channels extending along [110] and [110] with openings of 670 pm × 360 pm. The channel-like voids accommodate water molecules and N,N-dimethylformamide (DMF) molecules not bound to Cd2+. Colorless single crystals of [Cd4(2,2′-bipy)4(μ7-MTB)2]·7DMF (2) were prepared in DMF in the presence of 2,2′-bipyridine [2: space group P1 (no. 2) with a = 1224.84(4), b = 1418.85(5), c = 2033.49(4) pm, α = 85.831(2)°, β = 88.351(2)°, γ = 68.261(1)°]. The coordination of MTB4– to Cd2+ results in infinite layers parallel to (001). The layers, not connected by any hydrogen bonds, contain small openings of about 320 pm × 340 pm.
- Harms, Sven,K?ferstein, Roberto,G?rls, Helmar,Robl, Christian
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- Chiral porous organic frameworks for asymmetric heterogeneous catalysis and gas chromatographic separation
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Three chiral robust diene-based porous organic frameworks (POFs) are prepared. POF-1 is shown to be an efficient heterogeneous catalyst after metallation for asymmetric conjugation addition with up to 93% ee, and it can also function as a new chiral stationary phase for gas chromatographic separation of racemates. This journal is
- Dong, Jinqiao,Liu, Yan,Cui, Yong
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- Introduction of π-complexation into porous aromatic framework for highly selective adsorption of ethylene over ethane
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In this work, we demonstrate for the first time the introduction of π-complexation into a porous aromatic framework (PAF), affording significant increase in ethylene uptake capacity, as illustrated in the context of Ag(I) ion functionalized PAF-1, PAF-1-SO3Ag. IAST calculations using single-component-isotherm data and an equimolar ethylene/ethane ratio at 296 K reveal that PAF-1-SO3Ag shows exceptionally high ethylene/ethane adsorption selectivity (Sads: 27 to 125), far surpassing benchmark zeolite and any other MOF reported in literature. The formation of π-complexation between ethylene molecules and Ag(I) ions in PAF-1-SO 3Ag has been evidenced by the high isosteric heats of adsorption of C2H4 and also proved by in situ IR spectroscopy studies. Transient breakthrough experiments, supported by simulations, indicate the feasibility of PAF-1-SO3Ag for producing 99.95%+ pure C 2H4 in a Pressure Swing Adsorption operation. Our work herein thus suggests a new perspective to functionalizing PAFs and other types of advanced porous materials for highly selective adsorption of ethylene over ethane.
- Li, Baiyan,Zhang, Yiming,Krishna, Rajamani,Yao, Kexin,Han, Yu,Wu, Zili,Ma, Dingxuan,Shi, Zhan,Pham, Tony,Space, Brian,Liu, Jian,Thallapally, Praveen K.,Liu, Jun,Chrzanowski, Matthew,Ma, Shengqian
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- Facile synthesis of azo-linked porous organic frameworks via reductive homocoupling for selective CO2 capture
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A facile Zn-induced reductive homocoupling reaction was used to synthesize azo-linked porous organic frameworks (azo-POFs) from easily accessed nitro monomers. Azo-POF-2 exhibits the highest CO2/N2 selectivity of 76 at 273 K among all self-coupled azo-linked porous polymers. This journal is the Partner Organisations 2014.
- Lu, Jingzhi,Zhang, Jian
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- Rigid Multidimensional Alkoxyamines: A Versatile Building Block Library
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Since the discovery of the “living” free-radical polymerization, alkoxyamines were widely used in nitroxide-mediated polymerization (NMP). Most of the known alkoxyamines bear just one functionality with only a few exceptions bearing two or more alkoxyamine units. Herein, we present a library of novel multidimensional alkoxyamines based on commercially available, rigid, aromatic core structures. A versatile approach allows the introduction of different sidechains which have an impact on the steric hindrance and dissociation behavior of the alkoxyamines. The reaction to the alkoxyamines was optimized by implementing a mild and reliable procedure to give all target compounds in high yields. Utilization of biphenyl, p-terphenyl, 1,3,5-triphenylbenzene, tetraphenylethylene, and tetraphenyl-methane results in linear, trigonal, square planar, and tetrahedral shaped alkoxyamines. These building blocks are useful initiators for multifold NMP leading to star-shaped polymers or as a linker for the nitroxide exchange reaction (NER), to obtain dynamic frameworks with a tunable crosslinking degree and self-healing abilities.
