The key parameters of conjugated polymers are lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) energy levels. Few approaches can simultaneously lower LUMO and ...HOMO energy levels of conjugated polymers to a large extent (>0.5 eV). Disclosed herein is a novel strategy to decrease both LUMO and HOMO energy levels of conjugated polymers by about 0.6 eV through replacement of a CC unit by a B←N unit. The replacement makes the resulting polymer transform from an electron donor into an electron acceptor, and is proven by fluorescence quenching experiments and the photovoltaic response. This work not only provides an effective approach to tune the LUMO/HOMO energy levels of conjugated polymers, but also uses organic boron chemistry as a new toolbox to develop conjugated polymers with high electron affinity for polymer optoelectronic devices.
Transforming units: A novel strategy decreases both LUMO and HOMO energy levels of conjugated polymers, by about 0.6 eV, through replacement of a CC unit by a B←N unit. The replacement transforms the resulting polymer from an electron donor into an electron acceptor.
Carbon dots (CDs) have attracted attention in metal‐free afterglow materials, but most CDs were heteroatom‐containing and the afterglow emissions are still limited to the short‐wavelength region. A ...universal approach to activate the room‐temperature phosphorescence (RTP) of both heteroatom‐free and heteroatom‐containing CDs was developed by one‐step heat treatment of CDs and boric acid (BA). The introduction of an electron‐withdrawing boron atom in composites can greatly reduce the energy gap between the singlet and triplet state; the formed glassy state can effectively protect the excited triplet states of CDs from nonradiative deactivation. A universal host for embedding CDs to achieve long‐lifetime and multi‐color (blue, green, green‐yellow and orange) RTP via a low cost, quick and facile process was developed. Based on their distinctive RTP performances, the applications of these CD‐based RTP materials in information encryption and decryption are also proposed and demonstrated.
The room‐temperature phosphorescence (RTP) of CDs was activated by one‐step heat treatment of CDs and boric acid (BA). Heteroatom‐free CDs (a‐CDs) possess favorable RTP in BA matrix with a lifetime as high as 1.6 s. Blue, green, yellow‐green, and orange RTP CD‐based materials were obtained. These CD‐based RTP materials were successfully applied in information encryption owing to their distinctive RTP performance.
The Bor metallogenic zone is one of the most important metallogenic units in the Republic of Serbia. Volcanic processes in this unit are characterized by the domination of extrusive volcanic ...activity, and the change of depositional environment during the numerous volcanic cycles, as well as facial transitions and huge deposition of syn- and post eruptive resedimented volcanoclastics. The predominant metals in the Bor metallogenic zone are copper and gold, accompanied by iron, base-metals, silver, molybdenum, and minor platinum-group elements. The most prominent morphogenetic types of deposit comprise porphyry copper-gold, cupriferous pyrite, massive base-metal sulphides and hydrothermal veins, iron oxides skarns, carbonate replacement polymetallic deposits, volcanogenic epithermal gold mineralization of the high sulphidation type, and exceptionally rare clasts of copper sulphide ore mechanically accumulated in small sedimentary basins filled by pyroclastics. The total production of the Bor metallogenic zone since 1902 has been near 652 Mt of ore with 4.93 Mt of copper and 280 tons of gold. Mineral resources of the Bor metallogenic zone are estimated at over 20 millions of tons of copper and 1,000 tons of gold. The main geological characteristics of selected metallic mineral deposits in this area are described in this paper.
Bottom-up synthesis of graphene nanoribbons (GNRs) has significantly advanced during the past decade, providing various GNR structures with tunable properties. The synthesis of chiral GNRs, however, ...has been underexplored and only limited to (3,1)-GNRs. We report herein the surface-assisted synthesis of the first heteroatom-doped chiral (4,1)-GNRs from the rationally designed precursor 6,16-dibromo-9,10,19,20-tetraoxa-9a,19a-diboratetrabenzoa,f,j,operylene. The structure of the chiral GNRs has been verified by scanning tunneling microscopy, noncontact atomic force microscopy, and Raman spectroscopy in combination with theoretical modeling. Due to the presence of oxygen–boron–oxygen (OBO) segments on the edges, lateral self-assembly of the GNRs has been observed, realizing well-aligned GNR arrays with different modes of homochiral and heterochiral inter-ribbon assemblies.
Generation of hydroxyl radicals in the Fenton system (FeII/H2O2) is seriously limited by the sluggish kinetics of FeIII reduction and fast FeIII precipitation. Here, boron crystals (C‐Boron) ...remarkably accelerate the FeIII/FeII circulation in Fenton‐like systems (C‐Boron/FeIII/H2O2) to produce a myriad of hydroxyl radicals with excellent efficiencies in oxidative degradation of various pollutants. The surface B−B bonds and interfacial suboxide boron in the surface B12 icosahedra are the active sites to donate electrons to promote fast FeIII reduction to FeII and further enhance hydroxyl radical production via Fenton chemistry. The C‐Boron/FeIII/H2O2 system outperforms the benchmark Fenton (FeII/H2O2) and FeIII‐based sulfate radical systems. The reactivity and stability of crystalline boron is much higher than the popular molecular reducing agents, nanocarbons, and other metal/metal‐free nanomaterials.
The unique B12 unit of crystalline boron experiences step‐wise cleavage of B−B bond and rapidly provides electrons for FeIII reduction to FeII. This boosts the oxidation capability of the Fenton systems remarkably to oxidize a diversity of organic pollutants with exceptional stability.
