Halogen Molecules Research Articles

Vibrational resonance in bichromatically excited diatomic molecules in a shifted molecular potential.

For bichromatically excited diatomic molecules modeled in a shifted Tietz-Wei molecular potential, we demonstrate the occurrence of vibrational resonance (VR) when a saddle-node (SN) bifurcation takes place and its nonoccurrence in the absence of an SN bifurcation. We have examined the VR phenomenon and its connection with SN bifurcation for eight diatomic molecules, namely, H_{2},N_{2},Cl_{2},I_{2},O_{2}, HF, CO, and NO, consisting of homogeneous, heterogenous, and halogen molecules. We demonstrate that each of them vibrates at a distinct resonant frequency but with a spread in frequency. The high-frequency amplitude at which VR occurs corresponds to the SN-bifurcation point. We validate our analytic results by numerical simulations and show that the homonuclear halogens respond only weakly to bichromatic fields, which may perhaps be linked to their absence of SN bifurcation.

Molecular study of an improved Wei energy potential for the halogens and gallium halides

An improved Wei potential energy function as a molecular potential model has not been widely reported probably due to its physical structure. In this study, the Feinberg–Horodecki (FH) equation is examined for the improved Wei energy potential function. To validate the calculations, the Feinberg–Horodecki equation is transformed into an energy equation by putting c=1, and Pn=En. Numerical results are generated for some molecules using the energy equation and the molecular spectroscopic constants for λ=-0.1,0, and 0.1. The predicted results for the energy eigenvalues are compared with the experimental data for four halogen molecules and four gallium halides. The results revealed that the negative values of λ do not produce values that align with the experimental data. It is also shown that the result obtained with λ=0 reproduces a better result for the improved Wei potential energy function than the result obtained with λ=0.1.

Electronic and adsorption properties of halogen molecule X2 (X=F, Cl) adsorbed arsenene: First-principles study

The geometry, electronic structure, and adsorption properties of halogen molecule X2(X = F, Cl) on arsenene were investigated using first-principles calculations. The adsorption of molecules was considered at various sites and in various orientations on the pristine arsenene (p-As) surface. Both molecules show chemisorption and the crystal orbital Hamiltonian population (COHP) analysis reveals the formation of strong X-As bonds. In particular, the adsorbed molecules spontaneously dissociate into atomic halogen atoms, with a diffusion barrier of 1.91 (1.72) eV for F2(Cl2). The adsorbed X2 molecules induced distortions in the local geometry due to strong interaction with arsenene. Importantly, the formation of X-As bonding remarkably changed the electronic properties, evidenced by the decrease of the actual band gap due to the emergence of defect states within the band gap. For instance, the F2 adsorbed arsenene system (F2-As) exhibited an average band gap of 1.17 eV, and Cl2 adsorbed arsenene (Cl2-As) showed an average band gap of 0.83 eV. In particular, indirect to direct band gap transition was observed for some adsorption configurations. The reduction in band gap resulted in the enhancement of electrical conductivity. These findings suggest that the electronic properties of arsenene can be tuned by halogen decoration.

Product State-Resolved Reactive Scattering Studies of the H + Cl2 (v0 = 1-3, j0 = 0) → HCl + Cl Reaction by the Time-Dependent Wave Packet Method.

The typical hydrogen atom plus halogen molecule reaction H + Cl2 → HCl + Cl has implications across many fields. In this paper, product state-resolved quantum dynamics calculations for the vibrationally excited reaction H + Cl2 (v0 = 1-3, j0 = 0) → HCl + Cl were conducted using the time-dependent wave packet method on a newly developed accurate potential energy surface. Numerical results indicate that the initial vibrational excitation of Cl2 does enhance the reactivity for this early barrier reaction, although less than the enhancement of the translational energy. The calculated product vibrational state-resolved integral cross sections and rate constants reveal that the product vibrational state distribution and the initial vibrational state of Cl2 are highly correlated. The thermal rate constant in the temperature range from 100 to 1000 K was given and is found to be in reasonable agreement with the experimental measurements.

