Dissociation Energy Research Articles

Low-Migration Compounds with Amine Functionality as Coinitiators of Radical Polymerization.

The utilization of two-component systems comprising camphorquinone (CQ) and aromatic amines has become prevalent in the photopolymerization. However, there are still concerns about the safety of this CQ/amine system, mainly because of the toxicity associated with the leaching of aromatic amines. In light of these concerns, this study aims to develop novel coinitiator combinations featuring CQ and amines which cannot be leached out of materials, enabling free radical polymerization of representative dentalmethacrylate resins under blue light irradiation. This approach involves the initial design and analysis of hydrogen donors with low C─H bond dissociation energy through molecular modeling. Subsequently, copolymerizable methacrylate functional groups are incorporated via chemical modification, allowing it to act as both coinitiator and copolymerization monomer to achieve low migrationand leachability properties. This work presents, for the first time, the synthesis of the innovative coinitiator and compares its performance with the benchmark CQ/ethyl-4-dimethylaminobenzoate (EDB)-based photoinitiation system (PIS). The results demonstrate the effectiveness of the newly proposed PIS. Finally, an in-depth investigation is conducted into the reaction mechanism associated with this PIS through molecular orbital calculations and electron spin resonance studies.

Tert‐Butyl as a Functional Group: Non‐Directed Catalytic Hydroxylation of Sterically Congested Primary C−H Bonds

AbstractThe tert‐butyl group is a common aliphatic motif extensively employed to implement steric congestion and conformational rigidity in organic and organometallic molecules. Because of the combination of a high bond dissociation energy (~100 kcal mol−1) and limited accessibility, in the absence of directing groups, neither radical nor organometallic approaches are effective for the chemical modification of tert‐butyl C−H bonds. Herein we overcome these limits by employing a highly electrophilic manganese catalyst, [Mn(CF3bpeb)(OTf)2], that operates in the strong hydrogen bond donor solvent nonafluoro‐tert‐butyl alcohol (NFTBA) and catalytically activates hydrogen peroxide to generate a powerful manganese‐oxo species that effectively oxidizes tert‐butyl C−H bonds. Leveraging on the interplay of steric, electronic, medium and torsional effects, site‐selective and product chemoselective hydroxylation of the tert‐butyl group is accomplished with broad reaction scope, delivering primary alcohols as largely dominant products in preparative yields. Late‐stage hydroxylation at tert‐butyl sites is demonstrated on 6 densely functionalized molecules of pharmaceutical interest. This work uncovers a novel disconnection approach, harnessing tert‐butyl as a potential functional group in strategic synthetic planning for complex molecular architectures.

Tert-Butyl as a Functional Group: Non-Directed Catalytic Hydroxylation of Sterically Congested Primary C-H Bonds.

The tert-butyl group is a common aliphatic motif extensively employed to implement steric congestion and conformational rigidity in organic and organometallic molecules. Because of the combination of a high bond dissociation energy (~ 100 kcal mol-1) and limited accessibility, in the absence of directing groups, neither radical nor organometallic approaches are effective for the chemical modification of tert-butyl C-H bonds. Herein we overcome these limits by employing a highly electrophilic manganese catalyst, [Mn(CF3bpeb)(OTf)2], that operates in the strong hydrogen bond donor solvent nonafluoro-tert-butyl alcohol (NFTBA) and catalytically activates hydrogen peroxide to generate a powerful manganese-oxo species that effectively oxidizes tert-butyl C-H bonds. Leveraging on the interplay of steric, electronic, medium and torsional effects, site-selective and product chemoselective hydroxylation of the tert-butyl group is accomplished with broad reaction scope, delivering primary alcohols as largely dominant products in preparative yields. Late-stage hydroxylation at tert-butyl sites is demonstrated on 6 densely functionalized molecules of pharmaceutical interest. This work uncovers a novel disconnection approach, harnessing tert-butyl as a potential functional group in strategic synthetic planning for complex molecular architectures.