- Matt, Yannick,Wessely, Isabelle,Gramespacher, Lisa,Tsotsalas, Manuel,Br?se, Stefan
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supporting information
p. 239 - 245
(2020/12/17)
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- Preparation of Recyclable and Versatile Porous Poly(aryl thioether)s by Reversible Pd-Catalyzed C–S/C–S Metathesis
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Porous organic materials (polymers and COFs) have shown a number of promising properties; however, the lability of their linkages often limits their robustness and can hamper downstream industrial application. Inspired by the outstanding chemical, mechanical, and thermal resistance of the 1D polymer poly(phenylene sulfide) (PPS), we have designed a new family of porous poly(aryl thioether)s, synthesized via a mild Pd-catalyzed C–S/C–S metathesis-based method, that merges the attractive features common to porous polymers and PPS in a single material. In addition, the method is highly modular, allowing to easily introduce application-oriented functionalities in the materials for a series of environmentally relevant applications including metal capture, metal sensing, and heterogeneous catalysis. Moreover, despite their extreme chemical resistance, the polymers can be easily recycled to recover the original monomers, offering an attractive perspective for their sustainable use. In a broader context, these results clearly demonstrate the untapped potential of emerging single-bond metathesis reactions in the preparation of new, recyclable materials.
- Morandi, Bill,Rivero-Crespo, Miguel A.,Toupalas, Georgios
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supporting information
p. 21331 - 21339
(2021/12/17)
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- Unusual Metal-Organic Framework Topology and Radiation Resistance through Neptunyl Coordination Chemistry
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A Np(V) neptunyl metal-organic framework (MOF) with rod-shaped secondary building units was synthesized, characterized, and irradiated with γrays. Single-crystal X-ray diffraction data revealed an anionic framework containing infinite helical chains of actinyl-actinyl interaction (AAI)-connected neptunyl ions linked together through tetratopic tetrahedral organic ligands (NSM). NSM exhibits an unprecedented net, demonstrating that AAIs may be exploited to give new MOFs and new topologies. To probe its radiation stability, we undertook the first irradiation study of a transuranic MOF and its organic linker building block using high doses of γrays. Diffraction and spectroscopic data demonstrated that the radiation resistance of NSM is greater than that of its linker building block alone. Approximately 6 MGy of irradiation begins to induce notable changes in the long- and short-range order of the framework, whereas 3 MGy of irradiation induces total X-ray amorphization and changes in the local vibrational bands of the linker building block.
- Burns, Peter C.,Chen, Zhijie,Fairley, Melissa,Farha, Omar K.,Gilson, Sara E.,Hanna, Sylvia L.,Julien, Patrick,Laverne, Jay A.,Szymanowski, Jennifer E. S.
