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Molecules (Basel, Switzerland) Oct 2020The recently proved one-to-one structural equivalence between a conjugated hydrocarbon CH and the corresponding borane BH is applied here to hybrid systems, where each...
The recently proved one-to-one structural equivalence between a conjugated hydrocarbon CH and the corresponding borane BH is applied here to hybrid systems, where each C=C double bond in the hydrocarbon is consecutively substituted by planar B(H)B moieties from diborane(6). Quantum chemical computations with the B3LYP/-pVTZ method show that the structural equivalences are maintained along the substitutions, even for non-planar systems. We use as benchmark aromatic and antiaromatic (poly)cyclic conjugated hydrocarbons: cyclobutadiene, benzene, cyclooctatetraene, pentalene, benzocyclobutadiene, naphthalene and azulene. The transformation of these conjugated hydrocarbons to the corresponding boranes is analyzed from the viewpoint of geometry and electronic structure.
Topics: Boranes; Boron; Carbon; Models, Chemical
PubMed: 33138268
DOI: 10.3390/molecules25215026 -
Molecules (Basel, Switzerland) May 2020In recent years borate-based crystals has attracted substantial interest among the research community. The overall importance of this family of materials is reflected in... (Review)
Review
In recent years borate-based crystals has attracted substantial interest among the research community. The overall importance of this family of materials is reflected in miscellaneous articles and several reviews that have been published over the years. Crystalline borate materials exhibit numerous interesting physical properties, which make them promising for further practical applications. Diversity of functional characteristics results from their high structural flexibility caused in the linkage of planar/non-planar BO groups and BO tetrahedra, which can occur as isolated or condensed structural units. This report is a brief review on crystal chemistry and structure features of anhydrous/high-temperature borates. Polymorphism of boron-oxygen radicals has been considered basing on cations' nature and synthesis conditions. Analysis of the laws governing borates structures and general principles of their systematics was discussed. As a result, an alternative classification of anhydrous compounds has been considered. It is based on four orders of their subdivision: (1) by the variety of anion formers, (2) by the cation charge, (3) by the N = N:N, i.e., ratio of metal atoms number to the ratio of boron atoms number (N-factor) value indicating the borate structural type (if it is known), (4) by the cation type and size.
Topics: Anions; Borates; Boron; Cations; Crystallography, X-Ray; Free Radicals; Hot Temperature; Models, Chemical; Oxygen; Static Electricity; Terminology as Topic
PubMed: 32466152
DOI: 10.3390/molecules25102450 -
Molecules (Basel, Switzerland) Apr 2022Herein, we report the synthesis of sulfur-substituted boron(III) subphthalocyanines (SubPcs) with cationic axial ligands. Subphthalocyanines were synthesized by a...
Herein, we report the synthesis of sulfur-substituted boron(III) subphthalocyanines (SubPcs) with cationic axial ligands. Subphthalocyanines were synthesized by a condensation reaction using the corresponding phthalonitriles and boron trichloride as a template. An aminoalkyl group was introduced on the central boron atom; this process was followed by -methylation to introduce a cationic axial ligand. The peripheral sulfur groups shifted the Q band of SubPcs to a longer wavelength. The cationic axial ligands increased the polarity and enhanced the hydrophilicity of SubPcs. The effect of axial ligands on absorption and fluorescence properties is generally small. However, a further red shift was observed by introducing cationic axial ligands into the sulfur-substituted SubPcs. This change is similar to that in sulfur-substituted silicon(IV) phthalocyanines. The unique effect of the cationic axial ligand was extensively investigated by theoretical calculations and electrochemistry. In particular, the precise oxidation potential was determined using ionization potential measurements. Thus, the results of the present study provide a novel strategy for developing functional dyes and pigments based on SubPcs.
Topics: Boron; Cations; Indoles; Ligands; Sulfur
PubMed: 35566117
DOI: 10.3390/molecules27092766 -
Nature Protocols Mar 2017Boronic acids and esters have critical roles in the areas of synthetic organic chemistry, molecular sensors, materials science, drug discovery, and catalysis. Many of...
