High Molar Research Articles

Impact of the Acceptor Group on the Properties of Triphenylamine-Donor-Acceptor Dyes: An Experimental and Computational Study.

Three triphenylamine-Indane donor-acceptor dyes with different functional groups on the acceptor were studied to investigate how substitution would affect the optical properties. The dyes studied were IndCN, containing two malononitrile groups; InO, with two ketone groups; and InOCN, which features mixed functional groups. A combination of Raman spectroscopy, UV-vis absorption and emission spectroscopy, and density functional theory (DFT) calculations were employed for characterization. The dyes exhibited intramolecular charge transfer transitions with relatively high molar absorptivity (εabs) of ∼50 mM-1 cm-1 at 491-591 nm within the visible spectrum and emissions at 690-840 nm in dichloromethane. The malononitrile-containing dyes showed lower-energy absorption and emissions due to a reduced band gap compared to ketone-containing dyes. The bulkiness of the malononitrile group led to a bent geometry, increasing nonradiative decay and reducing the fluorescence quantum yield. The dyes exhibited fluorescence quantum yields less than 0.25 and lifetimes of ∼5 ns. Resonance Raman spectra and DFT calculations showed that the longer linker group (propen-1-ylidene linker) in these systems reduced the charge-transfer character of the optical transition. The emission intensities of the three dyes were temperature-sensitive, with ketone-containing dyes showing shifts in emission bands as well. This could be due to molecular stacking and intermolecular π-interactions.

Computational and Experimental Study of PVA with F127 and Citric Acid for Electrospinning

Despite the widespread application of electrospun membranes across various scientific fields, there remains a need for a deeper understanding of the molecular interactions between polymers and other compounds in precursor solutions for electrospinning. This study evaluates the molecular conformations of poly(vinyl alcohol) (PVA) with different degrees of hydrolysis (PVA87 and PVA99) and high molar mass, crosslinked with citric acid (CA), using molecular modeling. The solution properties, including rheology and conductivity, were compared to obtain electrospun nanofibers. Additionally, Pluronic-F127® (F127) was incorporated into the PVA/CA system for advanced applications. The molecular modeling results indicate that the degree of hydrolysis affects the intermolecular forces of PVA and the effective binding of CA to the polymer chain. The interactions within the PVA/CA/F127 system vary with the degree of hydrolysis. The high viscosity of PVA99, due to inter- and intramolecular bonds, negatively impacts fiber morphology and formation. Thermal and Raman analyses confirmed crosslinking. Under the conditions used, the PVA99/CA/F127 system is unsuitable for electrospinning. In contrast, the electrospinning and crosslinking of PVA87/CA/F127 with high molar mass yielded better results, enhancing the potential of these nanofibers for drug delivery applications.

Indocarbocyanine-Indodicarbocyanine (sCy3-sCy5) Absorptive Interactions in Conjugates and DNA Duplexes.

Sulfonated indocyanines 3 and 5 (sCy3, sCy5) are widely used to label biomolecules. Their high molar absorption coefficients and lack of spectral overlap with biopolymers make them ideal as linker components for rapid assessment of bioconjugate stoichiometry. We recently found that the determination of the sCy3:sCy5 molar ratio in a conjugate from its optical absorption spectrum is not straightforward, as the sCy3:sCy5 absorbance ratio at the maxima tends to be larger than expected. In this work, we have investigated this phenomenon in detail by studying the spectral properties of a series of sCy3-sCy5 conjugates in which the dyes are separated by linkers of various lengths, including DNA duplexes. It was found that when sCy3 and sCy5 are located in close proximity, they consistently exhibit an "abnormal" absorbance ratio. However, when the two dyes are separated by long rigid DNA-based spacers, the absorbance ratio becomes consistent with their individual molar absorption coefficients. This phenomenon should be taken into account when assessing the molar ratio of the dyes by UV-Vis spectroscopy.