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supporting information
p. 17354 - 17359
(2021/11/04)
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- Remarkable Structural Diversity between Zr/Hf and Rare-Earth MOFs via Ligand Functionalization and the Discovery of Unique (4, 8)-c and (4, 12)-connected Frameworks
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Ligand modification in MOFs provides great opportunities not only for the development of functional materials with new or enhanced properties but also for the discovery of novel structures. We report here that a sulfone-functionalized tetrahedral carboxylate-based ligand is capable of directing the formation of new and fascinating MOFs when combined with Zr4+/Hf4+ and rare-earth metal cations (RE) with improved gas-sorption properties. In particular, the resulting M-flu-SO2 (M: Zr, Hf) materials display a new type of the augmented flu-a net, which is different as compared to the flu-a framework formed by the nonfunctionalized tetrahedral ligand. In terms of properties, a remarkable increase in the CO2 uptake is observed that reaches 76.6% and 61.6% at 273 and 298 K and 1 bar, respectively. When combined with REs, the sulfone-modified linker affords novel MOFs, RE-hpt-MOF-1 (RE: Y3+, Ho3+, Er3+), which displays a fascinating (4, 12)-coordinated hpt net, based on nonanuclear [RE9(μ3-?)2(μ3-??-)12(-COO)12] clusters that serve as hexagonal prismatic building blocks. In the absence of the sulfone groups, we discovered that the tetrahedral linker directs the formation of new RE-MOFs, RE-ken-MOF-1 (RE: Y3+, Ho3+, Er3+, Yb3+), that display an unprecedented (4, 8)-coordinated ken net based on nonanuclear RE9-clusters, to serve as bicapped trigonal prismatic building units. Successful activation of the representative member Y-ken-MOF-1 reveals a high BET surface area and total pore volume reaching 2621 m2 g-1 and 0.95 cm3 g-1, respectively. These values are the highest among all RE MOFs based on nonanuclear clusters and some of the highest in the entire RE family of MOFs. The present work uncovers a unique structural diversity existing between Zr/Hf and RE-based MOFs that demonstrates the crucial role of linker design. In addition, the discovery of the new RE-hpt-MOF-1 and RE-ken-MOF-1 families of MOFs highlights the great opportunities existing in RE-MOFs in terms of structural diversity that could lead to novel materials with new properties.
- Angeli, Giasemi K.,Batzavali, Danai,Mavronasou, Katerina,Tsangarakis, Constantinos,Stuerzer, Tobias,Ott, Holger,Trikalitis, Pantelis N.
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supporting information
p. 15986 - 15994
(2020/10/18)
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- Fluorinated porous organic frameworks for improved CO2 and CH4 capture
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A porous 3D selectively fluorinated framework (F-PAF1), robust yet flexible and with a surface area of 2050 m2 g-1, was synthesised by condensation of an ad hoc prepared fluorinated tetraphenylmethane (TPM) monomer to ensure homogenously distributed C-F dipoles in the swellable architecture. Tetradentate TPM was also the comonomer for the reaction with fluorinated difunctional monomers to obtain frameworks (FMFs) with a controlled amount of regularly spaced reorientable C-F dipoles. The isosteric heat of adsorption of CO2 was increased by 53% by even moderate C-F dipole insertion, with respect to the non-fluorinated frameworks. CO2/N2 selectivity was also increased up to a value of 50 for the difluoro-containing comonomer. Moreover, methane shows optimal interaction energies of 24 kJ mol-1.
- Comotti,Castiglioni,Bracco,Perego,Pedrini,Negroni,Sozzani
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supporting information
p. 8999 - 9002
(2019/07/31)
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- Methane-perylene diimide-based small molecule acceptors for high efficiency non-fullerene organic solar cells
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We report perylene diimide (PDI) small molecules based on diphenylmethane, triphenylmethane, and tetraphenylmethane cores, named PM-PDI2, PM-PDI3 and PM-PDI4, respectively. The OSC performances of PM-PDI3 and PM-PDI4 are comparable. The PM-PDI3 based device with PDBT-T1 as the donor achieved a highest power conversion efficiency (PCE) of 7.58% along with a high open-circuit voltage (VOC) of 0.98 V, a short-circuit current density (JSC) of 11.02 mA cm-2 and a high fill factor (FF) of 69.9%, a 1.32 times boost in PCE with respect to the PM-PDI2 based control device (3.26%). The high photovoltaic performance of the PM-PDI3 based device can be attributed to its relatively high-lying LUMO level, complementary absorption spectra with the polymer donor material PDBT-T1, relatively favorable morphology and improved exciton dissociation and charge collection efficiency. A PCE of 7.58% is among the highest efficiency of phenyl-methane as core based non-fullerene organic solar cells. Overall, this work provides a new approach to enhance the performance of non-fullerene acceptors.
- Li, Gang,Yang, Wenbin,Wang, Shuaihua,Liu, Tao,Yan, Cenqi,Zhang, Yu,Li, Dandan,Wang, Xinyu,Hao, Pin,Li, Jiewei,Huo, Lijun,Yan, He,Tang, Bo
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supporting information
p. 10901 - 10907
(2019/09/19)
-
- Diamondoid architectures from halogen-bonded halides
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The reactions between a tetrahedrally-shaped tecton, tetrakis(4-(iodoethynyl)phenyl)methane, and tetraphenylphosphonium halides readily afford interpenetrated and densely packed diamondoid architectures sustained by C-I?X- (X- = chloride, bromide, iodide) interactions. In all these halogen-bonded networks, the halide anions act as four-connecting nodes, while the tetraphenylphosphonium cations provide essential templating information and structural support.