Boronic acids and esters have critical roles in the areas of synthetic organic chemistry, molecular sensors, materials science, drug discovery, and catalysis. Many of the current applications of boronic acids and esters require materials with very low levels of transition metal contamination. Most of the current methods for the synthesis of boronic acids, however, require transition metal catalysts and ligands that must be removed via additional purification procedures. This protocol describes a simple, metal- and additive-free method of conversion of haloarenes directly to boronic acids and esters. This photoinduced borylation protocol does not require expensive and toxic metal catalysts or ligands, and it produces innocuous and easy-to-remove by-products. Furthermore, the reaction can be carried out on multigram scales in common-grade solvents without the need for reaction mixtures to be deoxygenated. The setup and purification steps are typically accomplished within 1-3 h. The reactions can be run overnight, and the protocol can be completed within 13-16 h. Two representative procedures that are described in this protocol provide details for preparation of a boronic acid (3-cyanopheylboronic acid) and a boronic ester (1,4-benzenediboronic acid bis(pinacol)ester). We also discuss additional details of the method that will be helpful in the application of the protocol to other haloarene substrates.
Topics: Benzene; Boron; Halogens; Photochemical Processes; Temperature
PubMed: 28230850
DOI: 10.1038/nprot.2016.184 -
International Journal of Molecular... Jun 2018Boron (B) is an essential trace element required for the physiological functioning of higher plants. B deficiency is considered as a nutritional disorder that adversely... (Review)
Review
Boron (B) is an essential trace element required for the physiological functioning of higher plants. B deficiency is considered as a nutritional disorder that adversely affects the metabolism and growth of plants. B is involved in the structural and functional integrity of the cell wall and membranes, ion fluxes (H⁺, K⁺, PO₄, Rb⁺, Ca) across the membranes, cell division and elongation, nitrogen and carbohydrate metabolism, sugar transport, cytoskeletal proteins, and plasmalemma-bound enzymes, nucleic acid, indoleacetic acid, polyamines, ascorbic acid, and phenol metabolism and transport. This review critically examines the functions of B in plants, deficiency symptoms, and the mechanism of B uptake and transport under limited B conditions. B deficiency can be mitigated by inorganic fertilizer supplementation, but the deleterious impact of frequent fertilizer application disrupts soil fertility and creates environmental pollution. Considering this, we have summarized the available information regarding alternative approaches, such as root structural modification, grafting, application of biostimulators (mycorrhizal fungi (MF) and rhizobacteria), and nanotechnology, that can be effectively utilized for B acquisition, leading to resource conservation. Additionally, we have discussed several new aspects, such as the combination of grafting or MF with nanotechnology, combined inoculation of arbuscular MF and rhizobacteria, melatonin application, and the use of natural and synthetic chelators, that possibly play a role in B uptake and translocation under B stress conditions.
Topics: Agriculture; Biological Transport; Boron; Crops, Agricultural; Fertilizers; Humans; Melatonin; Mycorrhizae; Nanoparticles; Nanotechnology; Rhizobiaceae
PubMed: 29937514
DOI: 10.3390/ijms19071856 -
Chemical & Pharmaceutical Bulletin Jul 2020A novel polymer (PEG-carborane), self-assembling into spherical vesicles (boron-containing vesicles, BCVs), could be quickly taken up by tumor cells and had an enhance...
A novel polymer (PEG-carborane), self-assembling into spherical vesicles (boron-containing vesicles, BCVs), could be quickly taken up by tumor cells and had an enhance stability in the bloodstream in previous study. To have more comprehensive understanding of BCVs, endocytic mechanism and cytotoxicity assessment were conducted. The results showed that BCVs were taken up in the intact form with cholesterol-dependent pathway during endocytosis, and BCVs exhibited nearly no cytotoxicity. BCVs could accumulate within tumors for at least 24 h. The data would provide reference information and guidance for BCVs' multifunctional application serving as a boron delivery agent for boron neutron capture therapy (BNCT), a hydrophilic and/or hydrophobic drug carrier and a diagnostic imaging fluorescent probe.
Topics: Animals; Apoptosis; Boron; Boron Neutron Capture Therapy; Cell Cycle; Cell Line; Drug Carriers; Endocytosis; Fluorescent Dyes; Glioma; Humans; Hydrophobic and Hydrophilic Interactions; Mice; Neoplasms, Experimental; Optical Imaging; Particle Size; Surface Properties
PubMed: 32404579
DOI: 10.1248/cpb.c19-00971 -
Plant Physiology Dec 2021Transport of metalloids including B, Si, and As is mediated by a combination of channels and efflux transporters in plants, which are strictly regulated in response to... (Review)
Review
Transport of metalloids including B, Si, and As is mediated by a combination of channels and efflux transporters in plants, which are strictly regulated in response to environmental changes.