Unveiling the influence of hydrophobicity on inhibiting hydrogen dissociation for enhanced photocatalytic hydrogen evolution of covalent organic frameworks

Covalent organic frameworks (COFs) have gained considerable interest as candidate photocatalysts for hydrogen evolution. In this work, we synthesized β-keto-enamine-based COFs (TpPa-X, TpDB, and TpDTP) to explore the relations between structures and photocatalytic hydrogen evolution. COFs were divided into two groups: (1) TpPa-X with different substituents attached to the TpPa backbone and (2) COFs featuring diamine linkers of varied lengths (TpDB and TpDTP). Experiments and density functional theory (DFT) calculations show that moderate hydrophobicity is favorable for the photocatalytic hydrogen evolution process, and acceptable contact angles are anticipated to range from 65° to 80°. Naturally, there are comprehensive factors that affect photocatalytic reactions, and the regulation of different backbones and substituents can considerably affect the performance of COFs for photocatalytic hydrogen evolution in terms of electronic structure, specific surface area, surface wettability, carrier separation efficiency, and hydrogen dissociation energy. Results show that TpPa-Cl2 (TpPa-X, X = Cl2) demonstrates the highest photocatalytic activity, approximately 14.51 mmol g-1h−1, with an apparent quantum efficiency of 4.62 % at 420 nm. This work provides guidance for designing efficient COF-based photocatalysts.

Modeling and analysis of synergistic phenolic antioxidants in edible oil: Integrating molecular simulation and artificial neural network approach

Oxidation causes edible oil deterioration affecting nutrition and safety. Antioxidants delay aging, but selecting compounds experimentally is time-consuming and arbitrary. Thus, a rapid and rational screening method for synergistic antioxidants is essential. This study evaluates the antioxidant effects and mechanisms of four phenolic antioxidants on the oil matrix using multiscale simulation. Tert-butylhydroquinone (TBHQ) exhibited the lowest dissociation energy (226.92 kJ/mol), followed by flavanol (TP) (233.00 kJ/mol). Syringic acid (CA) showed the smallest mean square displacement value. An artificial neural network (ANN) was established to analyze the synergistic and antagonistic interactions between TBHQ and TP, predicting optimal synergy at 3.6 mg TP and 1.8 mg TBHQ. The relative prediction deviation (RPD) value of the validation set was 3.91, and the relative error production (RER) value was 1.87 %. Fourier transform infrared spectroscopy experiments validated this synergy. This research establishes a screening system for compound antioxidants and models the synergistic effects of phenolic antioxidants in edible oil, offering theoretical and technical support for their application in the food industry.

Molybdenum diselenide/polymeric carbon nitride dual-homojunction photocatalyst with multi-step charge transfer for efficient catalytic carbon dioxide reduction

Due to the high dissociation energy of carbon dioxide (CO2) and sluggish charge transfer dynamics, photocatalytic CO2 reduction with high performance remains a huge challenge. Herein, we report a novel dual-homojunction photocatalyst comprising of cyano/cyanamide groups co-modified carbon nitride (CN-TH) intramolecular homojunction and 1 T/2H-MoSe2 homojunction (denoted as 1 T/2H-MoSe2/CN-TH) for enhanced photocatalytic CO2 reduction. In this dual-homojunction photocatalyst, the intramolecular CN-TH homojunction could promote the intralayer charge separation and transfer owing to the strong electron-withdrawing capabilities of the two-type cyanamide, while the 1 T/2H-MoSe2 homojunction mainly contributes to a promote interlayer charge transport of CN-TH. This could consequently induce a tandem multi-step charge transfer and accelerate the charge transfer dynamics, resulting in enhanced CO2 reduction activities. Thanks to this tandem multi-step charge transfer, the optimized 1 T/2H-MoSe2/CN-TH dual-homojunction photocatalyst presented a high CO yield of 27.36 μmol·g−1·h−1, which is 3.58 and 2.87 times higher than those of 1 T/2H-MoSe2/CN and 2H-MoSe2/CN-TH single homojunctions, respectively. This work provides a novel strategy for efficient CO2 reduction via achieving a tandem multi-step charge transfer through designing dual-homojunction photocatalyst.