First preclinical SPECT/CT imaging and biodistribution of [165Er]ErCl3 and [165Er]Er-PSMA-617

Background165Er (t1/2 = 10.4 h, Ex-ray = 47.1 keV (59.4%) and 54.3 keV (14.3%)) is a promising radionuclide suitable for targeted Auger electron therapy of cancer. 165Er can be produced at a relatively low cost, high yield, and high purity using small medical cyclotrons. As a late lanthanide, 165Er is easy to label and can be used as a surrogate for other lanthanides or Ac in proof-of-concept studies. In this report, we explore the radiochemistry, in vitro, and in vivo behavior of [165Er]ErCl3 and [165Er]Er-PSMA-617 to showcase the application of this radionuclide. Particularly, we report the first phantom and preclinical SPECT imaging of this radionuclide leveraging its characteristic X-ray photon emissions.ResultsThe 165Ho(p,n)165Er nuclear reaction using a 13 MeV cyclotron demonstrated production yields of up to 25 ± 5 MBq. µA−1 h−1 at the end of the bombardment. After the purification (4.0 ± 0.5 h) using a sequential combination of cation exchange and extraction chromatography, 4-h irradiation produced up to 1.5 GBq of [165Er]ErCl3. High molar activity [165Er]Er-PSMA-617 was prepared (~ 200 MBq/nmol). [165Er]Er-PSMA-617 showed a LogD7.4 value of -2.34 ± 0.24 meaning high hydrophilicity of the complex as expected. The stability of [165Er]Er-PSMA-617 in saline, human, and mouse serum was studied and showed intact tracer after 12 h in all three cases. [165Er]ErCl3 and [165Er]Er-PSMA-617 were both taken up by LNCaP cells. PSMA-617 has IC50 at nanomolar range for [165Er]Er-PSMA-617 in LNCaP cells. SPECT images with preclinical phantoms showed good uniformity, spatial resolution, and quantitative accuracy. SPECT/CT imaging in LNCaP tumor-bearing mice injected with [165Er]Er-PSMA-617 showed high tumor uptake and quantitative accuracy when comparing the results to ex vivo biodistribution %IA/g values. Mice injected with [165Er]ErCl3 showed uptake in bone structures and excretion through both liver and kidneys.ConclusionsThis study demonstrated the preclinical use of 165Er for the first time. Using [165Er]ErCl3 and [165Er]Er-PSMA-617 as examples, the radiochemistry, cell, and animal studies showed that 165Er can be used as a tool for evaluating targeted radiopharmaceuticals. The X-ray emission from 165Er can be used for quantitative SPECT imaging in mice.

Novel benzophenone derivatives for low intensity visible light polymerization and multi-color 3D printing

Four novel benzophenone photoinitiators were synthesized by one-step reaction, including (4-(dimethylamino)phenyl)(10-ethyl-10H-phenothiazin-3-yl)methanone (PEPM), (4-(dimethylamino)phenyl)(10-phenyl-10H-phenothiazin-3-yl)methanone (PPPM), (10-allyl-10H-phenothiazin-3-yl)(4-(dimethylamino)phenyl)methanone (PAPM) and (4-(dimethylamino)phenyl)(10-(hex-5-en-1-yl)-10H-phenothiazin-3-yl)methanone (PHPM). Compared with benzophenone (BP), the absorption spectra of PIs are red-shifted to the visible light range, with a high molar absorption coefficient and wide absorption range from 365 nm to 475 nm. Surprisingly, under the irradiation of low intensity LED@405 nm (5 mW/cm2) and LED@440 nm (5 mW/cm2), PIs can initiate free radical polymerization and undergo rapid polymerization of PEGDA 400. Among them, the double bond conversion rate (DC) of PPPM reaches a stable value (98 %) within 20 s, which is much higher than that of BP (65 %). In addition, the curing depth of PPPM reaches 8.1 cm under the irradiation of LED@440 nm. Besides, PPPM can still perform multi-color 3D printing with 3 s/slice after adding different color (black, red, blue and yellow) dyes. At the same time, we explored the photopolymerization mechanism of the photoinitiator through photodegradation and ESR tests.

