Hydrogen Borate Research Articles

Synthesis, Biological and Medicinal Evaluation of New Boric Acid Ester Derived From Antibiotic Drug with Some of Its Metal Complexes

Synthesis of new ligand, namely [bis(2-(2-methyl-5-nitro-1H-imidazol-1-yl)ethyl) hydrogen borate] (BIB), utilizing the reaction of metronidazole with boric acid in mole ratio (2:1), as well as the metal complexes with [Ni(II) and Cu(II)], were synthesized. All synthesized compounds were characterized by utilizing spectroscopic techniques such as FTIR, 1H-NMR, thermal analysis (T.G., UV-Vis), and atomic absorption (A.A.S.), as well as micro elemental analysis (C.H.N.), melting point (m.p), magnetic susceptibility, molar conductivity, and chloride content measurements. All complexes were paramagnetic, and the electrolyte and the suggested geometries were tetrahedral for nickel and octahedral for copper. In addition, all the transition metal complexes produced were shown to be antibacterial and antifungal against the bacteria Staphylococcus aureus, Escherichia coli, and the fungus Candida. Also, metronidazole and the ligand were evaluated as anticancer agents against human breast cancer (MCF-7). The results showed that ligand was more active as an anticancer than metronidazole.

New Metronidazole Derivative and Some of its Complexes with Antibiofilm Study

Synthesis of a new ligand, namely [bis(2-(2-methyl-5-nitro-1H-imidazol-1-yl)ethyl) hydrogen borate] (BIB), utilizing the reaction of metronidazole with boric acid in a (2:1) mole ratio The metal complexes were synthesized utilizing the reaction of (NiCl2.6H2O and CuCl2 .2H2O) with (BIB) ligand in a 2:1 (L:M) mole ratio. All synthesized compounds were characterized utilizing spectroscopic techniques such as infrared (FTIR), nuclear magnetic resonance of protons(1H NMR), ultra violet and visible radiation (UV-Vis), thermal analysis (TG), atomic absorption (A.A.S.), micro elemental analysis (C.H.N.S.), melting point (m.p.), magnetic susceptibility, molar conductivity, and chloride content measurements. All complexes were paramagnetic and electrolyte, and the suggested geometries were the tetrahedral of nickel and the distorted octahedral of copper complexes. Against the Gram-negative bacterium Pseudomonas auroginosa (G-), all synthesized compounds were evaluated as anti-biofilm agents. Strikingly, the copper (II) complexes tested exhibit significant activity against biofilms and were better at removing biofilms than metronidazole (an antibiotic that is currently used to treat infections), ligand (BIB), and nickel (II) complexes.

An investigative study on optical and dielectric characteristics of Thiourea Cadmium Hydrogen Borate NLO crystal for photonic applications

Single crystals of Thiourea Cadmium hydrogen borate (TCHB), a hybrid nonlinear optical (NLO) material, are grown from an aqueous solution by slow evaporation solution growth technique at ambient temperature. Characterization studies have been conducted to probe the nonlinear effects of the crystal. The crystalline nature of TCHB is explored using the single crystal X-ray diffraction technique. The chemical composition is resolved by the Fourier transform infrared (FTIR) spectroscopy and energy dispersive X-ray analysis. UV–Vis spectral studies analyze the transparency of the crystal. Optical studies illustrate the UV cut-off wavelength to be 285[Formula: see text]nm with wide window of transparency in the infrared and visible regions. The optical and electrical conductivity studies indicate superior optical response essential for optical computing and photonic applications. The Kurtz powder test has confirmed the NLO capability. The thermal stability is analyzed through a thermogravimetric study. Dielectric and AC conductivity measurements carried out over a wide range of frequencies (100[Formula: see text]Hz to 5[Formula: see text]MHz) for various temperatures establish the semiconducting and photonic capacity of TCBH crystal to be used as photodiodes, optical fibres and laser lights.

Adsorption of Sr(II) cations onto titanium dioxide, doped with Boron atoms

The adsorption of Sr(II) cations by Boron-doped TiO2 was investigated. The adsorbent samples were obtained by liquid-phase sol-gel method using the aqua complex precursor [Ті(ОН2)6]3+‧3Cl- and modifying reagent hydrogen borate Н3ВО3. It was found, that single-phase rutile titanium dioxide or two-phase anatase-rutile oxide materials were formed under the different initial ratios of components. Boron atoms are combined with Oxygen atoms into triangular structural cell ВО3 in the rutile sample 0.5В-ТіО2 and are localized in the surface layer of the nanoparticle material as a grouping =О2ВОН. The introduction of Boron atoms into the structure of the rutile adsorbent causes an increase in its adsorption capacity for the binding of Sr(II) cations in the aqueous electrolyte. The maximal adsorption values for Sr(II) cations by the rutile adsorbent in a neutral electrolyte environment reach 102.3 mg‧g-1, while it is equal to 68.8 mg‧g-1 for the unmodified anatase adsorbent a-TiO2.
 The number of acid adsorption centers ≡ТіОНδ+ on the surface of the rutile adsorbent 0.5В-ТіО2 is ~ 50 units on a surface area of 10 nm2, which is twice the number of centers on the surface of the anatase adsorbent a- ТіО2. Anatase-rutile adsorbents 1.0В-ТіО2 and 1.5В-ТіО2 contain, respectively, 70% and 57% of the anatase phase. They are significantly inferior in adsorption ability toward cations of Sr(II) compared with the rutile adsorbent 0.5В-ТіО2. This is because Boron atoms are mainly localized in the anatase phase and with oxygen atoms form tetrahedral groups of ВО4-.