Trotz des großen präparativen Interesses an Diboranen und der hohen B‐B‐Bindungsenthalpie ist die Knüpfung von Bor‐Bor‐Bindungen immer noch schwierig, kaum zu kontrollieren und schlecht vorhersagbar. ...Methoden zur Herstellung von B‐B‐Mehrfachbindungen sind sogar noch seltener. In den letzten Jahren gab es nun einige Fortschritte zur Lösung dieser Probleme, und dieser Kurzaufsatz unternimmt den Versuch, einen Überblick über die Geschichte der B‐B‐Bindungsbildung zu geben und neue Ergebnisse auf diesem Gebiet zusammenzufassen.
Die Knüpfung von Bor‐Bor‐Bindungen ist trotz der hohen B‐B‐Bindungsenthalpie schwierig, kaum kontrollierbar und unvorhersagbar. Methoden für den Aufbau von B‐B‐Mehrfachbindungen sind sogar noch seltener. In den letzten Jahren gab es einige Fortschritte zur Lösung dieser Probleme, die, zusammen mit dem historischen Hintergrund der B‐B‐Bindungsbildung, hier zusammengefasst werden.
Pure green emitters are essential for realizing an ultrawide color gamut in next‐generation displays. Herein, by fusing the difficult‐to‐access aza‐aromatics onto B (boron)–N (nitrogen) skeleton, a ...hybridized multi‐resonance and charge transfer (HMCT) molecule AZA‐BN was successfully synthesized through an effective one‐shot multiple cyclization method. AZA‐BN shows pure green fluorescence with photoluminance quantum yield of 99.7 %. The corresponding green device exhibits a maximum external quantum efficiency and power efficiency of 28.2 % and 121.7 lm W−1, respectively, with a full width half maximum (FWHM) of merely 30 nm and Commission Internationale de l'Eclairage (CIE) coordinate y of 0.69, representing the purest green bottom‐emitting organic light‐emitting diode.
By fusing aza‐aromatics onto a B−N skeleton, a hybridized multi‐resonance charge‐transfer molecule AZA‐BN was synthesized. The AZA‐BN device exhibits narrow‐band green electroluminescence with a maximum external quantum efficiency/CIE coordinate y of 28.2 %/0.69, representing the purest green bottom‐emitting organic light‐emitting diode.
Prolonged consumption of water contaminated with fluoride ions (F–) at concentrations exceeding 1.5 ppm can lead to considerable health implications, particularly in children and developing embryos. ...With irreversible and potentially severe forms of fluoride (F–) toxicity such as skeletal fluorosis being endemic in at least 25 countries, constructing affordable, remote-access, reliable water-sampling methods for F– contamination is an important goal. In this work, we present a novel lanthanide-based luminescent metal–organic framework, named SION-105, with a boron (B) receptor site whose interactions with F– in aqueous solutions are simultaneously electrostatic and specific in nature because of its carefully designed structural environment. This allows the material to be easily regenerated and used over 10 cycles, setting it apart from most existing molecular and polymeric F– sensors. SION-105 has been combined with a portable prototype sampling device that was designed and built in-house to measure F– concentrations in natural groundwater samples taken from three different countries, with the results showing excellent agreement with ion chromatography analysis.
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•The BN-based nanomaterials present the outstanding removal percentage of organic pollutants.•The BN-based nanomaterials have satisfactory sorption capacities for heavy metal ...ions.•The removal processes of heavy metal ions were mainly attributed to surface complexation.•The interaction mechanism between BN and organic compounds was π-π interaction.
Water pollution, a worldwide issue for the human society, has raised global concerns on environmental sustainability, calling for high-performance materials in effective pollution treatments. Boron nitride (BN) with a structure similar to graphene possesses many extraordinary properties such as high surface areas, high oxidization resistance at high temperature, and high chemical stability. This review presents the outstanding removal percentage and environmental restoration of BN-based nanomaterials for the elimination of various pollutants from the last ten years. Notably, recent advances in the removal of organic/inorganic pollutants and interaction mechanism are outlined. BN-based materials can not only preferably remove contaminants, but also can be directly regenerated by burning in air. The BN-based materials have satisfactory sorption capacities for inorganic pollutants (e.g. heavy metal ions) and organic pollutants (e.g. dyes and pharmaceutical molecules). The interaction mechanisms between pollutants and BN-based materials are mainly surface complexation, π-π stacking, and electrostatic interactions. This paper is beneficial to further comprehend the interactions of pollutants with BN-based materials, which is also helpful for the improvement of BN-based materials and potential areas for future applications in environment remediation.
The search of new borates with improved functional properties has attracted considerable attention. Herein, a new polar fluorooxoborate, NaB4O6F (NBF) was prepared by high‐temperature solid‐state ...reaction. NBF belongs to the AB4O6F family (A=alkali metal or ammonium), a series of compounds that undergoes significant cation‐dependent structural changes. NBF is of particular interest owing to the special cation position. Temperature‐dependent ionic conductivity measurements show that NBF is a solid ionic conductor, and it has the lowest active energy of 32.5 kJ mol−1 of fluorooxoborates. NBF also shows a second‐harmonic generation (SHG) response of 0.9×KH2PO4 and 0.2×β‐BaB2O4, at 1064 and 532 nm, respectively, and it has a short UV cutoff edge below 180 nm. Based on bond valence (BV) concepts, symmetry analysis, and the first principles calculation, the unique B4O6F∞ layer can be regarded as the “multifunctional unit”, which is responsible for the observed properties of NBF.
BOF a nova: A new polar fluorooxoborate, NaB4O6F has been discovered through chemical substitution of the cation. It exhibits better ion conductivity than other alkali‐metal fluorooxoborates and excellent NLO properties.
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