Introduction Of Iodine Research Articles

Crown ethers: Small organic molecules unexpectedly hidden in nuclear magnetic resonance

The new class of ten macrocyclic compounds, lactic acid derived crown ethers, was designed and synthesized. They mainly composed of lactic acid and benzene or iodobenzene skeletons, and the introduction of iodine on the benzene ring was crucial to the formation of more regular crown ether conformation, starting from the diacid precursor. They possessed stable and larger cavities than classical macrocycles such as cyclodextrins. These crown ethers were discovered hiding function onto small molecules such as ethyl lactate, methanol, ethanol, aniline and phenol in nuclear magnetic resonance detection.

Tungsten oxide‐iodide/poly‐2‐aminobenzenethiol nanocomposite with iodine intercalation as a promising electrode for potentiometric sensing of Pb2+ ions in water

AbstractTungsten oxide‐iodide/poly‐2‐aminobenzenethiol nanocomposite (WO2I2/P2ABT) is created through the introduction of iodine into polymer chains, where iodine serves as an oxidizing agent during the synthesis process. With a highly porous structure, the sensing capabilities of WO2I2/P2ABT for detecting Pb2+ ions are successfully demonstrated, revealing a Nernstian slope of 26.2 mV/decade. This detection is accomplished through a simple potentiometric technique, employing a simple two‐electrode cell setup. To further validate its performance, cyclic voltammetry is conducted using a three‐electrode system, revealing a remarkable sensitivity of 7.2 × 10−5 A M−1 for Pb2+ ions. The nanocomposite sensor's selectivity is rigorously examined by subjecting it to testing in the presence of 0.01 M interfering ions. The results unequivocally demonstrate that the sensor remains unresponsive to these interfering ions, underscoring its remarkable selectivity for Pb2+ ions. Moreover, the sensor's behavior is evaluated under real‐world conditions using natural samples, where, no indications of interference from other ions are observed. This is estimated by the absence of cyclic peaks in the voltammogram, indicating the sensor's unique ability to selectively detect Pb2+ ions without being perturbed by other ions that may be naturally occurring in the samples. These findings emphasize the nanocomposite sensor's potential for a wide array of applications in environmental monitoring and analytical chemistry. Its extraordinary combination of high sensitivity, impeccable selectivity, and robust performance in practical scenarios establishes it as an invaluable tool for detecting Pb2+ ions across various contexts.

Design, synthesis, and evaluation of n-butylphthalide and ligustrazine hybrids as potent neuroprotective agents for the treatment of ischemic stroke in vitro and in vivo

A series of novel NBP-TMP hybrids with neuroprotective effects were designed and synthesized for the treatment of ischemic stroke. The anti-cerebral ischemic activity of these compounds was screened by evaluating their neuroprotective effects on the oxygen glucose deprivation/reperfusion (OGD/R)-induced SH-SY5Y cell injury model in vitro. Nine compounds 7e, 7h-7i, 7k, 7m-7p and 7r showed better activities on cell viability and LDH levels compared to NBP at the concentration of 6.25 μM. Among them, compound 7m showed the best potency with a percentage of protection 90.2 % compared to NBP (69.2 %) and other compounds. Preliminary structure-activity analysis revealed that the introduction of iodine and N-methylpiperazine groups could significantly improve the neuroprotective effect. Further mechanism research showed that compound 7m could reduce the damage to neuronal mitochondria caused by OGD/R by reducing ROS and increasing mitochondrial membrane potential (MMP), and reduce the apoptosis and necrosis of neurons to play a neuroprotective role. In addition, 7m could regulate the levels of mitochondrial apoptosis pathway-related proteins Bcl-2, Bax, and caspase 3. Finally, in vivo experiments showed that the compound 7m significantly inhibited ischemia-reperfusion injury and cerebral blood flow in rats, and showed a more significant neuroprotective effect than the positive drug NBP at a dose concentration of 20 mg/kg. In conclusion, our results suggest that 7m may be used as a novel lead compound for the future development of anti-cerebral ischemic agents.

Dimension-Controlled Synthesis of Hybrid-Mixed Halide Perovskites for Solar Cell Application.