Fabrication of Eu2O3 doped in high density and transparent silicoborate scintillating glass for synchrotron X-ray radiographic imaging application

In this work, the glass system, xEu2O3 - 10SrO - 20La2O3 - 10Ta2O5 - 10SiO2 - (50-x)B2O3, where x = 0, 1, 3, 5, 7, 9, 11 mol%, was fabricated using the high-temperature melt quenching method. The physical, optical, and luminescence properties of the glass were investigated to determine its suitability as a scintillation material. The transparent glass sample showed a high density and molar volume up to 4.72 g/cm3 and 40.57 cm3/mol, respectively, reflecting that higher NBOs in glass matrix. This result is also supported by X-rays photoelectron spectroscopy (XPS) spectra. Absorption spectra represented peaks in the ultraviolet to near infrared regions, which can be confirmed the presenting of Eu3+ ion in glass matrix. Under UV excitation, the glass doped with 3 mol% of Eu2O3 shows highest intensity while scintillation light (X-rays induced luminescence) was highest performed at 7 mol%. The integral intensity of radioluminescence of glass is 26 % that of commercial BGO scintillator. The photoluminescence quantum yield (PLQY) was measured and the highest PLQY was correspond with emission intensity. The glass scintillator was used for X-ray imaging at beamline 1.2, Synchrotron Light Research Institute (SLRI), Thailand and the spatial resolution was evaluated. Due to the strong light emission at 615 nm from 5D0 → 7F2 transition of Eu3+, this developed scintillating glass has a potential for X-ray imaging material in radiographic application.

Characterization of Hydrocolloids Extracted from Fenugreek and Sweet Basil Seeds and Their Effect on Rheological Properties of Wheat Starch Paste

Starch-hydrocolloid systems are crucial texturizing agents, ingredients and additives in many food products. The aim of this work was to investigate the effect of extraction temperature on the composition and properties of hydrocolloids extracted from milled fenugreek and sweet basil seeds, as well as the effect of the obtained non-starch polysaccharide preparations on the rheological properties of wheat starch paste. Hydrocolloids were extracted from milled seeds of fenugreek and sweet basil at room temperature (PFRT and PSBRT, respectively) and at 70 °C (PF70 and PSB70, respectively), with the extraction yields ranging from 32 to 47%. Extracted hydrocolloids contained polysaccharides (mainly high molar mass galactomannan) and protein. Preparations extracted at 70 °C from fenugreek (PF70) and sweet basil (PSB70) seeds were characterized by a higher content of polyphenols (16.2% and 50.9%, respectively), as well as higher antioxidant properties compared to preparations extracted at room temperature (PFRT and PSBRT). The 6% share of the fenugreek and sweet basil seed preparations obtained by extraction at room temperature increased the consistency index and reduced the flow behavior index compared to the starch paste without the preparations. The share of fenugreek seed and sweet basil preparations increased (p < 0.05) the tan δ parameter of the starch paste compared to the starch paste without the preparations.

Reversible Addition-Fragmentation Chain-Transfer Polymerization in Supercritical CO2: A Review.

The development of cleaner, more environmentally friendly processes in polymerization technology is crucial due to the prevalent use of volatile organic solvents (VOCs), which are harmful and toxic. Future regulations are likely to limit or ban VOCs. This review explores the use of supercritical solvents, specifically supercritical CO2 (scCO2), in polymerization processes. The study focuses on reversible addition-fragmentation chain-transfer (RAFT) induced homo-polymerization of various monomers using specific chain transfer agents (CTAs) in scCO2. RAFT polymerization, a reversible deactivation radical polymerization (RDRP) polymerization, relies heavily on the choice of CTA, which significantly influences the dispersity and molar mass of the resulting polymers. Stabilizers are also crucial in controlling product specifications for polymerizations in supercritical CO2, except for fluor-based polymers, although they must be removed and preferably recycled to ensure product purity and sustainability. The review notes that achieving high molar mass through RAFT polymerization in scCO2 is challenging due to solubility limits, which lead to polymer precipitation. Despite this, RAFT polymerization in scCO2 shows promise for sustainable, circular production of low molar mass polymers, although these cannot yet be fully considered green products.