Relative reactivity of methyl anisole isomers: An experimental and kinetic modelling study

Due to the current interest in biomass derived carbon neutral fuels and fuel additives for gasoline engines and to the growing need of understanding the fundamentals of gas phase combustion in the context of wildfires, this study investigates the combustion behavior of key components of biomass pyrolysis oils, namely the three methylanisole isomers (ortho-, meta- and para-methylanisole). Specifically, this study presents the first experimental ignition delay time measurements for such fuels using a shock tube and a rapid compression machine. Ignition experiments were carried out for stoichiometric fuel/air mixtures (φ = 1) at compressed pressure pc = 10 and 20 bar, covering a temperature range Tc = 880–1220 K. A kinetic model based on previous efforts in the area of oxygenated aromatic hydrocarbon fuels is proposed to reproduce and interpret the experimental findings, specifically focusing on capturing the observed different reactivity of the three isomers. To this aim, thermodynamic properties of primary intermediates and bond dissociation energies were calculated highlighting relevant differences originated from the relative position of the O–CH3 and –CH3 substituents. In addition, an isomerization pathway specific to the ortho isomer was theoretically investigated and found to motivate the observed higher reactivity with respect to the meta and para isomers

Strategies for Tuning Tensile Strain and Localized Electrons in a Mo‐Doped NiCoCu Alloy for Enhancing Ampere‐Level Current Density HER Performance

AbstractDeveloping high‐activity non‐noble metal catalysts for improving the ability of water dissociation and H* adsorption/desorption in the hydrogen evolution reaction (HER) process in alkaline and neutral electrolytes is essential but remains challenging. Herein, a Mo‐doped NiCoCu alloy with tuned tensile strain and localized electrons is designed and synthesized by combining the solvothermal and annealing methods for achieving ampere‐level HER performance. Theoretical calculation results prove that Mo doping induces lattice tensile strain and localized electrons (electrons from Mo to the Ni/Co/Cu atoms), promoting the adsorption of O* and H* from H2O molecules on the Mo and Co sites and accelerating water dissociation. Therefore, NiCoCu‐Mo0.078/CF (CF = copper foam) shows low water dissociation energy, providing sufficient H* during the HER process. Meanwhile, its H* Gibbs free energy value is near zero, implying a rapid H* adsorption/desorption process. Electrochemical results show that NiCoCu‐Mo0.078/CF achieves better HER intrinsic activity in both a 1.0 m KOH (η−10 /η−1000 = 35/212 mV) and a 1.0 m phosphate buffer solution (η−10 /η−1000 = 24/256 mV) compared to NiCoCu‐Mo0/CF and NiCoCu‐Mo0.163/CF, and it can continuously operate for 100 h at −1000 mA cm−2. This work shows a sustainable way to design high‐performance catalysts for water electrolysis and proposes a well‐performing HER catalyst.

High-Rate and Selective C2H6-to-C2H4 Photodehydrogenation Enabled by Partially Oxidized Pdδ+ Species Anchored on ZnO Nanosheets under Mild Conditions.