Third order measurements, thermal and mechanical stress tolerance studies of a nonlinear borate family hybrid crystal towards optoelectronic applications

Highly transparent nonlinear Thiourea cadmium hydrogen borate (TCHB) single crystal grown by slow evaporation method is investigated for optoelectronic applications. Single crystal XRD provides details about the lattice structure. FTIR vibrational spectroscopic study identifies the functionals that make up the crystal system. Elemental composition is determined from the EDAX spectrum. UV spectral analysis is performed to determine the transparency range, absorption edge limit, and band gap value at which the crystal can be run. The linear behavior of TCHB is analysed by studying the optical constants from the transmittance values. TG/DTA analysis is done to find out the thermal stability. Vickers microhardness test classifies TCHB as a soft material and elasticity, brittleness and other mechanical properties are assessed from the hardness value. Second harmonic optical study affirms frequency doubling of Nd:YAG laser. Third order measurements, such as, nonlinear absorption co-efficient (β), nonlinear refraction (n2) and third order susceptibility (χ3) are calculated by the Z scan technique.

Azithromycin “ghost peak”: A solution degradation product of azithromycin via leaching from borosilicate glass volumetric flasks and vials

An interference peak was found while detecting related substances of azithromycin.It is impressive that the degradation peak occurred at about 70 min in the next injection of the test solution (4 mg/mL or higher). Once the degradation peak was observed, it would keep growing. By using a strategy that Q-TOF high resolution mass spectrometry with mechanism-based stress studies, followed by preparative subsequent structure characterization by 1D and 2D NMR, the unknown peak was identified as azithromycin hydrogen borate. It apparently results from azithromycin and residual boron leaching out of the inner surface of the glass volumetric flasks and vials used in the sample preparation.By simulating the above chemical process, boric acid and azithromycin were dissolved in the same extraction diluent and a big interference peak occurred. It was found that boron-free flasks and vials, such as PMP or PP flasks and PTFE or PP vials could be used for the detection of azithromycin related substances to avoid the production of azithromycin hydrogen borate.

A Structurally Robust Chiral Borate Ion: Molecular Design, Synthesis, and Asymmetric Catalysis.

Catalysis by chiral weakly-coordinating anions (WCAs) remains underdeveloped due to the lack of a molecular design strategy for exploiting their characteristics, such as the non-nucleophilic nature. Here, we report the development of a chiral borate ion comprising an O,N,N,O-tetradentate backbone, which ensures hitherto unattainable structural robustness. Upon pairing with a proton, the hydrogen borate acts as an effective catalyst for the asymmetric Prins-type cyclization of vinyl ethers, providing access to structurally and stereochemically defined dihydropyrans. The key to selectivity control is the distinct ability of the borate ion to discriminate the prochiral faces of the acyclic oxonium ion intermediate and dictate the regiochemical outcome. We anticipate that this study paves the way for exploring the untapped potential of WCA catalysis for selective chemical synthesis.

A Structurally Robust Chiral Borate Ion: Molecular Design, Synthesis, and Asymmetric Catalysis

AbstractCatalysis by chiral weakly‐coordinating anions (WCAs) remains underdeveloped due to the lack of a molecular design strategy for exploiting their characteristics, such as the non‐nucleophilic nature. Here, we report the development of a chiral borate ion comprising an O,N,N,O‐tetradentate backbone, which ensures hitherto unattainable structural robustness. Upon pairing with a proton, the hydrogen borate acts as an effective catalyst for the asymmetric Prins‐type cyclization of vinyl ethers, providing access to structurally and stereochemically defined dihydropyrans. The key to selectivity control is the distinct ability of the borate ion to discriminate the prochiral faces of the acyclic oxonium ion intermediate and dictate the regiochemical outcome. We anticipate that this study paves the way for exploring the untapped potential of WCA catalysis for selective chemical synthesis.

Diffusion-Limited Aggregation in Potato Starch and Hydrogen Borate Electrolyte System

Natural growth of diffusion-limited aggregate (DLA), without any external stimuli, in boric acid doped starch system is reported here. Fractals grown were confirmed to be of diffusion-limited aggregate (DLA) pattern having fractal dimension ~1.49. Effect of substrate and humidity on growth pattern has also been discussed. The existence of a different vibration band of H3BO3in FTIR confirmed that growth structures are related to boric acid. XRD pattern has shown broad peak along with some sharp peaks. Broad peak is related to starch’s amorphous nature, as where intense sharp peaks are due to boric acid.

A New Open-framework Iron Borophosphate from Ionic Liquids: KFe[BP2O8(OH)

A new open-framework iron borophosphate, KFe[BP2O8(OH)], has been obtained by ionothermal synthesis from KH2PO4, FeCl3∙4H2O, H3BO3 and [C4mpyr]Br (1-butyl-1-methylpyrrolidinium bromide). Single-crystal X-ray diffraction analysis shows that KFe[BP2O8(OH)] (monoclinic, P21/c, a = 9.372(2) Å , b = 8.146(2)Å , c = 9.587(2) Å, β = 101.18(3)°, V = 718.0(2)Å3 and Z = 4) has a three-dimensional (3-D) framework structure composed by {Fe(III)O5(OH)} octahedra as well as {BO3(OH)} and {PO4} tetrahedra. As anionic structural sub-unit, KFe[BP2O8(OH)], contains an infinite open-branched {[BP2O8(OH)]4-} chain which is formed by alternating {BO3(OH)} and {PO4} tetrahedra. {Fe(III)O5(OH)} octahedra share common O corners with five phosphate tetrahedra and the OH corner links to the hydrogen borate group to give a 3D framework. The negative charges of the inorganic framework are balanced by K+ ions.