- Gunawardana,Dakovi?,Aaker?y
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supporting information
p. 607 - 610
(2018/02/06)
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- METHOD AND COMPOUND
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A method of forming a layer of an electronic device, for example an organic light-emitting device, the method comprising the step of depositing a precursor layer comprising a compound of formula (I) and reacting the compound of formula (I) in a ring-opening addition reaction: Core-(Reactive Group)n (I) wherein Core is a non-polymeric core group; and each Reactive Group, which may be the same or different in each occurrence, is a group of formula (II): wherein Sp1 independently in each occurrence represents a spacer group; w independently in each occurrence is 0 or 1; Ar in each occurrence independently represents an aryl or heteroaryl group; R1 in each occurrence independently represents H or a substituent, with the proviso that at least one R1 is a substituent; n is at least 1; and* is a point of attachment of the group of formula (II) to the Core; and wherein the compound of formula (I) reacts with itself or with a non-polymeric co-reactant.
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Page/Page column 30
(2020/12/15)
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- Tetraphenyl carbon-based OLED main body material and application thereof in preparation of OLED device
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The invention provides a tetraphenyl carbon-based OLED main body material and application thereof in preparation of an OLED device. The structural formula of the compound of the main body material isshown in the specification, wherein n of the four substituent groups R1, R2, R3 and R4 are the same electron donor groups, and 4-n of the four substituent groups R1, R2, R3 and R4 are same electron absorber groups; n is greater than or equal to 0 and less than or equal to 4. The tetraphenyl carbon-based OLED main body material provided in the invention can be used for preparing the OLED device through a solution process. The tetraphenyl carbon-based OLED main body material provided by the invention has controllable HOMO and LUMO energy levels to implement that a current carrier injects a luminous layer from an electrode or from a low-energy barrier or an energy-free barrier of a transmission layer of the current carrier, has singlet-state and triplet-state energy levels greater than 3.0 eVto effectively prevent the reduction of the performance of the device caused by the fact that an exciton is transmitted back from a luminous material to the main body material and improve the efficiency of the OLED device, and has a controllable hole and electron transmission rate to implement balance between electron transmission and hole transmission in the luminous layer and expand an excitoncombination region and a luminous region to reduce the roll-off of the efficiency of the OLED device.
- -
-
Paragraph 0022; 0023; 0024; 0030
(2018/11/22)
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- Water mediated proton conduction in a sulfonated microporous organic polymer
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Polymer membranes (PEMs) within fuel cells (FCs) act as separators and efficient proton conducting electrolytes. Established systems tend to microphase separation into hydrophilic and hydrophobic regions, making these materials prone to water loss at elevated temperatures. Therefore, recent approaches utilize porous materials, which promise stronger interactions between water molecules and the framework, while still providing efficient conductive pathways. Here we show, that the microporous polymer PAF-1 exhibits proton conductivities up to 10-1 S cm-1 under hydrous conditions, after post-synthetic sulfonation. Gas phase sulfonation turned out to be the essential step for introducing a sufficiently large amount of -SO3H groups and thus a high charge carrier concentration upon hydration. While the absolute conductivity of the sulfonated frameworks strongly depends on the water uptake, we found similar activation barriers for all relative humidities. Since water is homogeneously stored in micro- and mesoporous voids, the activation barrier of the interpore conductivity is decisive for the macroscopic properties.
- Klumpen,G?drich,Papastavrou,Senker
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supporting information
p. 7592 - 7595
(2017/07/12)
-
- Room-Temperature Activation of Hydrogen by Semi-immobilized Frustrated Lewis Pairs in Microporous Polymer Networks
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Porous polymer networks based on sterically encumbered triphenylphosphine motifs, mimicking the basic sites employed in frustrated Lewis pair (FLP) chemistry, were synthesized via Yamamoto polymerization and their interactions with the strong Lewis acid B(C6F5)3 probed. The combinations yield semi-immobilized FLPs, which are able to cleave dihydrogen heterolytically at ambient temperature and low hydrogen pressure.