Photocatalytic C2H6-to-C2H4 conversion is very promising, yet it remains a long-lasting challenge due to the high C-H bond dissociation energy of 420 kJ mol-1. Herein, partially oxidized Pdδ+ species anchored on ZnO nanosheets are designed to weaken the C-H bond by the electron interaction between Pdδ+ species and H atoms, with efforts to achieve high-rate and selective C2H6-to-C2H4 conversion. X-ray photoelectron spectra, Bader charge calculations, and electronic localization function demonstrate the presence of partially oxidized Pdδ+ sites, while quasi-in situ X-ray photoelectron spectra disclose the Pdδ+ sites initially adopt and then donate the photoexcited electrons for C2H6 dehydrogenation. In situ electron paramagnetic resonance spectra, in situ Fourier transform infrared spectra, and trapping agent experiments verify C2H6 initially converts to CH3CH2OH via ·OH radicals, then dehydroxylates to CH3CH2· and finally to C2H4, accompanied by H2 production. Density-functional theory calculations elucidate that loading Pd site can lengthen the C-H bond of C2H6 from 1.10 to 1.12 Å, which favors the C-H bond breakage, affirmed by a lowered energy barrier of 0.04 eV. As a result, the optimized 5.87% Pd-ZnO nanosheets achieve a high C2H4 yield of 16.32 mmol g-1 with a 94.83% selectivity as well as a H2 yield of 14.49 mmol g-1 from C2H6 dehydrogenation in 4 h, outperforming all the previously reported photocatalysts under similar conditions.

The impact of incorrect dissociation energies on inferred photospheric abundances

ABSTRACT Spectral synthesis codes are essential for inferring stellar parameters and detailed chemical abundances. These codes require many physical inputs to predict an emergent spectrum. Developers adopt the best measurements of those inputs at the time they release their code, but those measurements usually improve over time faster than the software is updated. In general, the impact of using incorrect or uncertain dissociation energies is largely unknown. Here, we evaluate how incorrect dissociation energies impact abundances measured from C2, CN, CH, TiO, and MgO features. For each molecule, we synthesized optical spectra of FGKM-type main-sequence and giant stars using the literature dissociation energy and an incorrect (perturbed) dissociation energy. We find that the uncertainties in the dissociation energies adopted by spectral synthesis codes for CN, CH, TiO, and MgO lead to negligible differences in flux or abundance. C2 is the only diatomic molecule where the uncertainty of the inputted dissociation energy translates to a significant difference in flux and carbon abundance differences of up to 0.2 dex. For solar-like stars, the impact on carbon abundance is up to 0.09 dex. These large abundance differences demonstrate the importance of updating the inputs adopted by spectral synthesis codes, as well as a consensus on appropriate values between different codes.

Derivation of Morse potential

The Morse potential is widely used in chemistry, physics, and material science to describe interatomic interactions. We show that the Morse potential can be derived from a simple screened charge model accounting for the shielding of the nuclear charge by electron density. In this model, the parameter governing the width of the potential is related to the average shielding strength and the exponents of the atomic orbitals used in electronic structure calculations. The parameter representing the bond dissociation energy of a diatomic molecule is derived by combining the quantum mechanical covalent and classical electrostatic interactions. Moreover, the revealed connection between the parameters of the Morse potential and Pauling’s bond order and electronegativity provides insight into the relation between the classical and quantum mechanical descriptions of chemical bonds. This derivation of the Morse potential from the atomic quantities is expected to contribute to the development of the new basis sets incorporating Slater-type orbitals for electronic structure calculations and the transferable reactive force fields for molecular dynamics simulations. Furthermore, this interpretation of the Morse potential helps to understand the relationships between widely used chemical concepts, including effective atomic charge, bond dissociation energy, electronegativity, and bond order.

Exploring factors affecting the dissociation energies of C–O and C–C bonds in lignin oligomers

The bond dissociation energy (BDE) of lignin is a key factor for lignin depolymerization, assisting in revealing the depolymerization mechanism. However, the impact of substituent as well as solvent, which usually stay together, on BDE of lignin remains unclear. Here, density functional theory (DFT) calculation is employed to compute the BDE of C–O and C–C bonds in lignin oligomers with six substituents in four solvents. The relationship models between multiple factors and BDE are established using random forest algorithm, achieving a predictive accuracy of 0.97. The results show that oxidating hydroxyl to ketone benefits the cleavage of β-O-4 and β-1 bonds. Hydroxyl and methoxy effectively contribute to breaking the Cβ-1 and Cα–Cβ bonds in the β-1 dimer. Polar solvents combined with hydroxyl promote C–O bond dissociation, while alkyl-containing solvents favor C–C bond dissociation. These findings provide valuable insights into lignin depolymerization, pre-depolymerization structural modifications, and the prediction of depolymerization pathways.