Oiling out and solubility measurement, molecular simulation and thermodynamic properties of d-tagatose in four aqueous binary solvent systems at 283.15 to 323.15 K

Solubility of D-Tagatose in four aqueous binary solvent systems from 278.15 K to 323.15 K was determined using the anti-solvent assisted gravimetric method. The solubility increases with temperature in all four binary solvents, with water, a good solvent, exhibiting a similar trend. In addition, the dissolution process generally follows the ’like dissolves like’ rule. The study indicates that the oiling out occurs when water exhibits a high molar fraction in water + 1-propanol, and water + isopropanol. Furthermore, we study the charge of the molecule using the molecular electrostatic potential surface (MEPS), aiming to analyze the molecular interactions. Then, to explain the dissolution behaviors of D-tagatose, the radial distribution function (RDF) by molecular dynamics simulations (MD) revealed a strong correlation between solute–solvent interactions and solubility, with significant solvent–solvent interactions. The solubility data was correlated using the modified Apelblat equation, Van’t Hoff equation, λh equation, and Jouyban-Acree model, with demonstrating the high consistency in the data. Finally, the thermodynamic properties revealed that the dissolution process of D-Tagatose is endothermic, and entropy-driven based on all positive values for ΔsolHo, ΔsolSo, ΔsolGo.

Enhanced Singlet Oxygen Generation in Aggregates of Naphthalene-Fused BODIPY and Its Application in Photodynamic Therapy.

Several reports are available on aggregation-induced emission and its applications in biomedical imaging and other material sciences. However, enhancement of singlet oxygen generation in nanoaggregates is rarely reported. Here, we report the synthesis of Naph-BODIPY Br2, which absorbs at 661 nm (monomer) with a high molar absorption coefficient. The presence of bromine promotes intersystem crossing, thereby enhancing the singlet oxygen quantum yield (ΦΔ ∼ 0.50 in methanol). In order to increase hydrophilicity, we developed Naph-BODIPY Br2 nanoaggregates (∼100 nm), which demonstrated aggregation-induced properties and exhibited a bathochromic shift with an absorption maximum at 757 nm. The bathochromic shift in the UV-vis spectra due to aggregation is corroborated by TD-DFT analysis. The computational data also confirm the presence of a low-lying triplet state, which enhances the generation of singlet oxygen, making it effective for photodynamic therapy. These aggregates showed excellent singlet oxygen generation in aqueous media, compared to their monomeric form and standard methylene blue. Their hydrophilic nature and high singlet oxygen generation enabled significant phototoxicity against human carcinoma cells with IC50 values of 4.06 ± 0.01 and 4.09 ± 0.1 μM, respectively, for MCF-7 and A549 cells upon 5 min exposure to light. Moreover, their phototoxicity further increases with an increasing exposure time of light for both cell lines. Notably, Naph-BODIPY Br2 nanoaggregates exhibited nearly zero dark cell toxicity and effectively induced apoptosis in cancer cells upon light activation, highlighting their potential as powerful photosensitizers for photodynamic cancer therapy.

LC enantioseparation of active pharmaceutical ingredients using rationally synthesized CDRs and chiral molecules with high molar absorptivity.

The synthesis of optically active compounds requires determination of ee, er, and enantiomeric purity. The aim of the present paper is to review the synthesis of several chiral derivatizing reagents (CDRs) in a rational manner, which were successful for the separation and isolation of enantiomers of a variety of active pharmaceutical ingredients and other important and useful racemates. Besides, the application of (i) certain enantiomerically pure amines, either directly or by incorporating each of them as chiral auxiliary in difluorodinitrobenzene or cyanuric chloride moieties to construct the CDR, (ii) (S)-ketoprofen and (S)-levofloxacin as chiral platforms, and (iii) a few isothiocyanates, have been suitably included. Attention is drawn to the use of water micellar mobile phase as the "green" RP-HPLC method and the use of simple achiral derivatization with ninhydrin, particularly. Synthesis of CDRs and their application for enantioseparation of racemates and detagging of certain chromophoric reagent components for obtaining native enantiomers are other interesting features included herein. The methods can be easily used to determine and control enantiomeric purity with advantages over a variety of commercial chiral phases. This comprehensive review not only highlights innovative methodologies for enantioseparation but also underscores their practical applications in controlling and ensuring the enantiomeric purity of pharmaceutical compounds.

Development of a Candidate 11C-Labeled Selective Phosphodiesterase 1 Radioligand for Positron Emission Tomography.