- Trunk, Matthias,Teichert, Johannes F.,Thomas, Arne
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supporting information
p. 3615 - 3618
(2017/03/20)
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- Microporous organic polymers involving thiadiazolopyridine for high and selective uptake of greenhouse gases at low pressure
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A new core of [1,2,5]-thiadiazolo-[3,4-c]-pyridine was employed for the fabrication of microporous organic polymers exhibiting a very high CO2 uptake of 5.8 mmol g-1 (25.5 wt%) at 273 K and 1 bar. The presence of CO2-philic active sites and microporosity confer the high uptake and superior selectivity (61) towards CO2 over N2.
- Waseem Hussain, Md.,Bandyopadhyay, Sujoy,Patra, Abhijit
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supporting information
p. 10576 - 10579
(2017/09/29)
-
- Functionalized Porous Organic Polymers for Olefin/Paraffin Separations
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Compositions containing a porous organic polymer and a monovalent metal cation are provided for separation/purification of olefins and paraffins. The compositions can be stable and recyclable. The compositions can contain acidic functional group having monovalent metal cations associated therein. The monovalent metal cations can include Ag(I) and Cu(I), capable of strong cation-pi binding to ethylene and other olefins. The compositions can have a large surface area greater than about 20 m2/g. The compositions can be used to separate/purify mixtures of ethylene and ethane. The compositions can have an ethylene/ethane adsorption selectivity of about 20 to 500 at 296 K. Methods of making the compositions are provided. Methods can include synthesizing the porous organic polymer, grafting acidic functional groups onto the polymer, and cation exchange with a salt or acid of a monovalent metal cation. Methods of olefin/paraffin separation are provided capable of achieving purities over 99%.
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Page/Page column
(2015/07/15)
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- Tetrahedral rigid core antenna chromophores bearing bay-substituted perylenediimides
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Two new representative methane- and adamantane-centered 'antenna' tetramers bearing bay-substituted π-conjugated phenylethynyl-perylenediimides (PDICCPh) as chromophoric subunits, tetrakis-[1-(4-ethynylphenyl)-N,N′-bis(1-hexylheptyl)-perylene-3,4:9,10-tetracarboxylic diimide]-methane (1) and tetrakis-1,3,5,7-[1-(4-ethynylphenyl)-N,N′-bis(1-hexylheptyl)-perylene-3,4:9,10-tetracarboxylic diimide]-adamantane (2), have been synthesized and their structural aspects have been thoroughly investigated by NMR spectroscopy. These PDI tetramers (1 and 2) represent the first successful example of incorporating the bay-substituted phenylethynyl-perylenediimides into the large rigid core tetrahedral frameworks. In these PDI tetramers, dynamic NMR experiments revealed the existence of perylene-centered conformational dynamic equilibrium (ΔG≠=15-17 kcal/mol), the primary cause of the observed spectral broadening in conventional 1H NMR spectra (295 K). In addition, PDI tetramers 1 and 2 were found to possess exceptional (photo)chemical stability, and their corresponding photophysical properties (εmax~180,000; τFL=6.9 ns; ΦFL~60%) make them viable candidates for various photonic applications and are in good agreement with other related multichromophoric PDI-based systems.
- Myahkostupov, Mykhaylo,Castellano, Felix N.
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p. 9519 - 9527
(2015/12/01)
-
- Dendrimer-type peptoid-decorated hexaphenylxylenes and tetraphenylmethanes: Synthesis and structure in solution and in the gas phase
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Branched organic nanostructures are useful scaffolds that find multiple applications in a variety of fields. Here, we present a novel approach to dendrimer-like structures. Our design contains a rigid hydrocarbon-based core (hexaphenylxylylene/tetraethynylphenylmethane) combined with a library of N-substituted oligoglycines (so-called peptoids) providing a flexible shell. The use of click chemistry allows rapid assembly of the nanostructures. The possibility of tuning the size and the solubility of this new type of nanostructure will be advantageous for future applications such as heterogeneous catalysis.