Nonlinear optical properties of KnCl (n = 2–7) superalkali clusters

The lowest energy structures along with the low lying isomer, stabilities, electronic properties, optical properties and nonlinear optical responses of KnCl (n = 2–7) clusters were studied within the density functional theory. The second order energy difference, dissociation energy and GH-L (HOMO–LUMO gap) point out that KnCl (n = 3, 5, 7) clusters are more stable. The calculated adiabatic ionization energies (AIE) for the KnCl (n = 2–6) clusters are in agreement with the measured ionization energies. The optical properties, namely optical electronegativity and refractive index, depends on the GH-L energy values. The K atom capped planar rhombus geometry of the K4Cl causes the noticeable vibrational frequency shift compared to the rest of IR spectra of the clusters. The first static hyperpolarizability (β o) values are in the range of 2.33 × 103 –2.87 × 104 au and the second static hyperpolarizability varies between 5.74 × 106 au and 38.9 × 106 au for the cluster. The nonlinear optical response is due to the superalkali nature of KnCl (n = 2–7) clusters. From computed β vec values, the hyperpolarizability has projection on the dipole moment vector for the superalkalis except the K2Cl and K5Cl. The absorption spectra point out that KnCl (n = 6–7) clusters can be suitable as a NLO material since they have transparency in the deep UV region (λ< 300 nm).

Ultrahigh Heat/Fire-Resistant, Mechanically Robust, and Closed-Loop Chemical Recyclable Polycarbonate Enabled by Facile Bond Dissociation Energy Modulation.

Plastics serve as an essential foundation in contemporary society. Nevertheless, meeting the rigorous performance demands in advanced applications and addressing their end-of-life disposal are two critical challenges that persist. Here, an innovative and facile method is introduced for the design and scalable production of polycarbonate, a key engineering plastic, simultaneously achieving high performance and closed-loop chemical recyclability. The bisphenol framework of polycarbonate is strategically adjusted from the low-bond-dissociation-energy bisphenol A to high-bond-dissociation-energy 4,4'-dihydroxydiphenyl, in combination with the incorporation of polysiloxane segments. As expected, the enhanced bond dissociation energy endows the polycarbonate with an extremely high glow-wire flammability index surpassing 1025°C, a 0.8mm UL-94V-0 rating, a high LOI value of 39.2%, and more than 50% reduction of heat and smoke release. Furthermore, the π-π stacking interactions within biphenyl structures resulted in a significant enhancement of mechanical strength by as more as 37.7%, and also played a positive role in achieving a lower dielectric constant. Significantly, the copolymer exhibited outstanding closed-loop chemical recyclability, allowing for facile depolymerization into bisphenol monomers and the repolymerized copolymer retains its high heat and fire resistance. This work provides a novel insight in the design of high-performance and closed-loop chemical recyclable polymeric materials.

Cost-efficient sunlight-driven thermoelectric electrolysis over Mo-doped Ni5P4 nanosheets for highly efficient alkaline water/seawater splitting

Thermoelectric water spitting to hydrogen systems has great potential in the production of environment-friendly fuel using renewable solar energy in the future. In this work, we prepared porous nanosheet Mo doping Ni5P4 catalysts on nickel foam with efficient hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance in alkaline media. Density Functional Theory (DFT) calculations and experimental studies have shown that Mo doping deadeneds the interaction between H and O atomic orbitals of transition state water molecules, effectively weakening the activation energy of H2O dissociation. Therefore, Mo doping is favorable for enhancing HER activity with overpotential at 10 mA cm–2 of 93 mV and Tafel slope of 40.1 mV dec–1 in 1 M KOH. Besides, it exhibits high alkaline OER activity with an ultra-low overpotential of 200 mV at 10 mA cm–2. Moreover, this catalyst only needs 1.537 V in a dual-electrode configuration of the electrolytic cell, which is much lower than the commercial Pt/C-RuO2 couple (1.614 V). In addition, we have developed and constructed a solar thermoelectric generator (TEG) that is capable of floating on water. This TEG has a continuous power output and an exceptionally long lifespan, providing a stable power supply to the synthesized catalyst electrolyzer. It can produce a maximum power output of over 90 mW, meeting the requirement of converting solar radiation heat into usable electricity. As a result, the system achieves productivity of 0.11 mL min–1 H2. This solar thermal energy conversion technology shows the possibility of large-scale industrial production of H2 and provides a new idea for exploring heat source utilization.