Phosphodiesterases (PDEs) constitute a superfamily of phosphohydrolytic enzymes that regulate intracellular second messenger signaling by hydrolyzing cyclic adenosine monophosphate and cyclic guanosine monophosphate. Among the 11 subfamilies of PDEs, phosphodiesterase 1 (PDE1) stands out due to its broad implications in central and peripheral pathologies. There are three subtypes of PDE1: PDE1A, PDE1B, and PDE1C. While PDE1A and PDE1C are distributed in both the brain and peripheral organs, PDE1B is predominantly expressed in the brain, rendering it an attractive drug target for neurological and psychological disorders. Despite continuous efforts dedicated to the development of novel PDE1 inhibitors, a suitable PDE1 radioligand for human use is currently lacking. In this study, we present the identification and preclinical evaluation of [11C]PF-04822163, a selective radioligand candidate for imaging PDE1 with positron emission tomography. PF-04822163 exhibits excellent potency toward PDE1 and demonstrates great target selectivity over other PDEs. Then, PF-04822163 was labeled with carbon-11 (half-life, 20 min) in favorable radiochemical yields (25 ± 10%, decay-corrected) and high molar activities (106-194 GBq/μmol). Further, in vitro and in vivo evaluations in rodents suggested that [11C]PF-04822163 displayed good brain penetration and a rapid washout. Despite these promising performance characteristics of [11C]PF-04822163, only marginal specific binding was observed in vivo. Further optimization of the scaffold is warranted to obtain favorable pharmacological and ADME properties.

Riboflavin‐Catalyzed Photoinduced Atom Transfer Radical Polymerization

AbstractThe photoATRP of methyl acrylate (MA) is investigated using riboflavin (RF) and CuBr2/Me6TREN as a dual catalyst system under green LED irradiation (λ ≈ 525 nm). Both RF and CuBr2/Me6TREN enhanced oxygen tolerance, enabling effective ATRP in the presence of residual oxygen. High molar mass polymers (up to Mn ≈ 129 000 g·mol−1) with low dispersity (Đ ≤ 1.16) are prepared, and chain‐end fidelity is confirmed through successful chain extension. The molecular masses of the obtained polymer increased linearly with conversion and showed high initiation efficiency. Mechanistic studies by laser flash photolysis reveal that the predominant activator generation mechanism is reductive quenching of RF by Me6TREN (83%, under [CuBr2]/[Me6TREN] = 1/3 condition), supported by polymerization kinetics and thermodynamic calculations.

Synthesis of K+ channel radioligand [18F]5-methyl-3-fluoro-4-aminopyridine and PET imaging in mice

[18F]3-fluoro-4-aminopyridine ([18F]3F4AP) is the first positron emission tomography (PET) radioligand that targets voltage-gated potassium (K+) channels in the brain for imaging demyelination. [18F]3F4AP exhibits high brain penetration, favorable kinetics for PET imaging, and high sensitivity to demyelinating lesions. However, recent studies in awake human subjects indicate lower metabolic stability than in anesthetized animals, resulting in reduced brain uptake. Therefore, there is a need for novel radioligands for K+ channels with suitable pharmacological properties and enhanced metabolic stability. Recent in vitro studies demonstrate that 5-methyl-3-fluoro-4-aminopyridine (5Me3F4AP) exhibits comparable binding affinity to K+ channels, pKa, logD, and membrane permeability as 3F4AP, and a slower enzymatic metabolic rate, suggesting its potential as a K+ channel PET tracer. In this study, we describe the radiochemical synthesis of [18F]5Me3F4AP using an isotope exchange method from the corresponding 3-fluoro-5-methyl-4-nitropyridine N-oxide, followed by a palladium on carbon mediated hydrogenation of the nitro and N-oxide groups. This method yielded [18F]5Me3F4AP with high purity and acceptable molar activity. PET/CT studies using naïve mice demonstrate that [18F]5Me3F4AP effectively crosses the blood–brain barrier and has comparable kinetics to [18F]3F4AP. These findings strongly suggest that [18F]5Me3F4AP is a promising candidate for neuroimaging applications and warrant further studies to investigate its sensitivity to lesions and in vivo metabolic stability.

High-Performance Sodium-Ion Batteries with Graphene: An Overview of Recent Developments and Design.