- Peschko, Katharina,Schade, Alexandra,Vollrath, Sidonie B.L.,Schwarz, Ulrike,Luy, Burkhard,Muhle-Goll, Claudia,Weis, Patrick,Br?se, Stefan
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p. 16273 - 16278
(2015/01/09)
-
- Three-dimensional supramolecular polymers driven by rigid tetrahedral building blocks through tetrathiafulvalene radical cation dimerization
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Rigid tetrahedral compounds T1 and T2 that bear four tetrathiafulvalene (TTF) units, which are connected to a tetraphenylmethane core by the ethynylene or amide linker were designed and prepared. Upon one-electron oxidation of the TTF units by Fe(ClO4)3, the resulting TTF+ radical cations stacked intermolecularly to give rise to three-dimensional supramolecular polymers, which were supported by UV-vis spectroscopy, cyclic voltammetry, dynamic light scattering, and scanning electron microscopy.
- Chen, Lan,Zhang, Shao-Chen,Wang, Hui,Zhou, Ya-Ming,Li, Zhan-Ting,Zhang, Dan-Wei
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p. 4778 - 4783
(2014/06/24)
-
- Central-atom size effects on the methyl torsions of group XIV tetratolyls
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The Group XIV tetratolyl series X(C6H4-CH 3)4 (X=C, Si, Ge, Sn, Pb) were studied by using inelastic neutron scattering to measure the low-energy phonon spectra to directly access the methyl-group torsional modes. The effect of increased molecular radius as a function of the size of the central atom was shown to have direct influence on the methyl dynamics, reinforced with the findings of molecular dynamics and contact surface calculations, based upon the solid-state structures. The torsional modes in the lightest analogue were found to be predominantly intramolecular: the Si and Ge analogues have a high degree of intermolecular methyl-methyl group interactions, whilst the heaviest analogues (Sn and Pb) showed pronounced intermolecular methyl interactions with the whole phonon bath of the lattice modes. Size matters! The size of the central atom in the Group XIV tetratolyls was shown to determine the solid-state structures courtesy of the effect that it has on the overall size of the molecules (see figure). Because the outer-most methyl groups enter into close intermolecular interactions (for the Si and Ge analogues), the structure is driven to lower symmetry; as a consequence, the smallest (C) and largest (Sn and Pb) analogues are isostructural. Copyright
- Ng, Maggie C. C.,Harper, Jason B.,Stampfl, Anton P. J.,Kearley, Gordon J.,Rols, Stephane,Stride, John A.
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supporting information
p. 13018 - 13024
(2013/01/15)
-
- A "click-based" porous organic polymer from tetrahedral building blocks
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A thermally and chemically stable "click-based" porous organic polymer with high surface area was synthesized from two tetrahedral building blocks.
- Pandey, Prativa,Farha, Omar K.,Spokoyny, Alexander M.,Mirkin, Chad A.,Kanatzidis, Mercouri G.,Hupp, Joseph T.,Nguyen, Sonbinh T.
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supporting information; experimental part
p. 1700 - 1703
(2011/10/01)
-
- Quantum interference distinguishes between constitutional isomers
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Matter waves, as introduced by de Broglie in 1923 (L. de Broglie, Nature, 1923, 112, 540),1 are a fundamental quantum phenomenon, describing the delocalized center of mass motion of massive bodies and we show here their sensitivity to the molecular structure of constitutional isomers.
- Tuexen, Jens,Gerlich, Stefan,Eibenberger, Sandra,Arndt, Markus,Mayor, Marcel
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supporting information; scheme or table
p. 4145 - 4147
(2010/09/04)
-
- The central atom size effect on the structure of group 14 tetratolyls
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The tetraphenyl derivatives of the Group 14 elements are of great potential interest as supramolecular constructs in extended porous networks. The tetratolyl Group 14 compounds were synthesized by using a general reaction scheme involving the nucleophilic addition of an organometallic reagent to the electrophilic center of the Group 14 element. The tetrachloride derivatives were used for the synthesis of the silane, germane and stannane compounds. Sn(Tol)4 was found to have tunnel splittings much smaller than the minimum line width available on IN16, whereas the lighter analogues displayed a remarkable size effect of the central atom. The tunneling peaks were observed to persist up to around 30 K, before softening and extending into the limit of quasielastic diffusion in which the rotors undergo thermally excited rotation.