Despite the rapid improvement of photovoltaic (PV) efficiency in hybrid organic-inorganic metal halide perovskites (HOIPs), the fabrication procedure of a compact thin film in a large-area application is still a tedious work. Apart from the quality of the thin film, the stability of the perovskite materials and the expensive organic hole transport layer (HTL) within the HOIP-based PV device are the major issues that need to be addressed prior to their commercialization. Herein, a unique glass rod-based facile fabrication technique for producing a compact and stable thin film utilizing a mixed-halide-based perovskite precursor solution is demonstrated. The fabricated devices deliver high photoconversion efficiency (PCE) without the use of any HTL and show an excellent stability under ambient conditions. By varying the organic CH3NH3I (MAI) and inorganic PbBr2 content, perovskite materials with different dimensions, i.e., 3D, 2D, and 1D, are synthesized to produce an active layer for PV devices. Although a 2D single-halide perovskite is reported earlier, herein two different mixed-halide 2D perovskites, i.e., MA2PbI2Br2 and MAPb2IBr4, are synthesized successfully, and their performance is compared in detail along with that of 1D and 3D mixed-halide perovskites. The facile synthesized mixed-halide 2D-based MA2PbI2Br2 perovskite shows a PCE of 10.14% with a high stability of 92% after 100 days without encapsulation, which is much superior as compared to that of the mixed-halide 3D MAPbIBr2. The semiconducting behavior as well as the nature of the bandgap of the synthesized compounds is examined by pursuing density functional theory calculations. Specifically, the role of iodine doping to modify the electronic band structure is investigated, and introduction of iodine is found to reduce the effective masses of both electrons and holes in the perovskite material.

Tandem Suzuki Polymerization/Heck Cyclization Reaction to Form Ladder-Type 9,9'-Bifluorenylidene-Based Conjugated Polymer.

The synthesis of ladder-type 9,9'-bifluorenylidene-based conjugated polymer is reported. Unlike the typical synthetic strategy, the new designed ladder-type conjugated polymer is achieved via tandem Suzuki polymerization/Heck cyclization reaction in one-pot. In the preparation process, Suzuki polymerization reaction occurred first and then the intramolecular Heck cyclization followed smoothly under the same catalyst Pd(PPh3)4. The model reaction proved that the introduction of iodine (I) for this tandem reaction can effectively control the sequential bond-forming process and inhibit the additional competitive side reactions. Thus, small-molecule model compounds could be obtained in high yields. The successes of the synthesized small molecule and polymer compounds indicate that the Pd-catalyzed tandem reaction may be an effective strategy for improving extended π-conjugated materials.

Iodine-induced formation of C–pyridinic-N–Co sites on carbon-encapsulated cobalt nanocrystals as electrocatalyst for rechargeable Zn-air batteries

Although transition metal and N co-doped carbon (M-N-C) materials are regarded as the promising electrocatalysts for oxygen reduction reaction (ORR), they still suffer from unsatisfactory activity and stability. Herein, a novel strategy for halogen atom inducing the formation of highly active and stable C–pyridinic-N–Co sites is presented. The iodine doped Co-N-C catalysts formed via a chemical vapor deposition process, which shows a high half-wave potential of 0.85 V and remarkable durability. The introduction of iodine not only lowers the d band center of surface Co atoms and also makes the electronic rearrangement of Co-N-C structure. The unique structure promotes O2 adsorption strength and generate of OOH*, accelerating the ORR process on the surface of catalytically active sites surface. Moreover, as an air electrode in rechargeable Zn-air battery, the catalyst shows a large peak power density of 120 mW cm−2 and high stable cyclability. Even as flexible batteries, the cathode exhibits good stability and flexibility under different bending states.

Iodine doping induced activation of covalent organic framework cathodes for Li-ion batteries.

Covalent organic frameworks (COFs) are considered as promising candidate organic electrode materials for lithium-ion batteries (LIBs) because of their relatively high capacity, ordered nanopores, and limited solubility in electrolyte. However, the practical capacity of COF materials is mainly affected by their low electronic/ionic conductivity and the deep-buried active sites inside the COFs. Here, we synthesize an iodine doped β-ketoenamine-linked COF (2,6-diaminoanthraquinone and 1,3,5-triformylphloroglucinol, denoted as COF-I) by a facile one-pot solvothermal reaction. The introduction of iodine can make the COF more lithiophilic inside and exhibit high intrinsic ion/electron transport, ensuring more accessible active sites of the COFs. Consequently, when used as the cathode of LIBs, COF-I demonstrates a high initial discharge capacity of 140 mA h g-1 at 0.2 A g-1, and excellent cycling stability with 92% capacity retention after 1000 cycles. Furthermore, a reversible capacity of 95 mA h g-1 at 1.0 A g-1 is also achieved after 300 cycles. Our study provides a facile way to develop high-performance COF electrode materials for LIB applications.

Iodine Conjugated Pt(IV) Nanoparticles for Precise Chemotherapy with Iodine-Pt Guided Computed Tomography Imaging and Biotin-Mediated Tumor-Targeting.