Mathematical modeling of non-linear reaction-diffusion process in autocatalytic reaction: Akbari-Ganji method

A theoretical model of the electroreduction of halogen oxoanions via autocatalytic redox mediation by halide anions is discussed. This autocatalytic process depends upon a system reaction-diffusion equation including a nonlinear term for homogeneous reactions. This study solves these equations using the robust and user-friendly analytical technique, the Akbari-Ganji method. The current and the redox component concentration are presented in terms of the rate constant. The influence of variables on current is examined using sensitivity analysis. The most important factor affecting current is the ratio between the bulk concentrations of halogen molecules and non-electroactive halogen oxoanions. The theoretically predicted results are compared with the numerical results. These approximate results enhance our understanding of system behavior.

σ-Hole Site-Based Interactions within Hypervalent Pnicogen, Halogen, and Aerogen-Bearing Molecules with Lewis Bases: A Comparative Study.

σ-Hole site-based interactions in the trigonal bipyramidal geometrical structure of hypervalent pnicogen, halogen, and aerogen-bearing molecules with pyridine and NCH Lewis bases (LBs) were comparatively examined. In this respect, the ZF5···, XF3O2···, and AeF2O3···LB complexes (where Z = As, Sb; X = Br, I; Ae = Kr, Xe; and LB = pyridine and NCH) were investigated. The electrostatic potential (EP) analysis affirmations outlined the occurrence of σ-holes on the systems under consideration with disparate magnitudes that increased according to the following order: AeF2O3 < XF3O2 < ZF5. In line with EP outcomes, the proficiency of σ-hole site-based interactions increased as the atomic size of the central atom increased with a higher favorability for the pyridine-based complexes over NCH-based ones. The interaction energy showed the most favorable negative values of -35.97, -44.53, and -56.06 kcal/mol for the XeF2O3···, IF3O2···, and SbF5···pyridine complexes, respectively. The preferentiality pattern of the studied interactions could be explained as a consequence of (i) the dramatic rearrangement of ZF5 molecules from the trigonal bipyramid geometry to the square pyramidal one, (ii) the significant and tiny deformation energy in the case of the interaction of XF3O2 molecules with pyridine and NCH, respectively, and (iii) the absence of geometrical deformation within the AeF2O3···pyridine and ···NCH complexes other than the XeF2O3···pyridine one. Quantum theory of atoms in molecules and noncovalent interaction index findings reveal the partially covalent nature of most of the investigated interactions. Symmetry-adapted perturbation theory affirmations declared that the electrostatic component was the driving force beyond the occurrence of the considered interactions. The obtained findings will help in improving our understanding of the effect of geometrical deformation on intermolecular interactions.

Structural, Electronic and Vibrational Properties of B24N24 Nanocapsules: Novel Anodes for Magnesium Batteries

We report on DFT-TDDFT studies of the structural, electronic and vibrational properties of B24N24 nanocapsules and the effect of encapsulation of homonuclear diatomic halogens (Cl2, Br2 and I2) and chalcogens (S2 and Se2) on the interaction of the B24N24 nanocapsules with the divalent magnesium cation. In particular, to foretell whether these BN nanostructures could be proper negative electrodes for magnesium-ion batteries, the structural, vibrational and electronic properties, as well as the interaction energy and the cell voltage, which is important for applications, have been computed for each system, highlighting their differences and similarities. The encapsulation of halogen and chalcogen diatomic molecules increases the cell voltage, with an effect enhanced down groups 16 and 17 of the periodic table, leading to better performing anodes and fulfilling a remarkable cell voltage of 3.61 V for the iodine-encapsulated system.

Is There the Fourth Law of the Thermodynamics?