Due to their low production cost, sodium-ion batteries (SIBs) are considered attractive alternatives to lithium-ion batteries (LIBs) for next generation sustainable and large-scale energy storage systems. However, during the charge/discharge cycle, a large volume strain is resulted due to the presence of a large radius of sodium ions and high molar compared to lithium ions, which further leads to poor cyclic stability and lower reversible capacity. In the past, researchers have devoted significant efforts to explore various anode materials to achieve SIBs with high energy density. Hence, as a promising anode material for SIBs, the two-dimensional (2D) materials including graphene and its derivatives and metal oxides have attracted remarkable attention due to their layered structure and superior physical and chemical properties. The inclusion of graphene and metal oxides with other nanomaterials in electrodes have led to the significant enhancements in electrical conductivity, reaction kinetics, capacity, rate performance and accommodating the large volume change respectively. Moreover, these 2D materials facilitated large surface areas and shorter paths for sodium ion adsorption and transportation respectively. In this review article, the fabrication techniques, structural configuration, sodium ion storage mechanism and its electrochemical performances will be introduced. Subsequently, an insight into the recent advancements in SIBs associated with 2D anode materials (graphene, graphene oxide (GO), transition metal oxides etc.) and other graphene-like elementary analogues (germanene, stanine etc.) as anode materials respectively will be discussed. Finally, the key challenges and future perspectives of SIBs towards enhancing the sodium storage performance of graphene-based electrode materials are discussed. In summary, we believe that this review will shed light on the path towards achieving long-cycling life, low operation cost and safe SIBs with high energy density using 2D anode materials and to be suitably commercialized for large-scale energy storage applications in the future.

Ultra-Pressurized Deposition of Hydrophobic Chitosan Surface Coating on Wood for Fungal Resistance.

Fungi (Neolentinus lepideus, Nl, and Trametes versicolor, Tv) impart wood rot, leading to economic and environmental issues. To overcome this issue, toxic chemicals are commonly employed for wood preservation, impacting the environment and human health. Surface coatings based on antimicrobial chitosan (CS) of high molar mass (145 × 105 Da) were tested as wood preservation agents using an innovative strategy involving ultra-pressurizing CS solutions to deposit organic coatings on wood samples. Before coating deposition, the antifungal activity of CS in diluted acetic acid (AcOOH) solutions was evaluated against the rot fungi models Neolentinus lepideus (Nl) and Trametes versicolor (Tv). CS effectively inhibited fungal growth, particularly in solutions with concentrations equal to or higher than 0.125 mg/mL. Wood samples (Eucalyptus sp. and Pinus sp.) were then coated with CS under ultra-pressurization at 70 bar. The polymeric coating deposition on wood was confirmed through X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM) images, and water contact angle measurements. Infrared spectroscopy (FTIR) spectra of the uncoated and coated samples suggested that CS does not penetrate the bulk of the wood samples due to its high molar mass but penetrates in the surface pores, leading to its impregnation in wood samples. Coated and uncoated wood samples were exposed to fungi (Tv and Nl) for 12 weeks. In vivo testing revealed that Tv and Nl fungi did not grow on wood samples coated with CS, whereas the fungi proliferated on uncoated samples. CS of high molar mass has film-forming properties, leading to a thin hydrophobic film on the wood surface (water contact angle of 118°). This effect is mainly attributed to the high molar mass of CS and the hydrogen bonding interactions established between CS chains and cellulose. This hydrophobic film prevents water interaction, resulting in a stable coating with insignificant leaching of CS after the stability test. The CS coating can offer a sustainable strategy to prevent wood degradation, overcoming the disadvantages of toxic chemicals often used as wood preservative agents.

18F]Trifluoroiodomethane - Enabling Photoredox-mediated Radical [18F]Trifluoromethylation for Positron Emission Tomography.

The development of new tracers for positron emission tomography (PET) is highly dependent on the available synthetic tools for their radiosynthesis. Herein, we present the radiosynthesis and application of [18F]trifluoroiodomethane - the first reagent for broad scope radical [18F]trifluoromethylation chemistry in high molar activity. CF2 18FI can be prepared from [18F]fluoroform with 67±5 % AY and >99 % RCP. Its synthetic utility is demonstrated by the radiosynthesis of previously unprecedented 18F-labeled α-trifluoromethyl ketones and 18F-labeled trifluoromethyl sulfides, important motifs that are present in a range of bioactive compounds. Both protocols are Ru- and photo-mediated and proceed under mild reaction conditions. They show good functional group tolerance evidenced by the respective reaction scopes and make use of easily obtainable starting materials. The products can be isolated in 8.3-11.1 GBq/μmol (starting from ca. 5GBq [18F]fluoride). The applicability to PET tracer synthesis is shown by the radiolabeling of bioactive compounds, such as derivatives of probenecid and febuxostat. In a broader context, this work opens the door to the utilization of radical [18F]trifluoromethylation chemistry for the radiolabeling of PET tracers in high molar activity.