Topics: Arsenic; Biological Transport; Boron; Membrane Transport Proteins; Metalloids; Plant Physiological Phenomena; Silicon
PubMed: 35235670
DOI: 10.1093/plphys/kiab326 -
Biochemical Society Transactions Aug 2020Membrane transporters control the movement and distribution of solutes, including the disposal or compartmentation of toxic substances that accumulate in plants under... (Review)
Review
Membrane transporters control the movement and distribution of solutes, including the disposal or compartmentation of toxic substances that accumulate in plants under adverse environmental conditions. In this minireview, in the light of the approaching 100th anniversary of unveiling the significance of boron to plants (K. Warington, 1923; Ann. Bot.37, 629) we discuss the current state of the knowledge on boron transport systems that plants utilise to combat boron toxicity. These transport proteins include: (i) nodulin-26-like intrinsic protein-types of aquaporins, and (ii) anionic efflux (borate) solute carriers. We describe the recent progress made on the structure-function relationships of these transport proteins and point out that this progress is integral to quantitative considerations of the transporter's roles in tissue boron homeostasis. Newly acquired knowledge at the molecular level has informed on the transport mechanics and conformational states of boron transport systems that can explain their impact on cell biology and whole plant physiology. We expect that this information will form the basis for engineering transporters with optimised features to alleviate boron toxicity tolerance in plants exposed to suboptimal soil conditions for sustained food production.
Topics: Boron; Membrane Transport Proteins; Plant Proteins; Plants; Protein Conformation; Soil
PubMed: 32779723
DOI: 10.1042/BST20200164 -
The Journal of Organic Chemistry Feb 2024Over the last century, nucleoside-based therapeutics have demonstrated remarkable effectiveness in the treatment of a wide variety of diseases from cancer to HIV. In...
Over the last century, nucleoside-based therapeutics have demonstrated remarkable effectiveness in the treatment of a wide variety of diseases from cancer to HIV. In addition, boron-containing drugs have recently emerged as an exciting and fruitful avenue for medicinal therapies. However, borononucleosides have largely been unexplored in the context of medicinal applications. Herein, we report the synthesis, isolation, and characterization of two novel boron-containing nucleoside compound libraries which may find utility as therapeutic agents. Our synthetic strategy employs efficient one-step substitution reactions between a diverse variety of nucleoside scaffolds and an assortment of -alkyl potassium trifluoroborate-containing electrophiles. We demonstrated that these alkylation reactions are compatible with cyclic and acyclic nucleoside substrates, as well as increasing alkyl chain lengths. Furthermore, regioselective control of product formation can be readily achieved through manipulation of base identity and reaction temperature conditions.
Topics: Nucleosides; Boron; Boron Compounds; Alkylation
PubMed: 38227951
DOI: 10.1021/acs.joc.3c02179 -
Molecules (Basel, Switzerland) Dec 2020This review is mainly focused on the optoelectronic properties of diamond-based one-dimensional-metal-oxide heterojunction. First, we briefly introduce the research... (Review)
Review
This review is mainly focused on the optoelectronic properties of diamond-based one-dimensional-metal-oxide heterojunction. First, we briefly introduce the research progress on one-dimensional (1D)-metal-oxide heterojunctions and the features of the p-type boron-doped diamond (BDD) film; then, we discuss the use of three oxide types (ZnO, TiO and WO) in diamond-based-1D-metal-oxide heterojunctions, including fabrication, epitaxial growth, photocatalytic properties, electrical transport behavior and negative differential resistance behavior, especially at higher temperatures. Finally, we discuss the challenges and future trends in this research area. The discussed results of about 10 years' research on high-performance diamond-based heterojunctions will contribute to the further development of photoelectric nano-devices for high-temperature and high-power applications.
Topics: Boron; Diamond; Metals; Microscopy, Electron, Scanning; Organic Chemicals; Oxides
PubMed: 33375703
DOI: 10.3390/molecules26010071