The Gibbs energy change ∆ G in half-reactions Me →Me n+ + ne and halogens 1/2Hal2 + e → Hal- were analyzed using cycles∆ G Me = ∆ G subl. + ∑ I - ∆ G hydr. - W e (1)∆ G Hal = ∆G dissoc. - E affinity - ∆ G hydr. + W e (2)including energies of metal sublimation +∆G subl. , ionization of metal vapor +∑I , chemical hydration of Me n+ ions -∆G hydr. , condensation of free electrons from vacuum onto electrode - W e ; dissociation of halogen molecules + ∆G dissoc. , acceptance of electrons from vacuum by halogens - E affinity, chemical hydration of Hal- anions -∆G hydr. , abstraction of electrons from electrode into vacuum + W e. [1,2].The Gibbs energy ∆G* Me and ∆G* Hal were calculated using known constants Eqns. (3, 4) [1]∆ G* Me = ∆ G subl. + ∑ I - ∆ G hydr. (3)∆ G* Hal = 1/2 ∆ G dissoc. - E affinity - ∆ G hydr. (4)The relations between ∆G*/ n by Eqns. (3), (4), n - number of electrons, for metals and halogens (electron bonds decrease in them) and corresponding standard potentials Eo are linear and extrapolated to Eo = - 4.72 V SHE at ∆G*/ n = 0 (Fig.1;lines 1, 2).Calculated ∆G*/ n = 4.95 eV (Cu)and ∆G* = -5.27 eV (I2 ) are close in value (Fig.1). According to Eqns. (1, 2), ∆G/ n in half-reactions of weak reductant Cu and oxidant I 2 should tend to zero (metals - non-metals transition).For this, calculated ∆G* = 4.95 eV (Cu)and ∆G* = -5.27 eV (I2 ) should be decreased and increased on W e ~ 5.1 - 5.2 eV respectively [1,2].The intermediate W e,interm. = 5.19 eV is determined to some substance (metals - non-metals transition) which electrons should be bound by non-specific (non-chemical) definite Coulomb bond [2, 3].The linear relations for metals (line 1) and halogen (line 2) are displaced in the parallel direction by -5.19 and 5.19 eV respectively (Fig.1) when account is taken W e,interm. = 5.19 eV, i.e., we obtained linear relations 1’ and 2’ between ∆G/ n of chemical half-reactions by Eqns. (1, 2) and their Eo . Relations 1’ and 2’ intersect with E o – axis at ∆G/ n = 0 at potential Eo = ~ + 0.47 V SHE close to Billiter potential + 0.475 V SHE corresponded by [1-3] to hypothetical electrode between metals and non-metals without own chemical activity or to chemical equilibrium half-reactions.According to Eqns. (3, 4), limiting separated electrons (vacuum) and ions without any bonding are formed from metals, non-metals with spending decreased ∆G*/ n (lines 1, 2, Fig.1). When ∆G*/ n = 0 ( Eo = - 4.72 V SHE), all components of Eqns. (3) and (4) are degenerated. For such a system ∆G* = - A max = 0, the entropy change is equal ∆ S = 0. Hence, the entropy S tends to constant and infinity S max → ∞.The Gibbs energy ∆G*/ n = 5.19 eV (Fig.1)of limiting separation of definite Coulomb bound electrons – ions (transfer + 0.475 V SHE → - 4.72 V SHE) per electron5.19 eV x 1.6021 x 10-19 J/eV = 8.314899 x 10-19 J (5)and the gas constant R = 8.31441 J/mol.K have equal bases.Then, R = 8.3144 J/mol. K is sufficient for limiting separation per 1 K of 1019 such non-chemically bound electrons - ions ( W e,interm. = 5.19 eV; Eo = + 0.475 V SHE, Fig.1). These electrons - ions should be analogous to non - chemically interacting particles of ideal gas at STP conditions.The energy R Δ T is equal to the energy 5.19 eV = 500703.548 J/mol of limiting separation of definite Coulomb bound electrons – ions at the change of temperature Δ T Δ T = 5.19 eV / 8.3144 J/mol K = 500703.548 J/mol / 8.3144 J/mol K = = 60221.25 K (6)which the base corresponds to Avogadro number and mole of limiting separated electrons – ions is equal to6.022 . 104 K x 1019 mol-1 K-1 = 6.022.1023 mol-1 (7)Hence, the origin of Avogadro number is number of electrons - ions condensing from limiting separated state (without bonding) to their state with non-chemical definite Coulomb bonds (analogous ideal gas).The 4th thermodynamics law: limiting separated state of electrons - ions with entropy S max →∞ occurs with increasing temperature on Δ T = 6.022 . 104 K from STP, at 6.022. 104 oC. The released heat leads only to increase in kinetic energy and temperature of limiting separated electrons - ions.Reference1.A.I.Chernomorskii, Zh. Fiz. Khim., 52, 757 (1978).2.A.I.Chernomorkii, The Intermediate Electron Bond and Half-reactions (Scientific Resources, New Yopk, NY) (1999).3.A.I.Chernomorkii, Journal of The Electrochemical Society, 2021,168, 116514. Figure 1