- Ng, Maggie C. C.,Craig, Donald J.,Harper, Jason B.,Van-Eijck, Lambert,Stride, John A.
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supporting information; experimental part
p. 6569 - 6572
(2010/02/28)
-
- Four-fold click reactions: Generation of tetrahedral methane- and adamantane-based building blocks for higher-order molecular assemblies
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A modular concept for the generation of achiral and chiral non-racemic tetrahedral tectons from common precursors was developed. The tectons presented here are based on tetraphenylmethane or 1,3,5,7-tetraphenyladamantane core structures. They are obtained through high-yielding four-fold click reactions, using either the tetraazido or the tetraalkyne precursors. In most cases, the tetratriazoles are obtained as pure products after simple washing with water and methanol. The side chains of the tectons prepared include a self-complementary DNA dimer, obtained from a 3′-azidonucleoside and a phosphoramidite. The concept allows for a variation of the "sticky ends", leading to tecton or ligand libraries.
- Plietzsch, Oliver,Schilling, Christine Inge,Tolev, Mariyan,Nieger, Martin,Richert, Clemens,Muller, Thierry,Braese, Stefan
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supporting information; experimental part
p. 4734 - 4743
(2009/12/08)
-
- 'Click' Dendritic phosphines: Design, synthesis, application in Suzuki coupling, and recycling by nanofiltration
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A new synthetic route towards stable molecular-weight enlarged monodentate phosphine ligands via 'click' chemistry was developed. These ligands were applied in the Pd-catalyzed Suzuki-Miyaura coupling of aryl halides and phenyl boronic acid. The supported systems show very similar activities compared to the unsupported analogues. Moreover, recycling experiments by means of nanofiltration using ceramic nanofiltration membranes demonstrate that these systems can be recovered and reused efficiently.
- Janssen, Michele,Mueller, Christian,Vogt, Dieter
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supporting information; body text
p. 313 - 318
(2009/10/20)
-
- Structure and charge control in metal-organic frameworks based on the tetrahedral ligand tetrakis(4-tetrazolylphenyl)methane
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Use of the tetrahedral ligand tetrakis(4-tetrazolylphenyl)methane enabled isolation of two three-dimensional metal-organic frameworks featuring 4,6- and 4,8-connected nets related to the structures of garnet and fluorite with the formulae Mn6(ttpm)3·5DMF·3H20 (1) and Cu[(Cu4Cl)(ttpm)2]2·CuCl 2·5 DMF·11H2O (2) (H4ttpm = tetrakis(4-tetrazolylphenyl)methane). The fluorite-type solid 2 displays an unprecedented post-synthetic transformation in which the negative charge of the framework is reduced by extraction of copper(II) chloride. Desolvation of this compound generates Cu4(ttpm)2·0.7 CuCl2 (2d), a microporous material exhibiting a high surface area and significant hydrogen uptake.
- Dinca, Mircea,Dailly, Anne,Long, Jeffrey R.
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supporting information; scheme or table
p. 10280 - 10285
(2009/10/16)
-
- Synthesis and Isolation of Polytrityl Cations by Utilizing Hexaphenylbenzene and Tetraphenylmethane Scaffolds
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The successful isolation of stable (and soluble) hexa- and tetratrityl cations based on hexaphenyl-benzene and tetraphenylmethane scaffold has been accomplished by using readily available starting materials. These robust polytrityl cations can be isolated in crystalline form and stored indefinitely at 0 °C. Their structures have been established by 1H/ 13C NMR spectroscopy and by UV-vis spectroscopy. The structures of these polytrityl cations were further confirmed by quantitative transformations to the reduced (poly)triphenylmethyl derivatives by hydride transfer from triethylsilane, cycloheptatriene, or a borane-dimethyl sulfide complex.