Theoretical and experimental study of a new antioxidant xanthone: Solvent and intramolecular hydrogen bond effects

Free radicals are harmful reactive species that cause various problems in the human body. Antioxidant compounds, such as xanthones found in natural products, can help prevent these effects. This study focuses on the antioxidant behavior of ravenelin (RVL) and ravenelin B (RVLB), a newly discovered xanthone in the Exserohilum rostratum fungus. Both experimental and in silico tests were conducted, comparing them to ascorbic acid, a standard antioxidant. The results showed that RVL has a lower bond dissociation energy (312 kJ/mol) than ascorbic acid (313 kJ/mol), indicating comparable antioxidant performance. This difference is mild but agrees with the experiment that indicates RVL efficiency is equivalent to ascorbic acid at low concentrations. RVLB, however, demands higher dissociation energy (323 kJ/mol) and consequently it has a lower antioxidative efficiency. Thus, antioxidant capacity is found as RVL>ascorbic acid>RVLB. From experimental assays, the RVL performance was confirmed through experimental tests at different solute concentrations. The study also examines the effects of solvents and intramolecular hydrogen bonds. Ravenelin molecules present three hydroxyl groups involved in intramolecular OH⋯O interactions. However, analysis based on the infrared spectra, as well as Bader's theory and non-covalent interactions done in water solvent showed that the two strongest H-bonds (≈−37 kJ/mol) better stabilize the molecular structure, but are not favorable to antioxidant reactions, indicating that hydrogen scavenging occurs at the less hydrogen-bonded hydroxyl group. The solvent also plays an active role first in facilitating hydrogen abstraction besides changing the hydrogen scavenging mechanism according to the environmental polarizability. Additionally, the antioxidant mechanism of ravenelin molecules changes from nonpolar to polar solvents, allowing for hydrogen abstraction.

Catalytic Asymmetric Access to Structurally Diverse N-Alkoxy Amines via a Kinetic Resolution Strategy.

Chiral N-alkoxy amines are increasingly vital substrates in bioscience. However, asymmetric synthetic strategies for these compounds remain scarce. Catalytic kinetic resolution represents an attractive approach to prepare structurally diverse enantiopure N-alkoxy amines, which has remained elusive due to the notably reduced nucleophilicity of the nitrogen atom together with the low bond dissociation energies of labile NO-C and N-O bonds. We here report a general kinetic resolution of N-alkoxy amines through chemo- and enantioselective oxygenation. The mild and green titanium-catalyzed approach features broad substrate scope (55 examples), noteworthy functional group compatibility, high catalyst turnover number (up to 5200), excellent selectivity factor (s > 150), and scalability.

Multiple Bonding in AeN- (Ae=Ca, Sr, Ba).