A Cd-based MOF crystal vessel for the synthesis of interhalogens

As important halogenating and oxidant agents, the synthesis and utilization of interhalogens are plagued by their purity problem, strong volatility and high reactivity. Herein, a flexible Cd-based metal-organic framework (MOF), {[Cd(1,4-bdc)(4-bpa)]·DMF}n (1, where 4-bpa = 1,2-bis(4-pyridyl)acetylene), was prepared and its corresponding activation species, [Cd(1,4-bdc)(4-bpa)]n (2), with moderate pore size and shape, acting as a crystal vessel, was applied to synthesize and store pure interhalogens. The synthesis of interhalogen was realized by quantitive transformation of halogen molecules incorporated in the pores of 2, which was confirmed by single-crystal X-ray diffraction and other structural characterizations. The embedded interhalogen molecules were stabilized by their interactions with the inner groups of the porous framework of 2 and released in polar solvent and utilized in iodocyclization of organic alcohols with high selectivity. This work not only opens a new door to the synthesis of pure interhalogens but also demonstrates powerful applications of MOF crystal vessels in realizing classic but important inorganic and organic reactions.

Antibacterial Activities and Life Cycle Stages of Asparagopsis armata: Implications of the Metabolome and Microbiome.

The red alga Asparagopsis armata is a species with a haplodiplophasic life cycle alternating between morphologically distinct stages. The species is known for its various biological activities linked to the production of halogenated compounds, which are described as having several roles for the algae such as the control of epiphytic bacterial communities. Several studies have reported differences in targeted halogenated compounds (using gas chromatography-mass spectrometry analysis (GC-MS)) and antibacterial activities between the tetrasporophyte and the gametophyte stages. To enlarge this picture, we analysed the metabolome (using liquid chromatography-mass spectrometry (LC-MS)), the antibacterial activity and the bacterial communities associated with several stages of the life cycle of A. armata: gametophytes, tetrasporophytes and female gametophytes with developed cystocarps. Our results revealed that the relative abundance of several halogenated molecules including dibromoacetic acid and some more halogenated molecules fluctuated depending on the different stages of the algae. The antibacterial activity of the tetrasporophyte extract was significantly higher than that of the extracts of the other two stages. Several highly halogenated compounds, which discriminate algal stages, were identified as candidate molecules responsible for the observed variation in antibacterial activity. The tetrasporophyte also harboured a significantly higher specific bacterial diversity, which is associated with a different bacterial community composition than the other two stages. This study provides elements that could help in understanding the processes that take place throughout the life cycle of A. armata with different potential energy investments between the development of reproductive elements, the production of halogenated molecules and the dynamics of bacterial communities.

Porous pentagraphene nanotube halogen gas sensor: a first principles study

The recent technological revolution in nanoscience has created a huge potential to build highly sensitive, low-cost and power efficient portable sensors. Here, we have investigated the novel nano-porous penta-graphene nanotube (PGNT) device for detection and separation of halogen gases like fluorine (F2), chlorine (Cl2), bromine (Br2) and iodine (I2). The host carbon atoms are selectively removed to create the nanopores on the tube surface. 1, 2, 3 and 4 host carbon atoms are removed from the surface to create vacancies which were then investigated for detection and separation of halogen gases using functionalisation of pore edges. The I-V measurements were performed to establish the gas detection application of these novel porous structures. Furthermore, interaction energy graphs were obtained which show efficient separation of various halogen molecules by functionalising the pores with F2, Cl2 and H atoms.