“[18F]Trifluoroiodomethane – Enabling Photoredox‐mediated Radical [18F]Trifluoromethylation for Positron Emission Tomography

The development of new tracers for positron emission tomography (PET) is highly dependent on the available synthetic tools for their radiosynthesis. Herein, we present the radiosynthesis and application of [18F]trifluoroiodomethane – the first reagent for broad scope radical [18F]trifluoromethylation chemistry in high molar activity. CF218FI can be prepared from [18F]fluoroform with 67±5% AY and >99% RCP. Its synthetic utility is demonstrated by the radiosynthesis of previously unprecedented 18F‐labeled a‐trifluoromethyl ketones and trifluoromethyl sulfides, important motifs that are present in a range of bioactive compounds. Both protocols are Ru‐ and photo‐mediated and proceed under mild reaction conditions. They show good functional group tolerance evidenced by the respective reaction scopes and make use of easily obtainable starting materials. The products can be isolated in 8.3‐11.1 GBq/µmol (starting from ca. 5 GBq [18F]fluoride). The applicability to PET tracer synthesis is shown by the radiolabeling of bioactive compounds, such as derivatives of probenecid and febuxostat. In a broader context, this work opens the door to the utilization of radical [18F]trifluoromethylation chemistry for the radiolabeling of PET tracers in high molar activity.

The Influence of Oat β-Glucans of Different Molar Mass on the Properties of Gluten-Free Bread.

The influence of β-glucans on the properties of gluten-free dough and bread is still not fully explained, with the literature suggesting both positive and negative effects. The aim of this study was to investigate the effect of the molar mass of oat β-glucans on the properties of gluten-free bread. Gluten-free breads were baked under standardized conditions from a model gluten-free mix without and with a 1% or 2% share of oat β-glucans of a low molar mass of 24,540 g/mol, a medium molar mass of 85,940 g/mol and a high molar mass of 1,714,770 g/mol. The share of β-glucans affected the increase in water addition to the baking mix and dough yield proportionally to the molar mass and amount of β-glucans. The β-glucans of the highest molar mass, particularly at a 2% share, were most effective in increasing bread volume, reducing hardness and increasing the moisture content of the bread crumb on the day of baking, as well as reducing the increase in hardness and maintaining a high moisture content of the bread crumb after 1 day of storage, compared to bread without added β-glucans.

Development of Two Novel Dibenzosilole-Based Conjugated Polymers with Thieno[3,4-c]pyrrole-4,6-dione for Use in Polymer Solar Cells

The donor-acceptor (D-A) strategy has proven to be one of the most effective methods for tuning the band gaps, absorption characteristics, and optoelectronic properties in conjugated polymers. Two novel D-A conjugated polymers, PDBSTPD-1T and PDBSTPD-2T, were synthesized using dibenzosilole (DBS) and thieno[3,4-c]pyrrole-4,6-dione (TPD) as the building blocks. These polymers were linked through either a single thiophene or two thiophene rings as π-bridges and were copolymerized using a Suzuki coupling reaction. The effect of the incorporation of the different π-bridges on the electrical/optical properties of the prepared copolymers was also investigated. The synthesized polymers, PDBSTPD-1T and PDBSTPD-2T, were soluble in organic solvents and demonstrated high molar mass along with excellent thermal stability. The conjugation of the electron-accepting TPD unit with the electron-donating DBS unit produced relatively deep HOMO levels, which were fine-tuned to be −5.44 and −5.36 eV via the addition of the different π-bridges. PDBSTPD-1T and PDBSTPD-2T displayed absorption wavelengths between 350 and 650 nm with high Eg opt of 2.01 and 1.97 eV, respectively. X-ray diffraction analysis presented several diffraction peaks, and the π-π stacking distances of PDBSTPD-1T and PDBSTPD-2T were 3.45 and 3.65°A, respectively.