Theranostics of platinum (Pt)-based chemotherapy are able to self-track the biodistribution and pharmacokinetics while performing therapeutic effects. Pt-based CT imaging is expected to visualize and monitor the tumor throughout the entire tumor inhibition stage. However, a sufficient Pt concentration is necessary for CT imaging, which may bring about severe nephrotoxicity. A Bio-Pt-I compound is designed and synthesized by conjugation of iodine and biotin to the structure of Pt and further self-assembles into nanoparticles. The introduction of iodine not only enhances the CT imaging signal with a much lower dose of Pt but also overcomes the resistance of tumor cells to Pt-containing nanomedicine by inhibiting the expression of Bcl-2. Furthermore, biotin-mediated tumor targeting increases drug accumulation in tumors. This work combines CT imaging based self-track with efficient cisplatin-resistance reversion ability, which may promote the clinical transformation of Pt-containing nanomedicine.

ВПЛИВ ЗАСТОСУВАННЯ МІКРОЕЛЕМЕНТІВ НА АЗОТНЕ ЖИВЛЕННЯ ПЕТРУШКИ, УРОЖАЙНІСТЬ I ЯКІСТЬ ЗЕЛЕНІ Й КОРЕНЕПЛОДІВ

The article presents the results of vegetation-field studies (for 2018-2020) to study the effect of trace elements on the yield and quality of greens and root crops of parsley on heavy loamy chernozems on loess-like loams. A soil mixture was poured into the vessel at the rate of 10 kg of heavy loamy chernozem. Microelements were introduced into the soil in an amount: boron – 1.0 mg; zinc – 2.5 mg; copper – 0.5 mg; manganese – 5.0 mg; molybdenum – 1.0 mg; cobalt – 1.0 mg; iodine – 2.0 mg of active ingredient per kilogram of soil. In the prepared soil, 100 parsley seeds were sown in vessels at the beginning of May. Trace elements were aplicated in the form of an aqueous solution of salts 20 days before chemical analyzes. Molybdenum in the form of ammonium molybdenum (0.05 % solution), manganese – in the form of manganese sulfate (0.6 %, solution) and boron – in the form of boric acid (0.15 % solution). The experiments were carried out in triplicate. Collecting greens was carried out when the plants reached a height of 20–25 cm, leaving petioles 2 cm high from the head of the root crop. The results of the research found that microelements: boron, copper, manganese, molybdenum and cobalt on chernozem on average over two years contributed to an increase in seed germination by 1.2–1.3 %, and the introduction of iodine into the soil slightly reduced seed germination. Parsley shoots appeared together, which was also influenced by the water–air properties of the soil. At the same time, the plants were well leafy and had a darker green color of the leaves, increased the productivity of greens and parsley root crops. In the variant where organic fertilizers were applied to the soil under the predecessor, the microelements increased the yield. This is due to the fact that organic fertilizers were introduced under the previous crop, when decomposed in the soil, they provide the plants with microelements. The increased yield of parsley root crops was obtained from the introduction of molybdenum and a double dose of copper. An increased yield of root crops compared to the control (without feeding) was obtained, respectively: cobalt – 151 g, double dose of copper – 135 g, copper – 108 g and zinc – 106 g. Thus, the use of trace elements for parsley in order to obtain high yield and quality marketable products are best used on poor soils of these elements.

Electrical and Optical Properties of Nanocomposites Fabricated by the Introduction of Iodine in Porous Dielectric Matrices

The electrical and optical properties of nanocomposite materials fabricated by the dispersion of iodine in porous dielectric matrices of zeolites, zeolite-like aluminum phosphates, opals, asbestos, and porous aluminum oxide are studied. It is demonstrated that the physical properties of the produced nanocomposites depend significantly on the structure of a matrix.