Development of a multiblock metabolomics approach to explore metabolite variations of two algae of the genus Asparagopsis linked to interspecies and temporal factors

Metabolomics, the science that describes a full range of small molecules in a sample at a time point, is a powerful tool to evaluate patterns in metabolite variations affected by environmental factors. We developed a multiblock metabolomics approach using LC-HRMS, HS-SPME-GC–MS and 1H NMR to study the interspecies and temporal metabolites variations of two red algae species from the genus Asparagopsis well-known for their broad range of biological activities. Samples were collected over two years at 5 sites. For each sample, a biphasic extraction was performed to allow distinct analyses of apolar phases by LC-HRMS and of polar phases by 1H NMR. The remaining lyophilized algal powder was analysed using a HS-SPME-GC–MS method. Temporal variation of antibacterial activities of extracts of the two algae was also studied and its potential covariation with algal metabolome was evaluated. On the one hand, the multiblock analysis allowed the interspecies and temporal discrimination of the two species, and putative identification of potential chemotaxonomic markers including highly halogenated molecules. Organosulfur compounds enriched in A. armata samples could be detected with both 1H NMR (taurine and isethionic acid) and LC-HRMS (sulfolipids). On the other hand, the variation in several metabolites intensities could be related to temporal effects, probably linked to environmental factors. It is the case of floridoside, a major carbohydrate, and citrulline (1H NMR) that both can have antioxidant properties, but also of various sulfolipids (LC-HRMS). The antibacterial activity of extracts of both species was constant throughout the year and did not covary with metabolome. This work is also the first to report the study of the metabolome of the two different species of the genus Asparagopsis by 1H NMR and HS-SPME-GC–MS.

Effects of Reynolds number and solidity ratio on advection dominated mixing in a high-altitude instrument

Due to the role of ClO and BrO in the rate-limiting step of the catalytic cycles enabling ozone loss, measurement of concentrations of these halogen molecules is of critical importance to understanding the loss rate of ozone in the stratosphere. A key advantage of in situ measurements is that these rate-limiting molecules can be observed simultaneously with ozone in the same volume element of the stratosphere, with high spatial and temporal resolution. Historically, these in situ measurements were made using instruments on the NASA ER-2 flight platform for a few hours at a time. However, the development and advancement of a high-altitude long-endurance (HALE) solar aircraft has made it possible to monitor these radicals continuously in the stratosphere. The slower flight speeds of the HALE aircraft will greatly improve molecule detection sensitivity and spatial resolution. To ensure proper mixing and accurate measurements, a quantitative dissection of the flow dynamics within the instrument architecture is required. Of particular importance are the turbulent behavior and the boundary layer growth, both of which affect measurement quality. The geometry of the NO injector used for titration is studied as a function of its solidity and the flight airspeed, to understand its effect on turbulence and boundary layer growth. A 3D Computational Fluid Dynamics simulation of an Eulerian mixture model is used to analyze the advection-dominated mixing inside the instrument. The injector inside the instrument is found to act as a flow-conditioning device, with a lower solidity causing the downstream flow to be increasingly turbulent. Additionally, a quantitative relationship between the Reynolds number of the inlet air and the volume fraction of the flow is demonstrated. Analysis of the boundary layer dependencies demonstrates that the boundary layer does not encroach on the optical sensing area in any of the cases.