Quantum chemical calculations using ab initio methods at the MRCI+Q(8,9)/def2-QZVPPD and CCSD(T)/def2-QZVPPD levels as well as using density functional theory are reported for the diatomic molecules AeN- (Ae=Ca, Sr, Ba). The anions CaN- and SrN- have electronic triplet (3Π) ground states with nearly identical bond dissociation energies De ~57 kcal/mol calculated at the MRCI+Q(8,9)/def2-QZVPPD level. In contrast, the heavier homologue BaN- has a singlet (1Σ+) ground state, which is only 1.1 kcal/mol below the triplet (3Σ-) state. The computed bond dissociation energy of (1Σ+) BaN- is 68.4 kcal/mol. The calculations at the CCSD(T)-full/def2-QZVPPD and BP86-D3(BJ)/def2-QZVPPD levels are in reasonable agreement with the MRCI+Q(8,9)/def2-QZVPPD data, except for the singlet (1Σ+) state, which has a large multireference character. The calculated atomic partial charges given by the CM5, Voronoi and Hirshfeld methods suggest small to medium-sized Ae←N- charge donation for most electronic states. In contrast, the NBO method predicts for all species medium to large Ae→N- electronic charge donation, which is due to the neglect of the (n)p AOs of Ae atoms as genuine valence orbitals. Neither the bond orders nor the bond lengths correlate with the bond dissociation energies. The EDA-NOCV calculations show that the heavier alkaline earth atoms Ca, Sr, Ba use their (n)s and (n-1)d orbitals for covalent bonding.

Modulating Ionic Linkages in the Heterocyclic Sulfated Polysaccharide Carrageenan for Enhanced Selectivity Against Amelanotic Melanoma Cells

AbstractThe present research is the use of Heterocyclic sulfated polysaccharides, exemplified by carrageenan, with the high selective anti‐cancer against melanoma cancer. This study focuses on optimizing the ionic linkage of carrageenan to enhance its selectivity and activity against skin cancer cells with the help of cell line assays and in‐silico studies. The cytotoxicity and selectivity of the optimized derivatives were assessed in‐vitro against skin cancer cells and normal skin cells. The barium‐linked carrageenan demonstrated significantly increased selectivity against skin cancer cells with a selectivity index of 45, however, the reference drug was found with a selectivity index of 23. The selectivity of the compound 3 (Ba ion linked) was analysed through the ion dissociation energy and found that the more energy is require to dissoxiate in the ion, which signifiacnlty absorbs inside the cell because of non‐ionic form. The selectivity sequence of K+&lt;Ca2+&lt;Ba2+ as a targeted anti‐cancer agent. The present research unfold the importance of ion linkage of chromophore, to get the more active and selective compounds, which will be a path to get the ion activity relationship of various drugs without interfering the chromophore. The findings suggest a promising avenue for the development of targeted therapies with the change of ions, emphasizing the potential of heterocyclic sulfated polysaccharides in the field of cancer treatment with enhanced tuning of selectivity. The further scope is the gel formation of the Ba2+ carrageenan which will be the first API (Active Pharmaceuitical Ingredients) based formulation for skin cancer.

New lead barium borate glass system for radiation shielding applications: impacts of copper (II) oxide on physical, mechanical, and gamma-ray attenuation properties

Abstract The current work seeks to develop a novel CuO-doped lead calcium barium borate glass using the melt quenching method at 1100 °C. There was a 3.91–4.49 g/cm3 change in the fabricated glasses’ density, with a respective 0–15 mol.% increase in the CuO concentration. Additionally, substituting CuO for B2O3 reduced the fabricated glasses mechanical properties due to the decreased dissociation energy between 63.99 and 60.50 kcal/cm3, and the packing factor decreased between 15.22 and 13.23 cm3/mol. Through increasing the fabricated glasses’ CuO concentration, there was a decrease in the bulk, longitudinal, shear, and mechanical Young moduli. Moreover, Monte Carlo simulation (energy interval: 0.033–2.506 MeV) was employed to evaluate the fabricated glasses’ ability to shield gamma rays. A 0–15 mol.% increase in the CuO concentration raised the linear attenuation coefficient (LAC) between 14.081 and 16.797 cm−1 (0.059 MeV), 0.325–0.371 cm−1 (0.662 MeV), and 0.154–0.176 cm−1 (2.506 MeV). The LAC enhancement reduced the required half value thickness of the fabricated glasses by 16.2 %, 12.53 %, and 12.85 % at the of 0.059, 0.662, and 2.506 MeV gamma ray energies.