Multi-functional organic field effect transistor based on a dual doped P3HT

<abstract> <p>A dual doped regio-regular poly(3-hexylthiophene-2, 5-diyl) (P3HT) was investigated to develop a multi-functional organic field effect transistor (OFET). OFETs based on a pristine P3HT and a dual doped P3HT (P3HT:PCBM:I<sub>2</sub> blend) were fabricated to study the impact of doping on the electrical properties of the samples, and to examine the mechanism through which it amplified the output performance of the doped OFETs. A series of experimental techniques such as device electrical characterization, active layer surface analysis, and photon absorptivity measurements were conducted to quantitatively characterize the principal parameters that are susceptible to change as a result of doping. Topographic mapping revealed the expected doping-induced improvements in surface morphology, which could be associated with the ability of iodine to improve interdigitation between adjacent P3HT chains. Similarly, absorption spectra showed a 3 nm red-shift of the light absorbance spectrum of the doped samples compared to the undoped samples. The electrical conductivity of the samples was also examined at various conditions of temperature and light intensity, and the values obtained from the doped sample were approximately one order of magnitude higher compared to those of the undoped sample at room temperature, which explains the reason behind the higher output current drawn from the doped device compared to that of the undoped OFET. The explanation for this is two-fold, both PCBM and iodine promote the generation of free charge carriers, which increases the electrical conductivity of the active layer; and in addition to that, the improved P3HT main-chain interdigitation brought about by the introduction of iodine results in an increase in charge-carrier mobility, which also results in higher electrical conductivity. The findings of this study offers valuable information that could be instrumental in further advancing the future organic semiconductors based studies.</p> </abstract>

Highly Selective Hydroiodination of Carbon-Carbon Double or Triple Bonds

Iodine is an element that exhibits characteristic features of heavy halogen, and several compounds containing iodine constitute important synthetic intermediates due to synthetically easy manipulation. To utilize iodine units for organic synthesis, a highly regio- and stereoselective introduction of iodine to versatile building blocks is significant, and a lot of research works for the selective introduction of iodine to alkynes or alkenes have been conducted. In this review article, we describe regio- and stereoselective hydroiodination to multiple bonds of building blocks, and its synthetic applications as key intermediates to construct several important compounds in organic chemistry.

Directing Traffic: Halogen-Bond-Mediated Membrane Transport.

The plasma membrane regulates the transport of molecules into the cell. Small hydrophobic molecules can diffuse directly across the lipid bilayer. However, larger molecules require specific transporters for their entry into the cell. Regulating the cellular entry of small molecules and proteins is a challenging task. The introduction of halogen, particularly iodine, to small molecules and proteins is emerging to be a promising strategy to improve the cellular uptake. Recent studies reveal that a simple substitution of hydrogen atom with iodine not only increases the cellular uptake, but also regulates the membrane transport. The strong halogen-bond-forming ability of iodine atoms plays a crucial role in the transport and the introduction of iodine may provide an efficient strategy for studying membrane activity and cellular functions and improving the delivery of therapeutic agents. This Concept article does not provide a comprehensive picture of membrane transport but highlights halogen-substitution as a novel strategy for understanding and regulating the cell-membrane traffic.

Novel g-C3N4/BiOClxI1-x nanosheets with rich oxygen vacancies for enhanced photocatalytic degradation of organic contaminants under visible and simulated solar light

A novel oxygen vacancy-rich g-C3N4/BiOClxI1-x heterostructure nanosheet (BCI-CN-P) is successfully prepared by a facile coprecipitation method with the assistance of surfactant polyvinylpyrrolidone (PVP) for enhanced photocatalytic degradation of organic contaminants. Field Emission Scanning Electron Microscope and Field Emission Transmission Electron Microscope detect the formation of heterostructure, while X-ray photoelectron spectroscopy and electron spin resonance demonstrate that the surface has rich oxygen vacancies. Under visible light irradiation, BCI-CN-P (g-C3N4/BiOClxI1-x with PVP) exhibits 100% photocatalytic degradation efficiency of colorless bisphenol A (BPA, 10 mg L−1) within 40 min, while CN (pure g-C3N4), BCI (pure BiOClxI1-x), BC-CN-P (g-C3N4/BiOCl with PVP) show negligible decomposition ability, and BCI-CN (g-C3N4/BiOClxI1-x without PVP) displays 61.2% removal efficiency for BPA after 1 h. Similarly, BCI-CN-P shows outstanding photocatalytic performance under simulated solar light, and the apparent reaction rate constant for BPA degradation is 0.2245 min−1, which is around 89.1, 15.2, 5.6 and 18.6 times as that of CN, BCI, BCI-CN and BC-CN-P, respectively. Furthermore, the photocatalytic mechanism of BCI-CN-P is revealed, the introduction of iodine and PVP enhance the visible light absorption ability and the formation of rich oxygen vacancies, and the synergistic effect between the g-C3N4/BiOClxI1-x heterojunction and oxygen vacancies facilitates the effective separation and transfer of photogenerated electron-hole pairs. O2·- radicals and photogenerated holes are confirmed to be main active species to decompose organic pollutants continuously during photocatalytic degradation process. The BCI-CN-P catalyst is excellent and applicable in the broad pH range from 5.0 to 9.0. Also, BCI-CN-P presents outstanding mineralization capability and bio-friendliness for potential practical application.