Bound exciton luminescence and phonon sideband analysis of iodine intercalated bulk 2H-MoSe2 crystals

Temperature dependence of the luminescence spectra of MoSe2 crystals intercalated with I2 molecules has been investigated in the temperature range 11–100 K. The spectrum of luminescence, which is caused by the recombination of excitons bound on iodine molecules embedded in the van der Waals gap (vdW), consists of zero-phonon doublet at an energy less by 0.1 eV than the width of the indirect band gap of the host crystal, and its phonon replicas. The distance between the spectral lines of this A-B doublet constitutes Δ AB =5.6 meV. From the temperature dependence of the ratio of the A and B lines intensities, it was found, that the rate of radiative recombination of the exciton state B, which is responsible for the short-wavelength line B (EB = 1.0416 eV), is 76 times higher than the recombination rate of the A state (EA = .0360 eV). Based on a comparative analysis of the structure of the luminescence spectra at different temperatures and the measured Raman spectra, it is shown that the observed nine peaks of the phonon sideband are formed by only two vibrational modes with frequencies νph1 = 144 cm−1 and νph2 = 190 cm−1. The 1st frequency corresponds to the vibrational mode due to the second-order Raman process, and the 2nd – to the local vibrational mode induced by the halogen molecule embedded in the layered crystal structure. Finally, fundamental possibilities provided by the intercalation of halogen molecules in the interface of the van der Waals heterojunctions to modify their electronic properties are considered.

High Refractive Index Polymer Thin Films by Charge-Transfer Complexation.

High refractive index polymers are essential in next-generation flexible optical and optoelectronic devices. This paper describes a simple synthetic method to prepare polymeric optical coatings possessing high refractive indexes. Poly(4-vinylpyridine) (P4VP) thin films prepared using initiated chemical vapor deposition are exposed to highly polarizable halogen molecules to form stable charge-transfer complexes: P4VP-IX (X = I, Br, and Cl). Fourier transform infrared spectroscopy was used to confirm the formation of charge-transfer complexes. Characterized by spectroscopic ellipsometry, the maximum refractive index of 2.08 at 587.6 nm is obtained for P4VP-I2. For P4VP-IBr and P4VP-ICl, the maximum refractive indexes are 1.849 and 1.774, respectively. By controlling the concentration of charge-transfer complexes, either through the halogen incorporation step or polymer composition through copolymerization with ethylene glycol dimethacrylate, the refractive indexes of the polymer thin films can be precisely controlled. The feasibility of P4VP-IX materials as optical coatings is also explored. The refractive index and thickness uniformity of a P4VP-I2 film over a 10 mm diameter circular area were characterized, showing standard deviations of 0.0769 and 1.91%, respectively.

Fluorescence Detection of Trace Disinfection Byproducts by Ag Nanoprism-Modulated Lanthanide MOFs

Disinfection byproducts (DBPs), as an emerging water pollutant, present increasing concern and risk in public health and water safety. Due to their low concentration levels and inherent similarity in molecular structures, sensitive and accurate determination of DBPs is still a challenge especially for onsite or online detection. Herein, a self-regulated fluorescent probe based on the Ag nanoprism-modified lanthanide metal-organic framework (AgNPR@EuMOF) is designed for trichloroacetic acid (TCAA) detection. The EuMOF is constructed with Eu as the metal node and 5-boronoisophthalic acid as the ligand. By introducing sulfhydryl groups into EuMOF, AgNPR can be anchored on the EuMOF surface through Ag-S bonds, enabling the synthesis of stable AgNPR@EuMOF composites. During the sensing process, the triangle AgNPR will react with the organic halogen molecule, accomplished with the blue shift of surface plasmon resonance absorption peak and the significant change in the fluorescence of EuMOF. This probe can detect TCAA in a wide concentration range (0.1-40 μM) with high sensitivity and specificity. The density functional theory calculation on binding energies between DBPs and AgNPR suggests that TCAA has the largest interaction ability with AgNPR than other DBPs. Moreover, the detection of TCAA in real tap water and swimming pool water is also demonstrated with high accuracy. The reported AgNPR@EuMOF represents one of the pioneer fluorescence probes in DBP detection, which holds great promise for onsite or online analysis of trace DBPs in water.