- Rathore, Rajendra,Burns, Carrie L.,Guzei, Ilia A.
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p. 1524 - 1530
(2007/10/03)
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- Multiple-electron transfer in a single step. Design and synthesis of highly charged cation-radical salts
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(equation presented) Macromolecules 1c and 2c bearing multiple redox-active sites are synthesized by an efficient palladium-catalyzed coupling of 2,5-dimethoxytolylmagnesium bromide with readily available hexakis(4-bromophenyl)benzene and tetrakis(4-bromophenyl)methane. These macromolecular electron donors undergo reversible oxidation at a constant potential of 1.15 V vs SCE to yield robust, multiply charged cation radicals that are isolated in pure form using SbCl5 as an oxidant. These nanometer-size cation-radical salts are shown to act as efficient "electron sponges" toward a variety of electron donors.
- Rathore, Rajendra,Burns, Carrie L.,Deselnicu, Mihaela I.
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p. 2887 - 2890
(2007/10/03)
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- Design and construction of a new class of scaffolding-like materials comprising infinite polymeric frameworks of 3D-linked molecular rods. A reappraisal of the Zn(CN)2 and Cd(CN)2 structures and the synthesis and structure of the diamond-related frameworks [N(CH3)4] [CuIZnIIKCN4]
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It is proposed that a new and potentially extensive class of scaffolding-like materials may be afforded by linking together centers with either a tetrahedral or an octahedral array of valences by rodlike connecting units. Some simple general principles concerning the design and construction of these frameworks are presented together with reasons for expecting them to show unusual and useful properties. Two of the simplest conceivable systems of this type are isomorphous Zn(CN)2 and Cd(CN)2 whose structures have been reexamined by single-crystal X-ray diffraction, confirming the earlier description based on powder diffraction data of two interpenetrating diamond-related frameworks: cubic with space group P43m, Z = 2; a = 5.9002 (9) ? (Zn(CN)2) and 6.301 (1) ? (Cd(CN)2); two unique metal centers, one surrounded tetrahedrally by 4 C and the other by 4 N donors; MCNM rods linear; ZnC, 1.923 (6) ?; ZnN, 2.037 (5) ?; CdC, 2.099 (5) ?; CdN, 2.196 (4) ?; CN, 1.150 (5) A in Zn(CN)2 and 1.162 (5) A in Cd(CN)2. The interpenetration of separate frameworks demonstrated in these archetypal structures is likely to be a major concern in future studies of more complex scaffolding materials. The material [N(CH3)4][CuZn(CN)4] was deliberately designed to demonstrate one conceivable way of preventing interpenetration; its structure was determined by single-crystal X-ray diffraction: cubic, F43m, a = 11.609 (3) ?, Z = 4. The structure contains a single diamond-related framework with alternating tetrahedral Cu(I) and Zn(II) centers and linear rods that are very likely of the type CuCNZn with bond distances CuC, 1.877 (8) ?; and ZnN, 2.069 (15) ?. N(CH3)4+ ions occupy half the adamantane cavities generated by the framework, the remaining cavities being vacant. Cu I[4,4′,4″,4?-tetracyanotetraphenylmethane]-BF 4·XC6H5NO2 (x ≥ 7.7) represents the first attempt to generate an infinite 3D framework with rods of some complexity. The structure was determined by single-crystal X-ray diffraction; tetragonal, I4m2, a = 13.620 (2) ?, c = 22.642 (2) ?, Z = 2. The structure contains a diamond-related cationic framework with C·C6H4·CN·Cu rods of length 8.856 (2) ?. The framework is tetragonally elongated along the c axis apparently as a result of nonbonded interactions between the eight ortho-hydrogen atoms around the methane carbon centers. There is no interpenetration. The framework generates very large admanantane-like cavities occupied by disordered C6H5NO2 (at least 7.7 molecules per Cu) together with BF4- ions. The crystals undergo ready anion exchange. The material is unusual in that approximately two-thirds by volume of what is undoubtedly a crystal is effectively liquid. The results provide confidence that a wide range of scaffolding-like solids should prove accessible.
- Hoskins,Robson
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p. 1546 - 1554
(2007/10/02)
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