Crystal and molecular structures of Si-(iodomethyl)silatranes with methyl substituents in β-position relative to the nitrogen atom

Crystal and molecular structures of two silatranes, 1-iodomethyl-3-methyl- and 1-iodomethyl-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-silabicyclo[3.3.3]undecanes, were determined by X-ray analysis. Comparison of their structural and geometrical characteristics with those of other silatranes shows that the presence of methyl substituents β-positioned to nitrogen atoms increases the length of the dative Si←N bond, whereas the introduction of iodine into the axial position of the silatrane slightly decreases the length of the Si←N bond.

Cysteine-based 3-substituted 1,5-benzoxathiepin derivatives: Two new classes of anti-proliferative agents

Two distinct series of the 3-amino-1,5-benzoxathiepin scaffold, derived from L-cysteine, were synthesized and evaluated for their anti-proliferative activity in the breast cancer MDA-MB-231 and MCF-7 cells, and in the ovarian carcinoma SKOV-3 cell line. (3R)-Amino-3,4-dihydro-2H-1,5-benzoxathiepin [(R)-10] was diversified into two forms: (a) by incorporating different amino acids at its position 3, through an amide bond; and (b) by construction of the purine ring to give 6-chloro-9-[2-(3,4-dihydro-2H-1,5-benzoxathiepin-(3R)-yl)]-9H-purine [(R)-28]. Nevertheless, when the introduction of iodine was tried at position 2 of the purine ring of (R)-28, 2-{[2-(6-chloro-2-iodo-9H-purin-9-yl)prop-2-en-1-yl]thio}phenol (34) was obtained. Compound 34 shows activity against cancer cells. Interestingly, 34 inhibits mammosphere formation at the micromolar range, demonstrating activity against cancer stem cells. Although further studies of its targets and mechanism of action are needed, these findings support the therapeutic potential of this compound in cancer.

Improved Flavin-Based Catalytic Photooxidation of Alcohols through Intersystem Crossing Rate Enhancement.

The triplet excited-state formation efficiency in a flavin derivative was increased by the introduction of iodine into the molecular framework. The transient absorption measurements showed that the intersystem crossing rate was 1.1 × 10(10) s(-1), significantly faster than in the parent flavin compound. Furthermore, the photocatalytic efficiency of iodoflavin was evaluated using the oxidation of benzyl alcohol as a model reaction. The benzaldehyde product yields were higher when iodoflavin was used as a photocatalyst, showing that the increased triplet yield directly translates into improved photocatalysis. The iodoflavin catalyst also allowed the use of higher substrate concentrations (since the undesired electron transfer from singlet excited state was minimized), which is expected to improve the practical aspects of photocatalysis by flavins.

Synthesis, spectral luminescent properties, and photostability of monoiodo- and dibromo-substituted BF2-dipyrrinates

4-Iodo-, 4,4′-, and 5,5′-dibromo-substituted BF2-dipyrrinates (BODIPY) have been prepared, and their spectral luminescent properties and photostability have been studied. It has been shown that the introduction of iodine and bromine atoms in the molecule structure results in build-up of the BODIPY phosphorescence and decrease in their fluorescence quantum yield. Basing on the obtained data, the prepared dipyrrinates can be recommended for development of fluorescent sensors for medical and technical applications.

Antiproliferative activities of halogenated pyrrolo[3,2-d]pyrimidines

In vitro evaluation of the halogenated pyrrolo[3,2-d]pyrimidines identified antiproliferative activities in compounds 1 and 2 against four different cancer cell lines. Upon screening of a series of pyrrolo[3,2-d]pyrimidines, the 2,4-Cl compound 1 was found to exhibit antiproliferative activity at low micromolar concentrations. Introduction of iodine at C7 resulted in significant enhancement of potency by reducing the IC50 into sub-micromolar levels, thereby suggesting the importance of a halogen at C7. This finding was further supported by an increased antiproliferative effect for 4 as compared to 3. Cell-cycle and apoptosis studies conducted on the two potent compounds 1 and 2 showed differences in their cytotoxic mechanisms in triple negative breast cancer MDA-MB-231 cells, wherein compound 1 induced cells to accumulate at the G2/M stage with little evidence of apoptotic death. In contrast, compound 2 robustly induced apoptosis with concomitant G2/M cell cycle arrest in this cell model.

ChemInform Abstract: Practical and Efficient ipso‐Iodination of Arylboronic Acids via KF/I2 System.

Abstract A facile and effective iododeboronation of variously substituted aryl and heteroarylboronic acids through activation and subsequent ipso -introduction of iodine is presented. The use of KF and I 2 at 80 °C in 1,4-dioxane furnishes iodinated compounds in high yields.