Combining machine learning algorithm to improve prediction performance of ab initio method for vibrational energy spectra of HF/HBr/H&lt;sup&gt;35&lt;/sup&gt;Cl/Na&lt;sup&gt;35&lt;/sup&gt;Cl

Halides play an important role in atmospheric chemistry, corrosion of steel, and also in controlling the abundance of O&lt;sub&gt;3&lt;/sub&gt;. Moreover high-precision vibrational energy spectra contain a large amount of quantum information of molecular system and are basic data for people to understand and manipulate molecules. At present, ab-initio methods have achieved many calculation results of the potential energy surfaces and corresponding vibrational energy of molecules, but they still face challenges in terms of accuracy and computational cost. Recently, data-driven machine learning methods have demonstrated very strong capability of extracting high-dimensional functional relationships from massive data and have been widely used in spectrum studies. ​Therefore, a theoretical approach to combining ab-initio method and machine learning algorithm is presented here to predict the vibrational energy of diatomic systems, which improves the accuracy and simultaneously reduces the computational cost. Firstly, the vibrational energy levels of 42 diatomic molecules are obtained by using different CCSD(T) methods to calculate the configurations from simple to complex and the corresponding experimental results are also collected. ​A machine learning algorithm is then used to learn the difference between the CCSD(T) method calculated vibrational results and the experimental vibrational results, and a high-dimensional error function is finally constructed to improve the original CCSD(T) computational accuracy. The results for HF, HBr, H&lt;sup&gt;35&lt;/sup&gt;Cl and Na&lt;sup&gt;35&lt;/sup&gt;Cl (they did not appear in the training set) and other halogen molecules show that compared with the CCSD(T)/cc-pV5Z calculation method alone, the present method reduces the prediction error by more than 50% and the computational cost by nearly one order of magnitude. It is worth noting that the method proposed in this paper is not only limited to the energy level prediction of diatomic systems, but also applicable in other fields where data can be obtained by ab initio methods and experimental methods simultaneously, such as the energy spectrum properties of macromolecular systems.

Energies of some halogen molecules for the improved Tietz potential model

A solution of the radial Schrödinger equation for an improved Tietz potential function was obtained using the concept of the supersymmetric approach. The energy equation obtained for the non-relativistic wave equation was used to generate numerical values for chlorine dimer, iodine dimer and bromine dimer with the aid of their respective spectroscopic constants. The calculated results were compared with RKR values for each of the molecules. The calculated results were found to be in excellent agreement with the RKR values.

Gate Opening without Volume Change Triggers Cooperative Gas Interactions, Underpins an Isotherm Step in Metal-Organic Frameworks.

Three halogenated metal-organic frameworks (MOFs) reported recently exhibited a second step in their CO2 gas adsorption isotherms. The emergence of halogen-bonding interactions beyond a threshold gas pressure between the framework halogen and the CO2 guest was conjectured to be the underlying reason for the additional step in the isotherm. Our investigation employing periodic density functional theory calculations did not show significant interactions between the halogen and CO2 molecules. Further, using a combination of DFT-based ab initio molecular dynamics and grand canonical Monte Carlo simulations, we find that the increased separation of framework nitrate pairs facing each other across the pore channel enables the accommodation of an additional CO2 molecule which is further stabilized by cooperative interactions─an observation that facilely explains the second isotherm step. The increased separation between the nitrate groups can occur without any lattice expansion, consistent with experiments. The results point to a structural feature to achieve this isotherm step in MOFs that neither possess large pores nor exhibit large-scale structural changes such as breathing.

Versatile, Rapid, and Plasma‐Assisted Synthesis of Cuprous Halide Composites at Room Temperature and Pressure (Adv. Mater. Technol. 4/2022)

Liquid Halogenated Molecules Under exposure to atmospheric pressure dielectric barrier discharge plasma, liquid halogenated molecules react on a copper surface to form cuprous halide (CuX) nanocrystals with a composition defined by the halogens in the precursor molecule, enabling a range of CuX products through a rapid, simple process by Jennifer MacLeod and coworkers in article number 2100509.