I2 Molecules Research Articles

In Situ Confined Synthesis of a Copper-Encapsulated Silicalite-1 Zeolite for Highly Efficient Iodine Capture.

Effective capture of radioactive iodine is highly desirable for decontamination purposes in spent fuel reprocessing. Cu-based adsorbents with a low cost and high chemical affinity for I2 molecules act as a decent candidate for iodine elimination, but the low utilization and stability remain a significant challenge. Herein, a facile in situ confined synthesis strategy is developed to design and synthesize a copper-encapsulated flaky silicalite-1 (Cu@FSL-1) zeolite with a thickness of ≤300 nm. The maximum iodine uptake capacity of Cu@FSL-1 can reach 625 mg g-1 within 45 min, which is 2 times higher than that of a commercial silver-exchanged zeolite even after nitric acid and NOX treatment. The Cu nanoparticles (NPs) confined within the zeolite exert superior iodine adsorption and immobilization properties as well as high stability and fast adsorption kinetics endowed by the all-silica zeolite matrix. This study provides new insight into the design and controlled synthesis of zeolite-confined metal adsorbents for efficient iodine capture from gaseous radioactive streams.

Photoionization and Photofragmentation Dynamics of I2 in Intense Laser Fields: A Velocity-Map Imaging Study.

The photoionization and photofragmentation dynamics of I2 in intense femtosecond near-infrared laser fields were studied using velocity-map imaging of cations, electrons, and anions. A series of photofragmentation pathways originating from different cationic electronic states were observed following single ionization, leading to I+ fragments with distinct kinetic energies, which could not be resolved in previous studies. Photoelectron spectra indicate that these high-lying dissociative states are primarily produced through nonresonant ionization from several molecular orbitals (MO) of the neutral. The photoelectron spectra also show clear signatures of resonant ionization pathways (Freeman resonances) to low-lying bound ionic states via Rydberg states of the neutral moiety. To investigate the role of these Rydberg states further, we imaged anionic products (I-) formed through ion-pair dissociations of neutral molecules excited to these Rydberg states by the intense femtosecond laser pulse. Collectively, these results shed significant new light on the complex dynamics of I2 molecules in intense laser fields and on the important role of neutral Rydberg states in a full description of strong-field phenomena in molecules.

Relativistic solutions of the morse potential via the formula method

The Dirac equation is solved using the Formula method. A non-relativistic mapping gives energy eigenvalues, in this limit, for a Hamiltonian including the Morse potential. The energies of the H2, LiH, HCl, CO, ScH, ScN, ScF and I2 molecules for both low and high-lying states are computed. Our results are found to be consistent with the literature. Also, new high-lying states for the Morse potential are also reported in the present study. The results of this study indicate that for the energy Eigen values of the H2 molecule, the deviation from the literature becomes more pronounced for the states (n, l) = (5, 20) and (6, 20).

Ultramicroelectrode Based Approaches to Diagnose Utility of Redox Electrolytes in Flow Batteries

Redox flow batteries are of potential importance to both large scale energy storage and powering the electrical vehicle. Among critical challenges are low volumetric energy density of redox electrolytes, high cost and the maintenance limitations that greatly impede the wide application of conventional flow batteries. In this respect, the redox-active charge-storage material has a significant impact on the performance of a flow battery. The concentration of redox centers and their reaction kinetics have an influence on the available current densities and, thus, the power of the device.Many inorganic and organic electroactive systems have been proposed as alternatives to vanadium species in redox flow batteries. In the study, we explore the concept of highly concentrated solutions of such redox systems as iodine/iodide and poloxometallates of molybdenum and tungsten, and the possibility of optimizing their performance to exhibit high rates of charge propagation. While the iodine/iodide system can be prepared at high concentrations, the polyoxometallates of molybdenum and tungsten can serve as model examples of multi-electron systems for all-liquid redox flow batteries and related fundamental investigations. Reactions in the zinc/iodine (polyiodide) redox flow battery are as follows: Zn → Zn2+ + 2e- (E = −0.76 V vs SHE) at the negative electrode (anode), and 3I- → I3 − + 2e− (E = 0.54 V vs SHE) at the positive electrode (cathode) thus yielding a total theoretical potential output as high as ∼1.3 V. The increase of current density could be achieved not only by reducing the viscosity of the electrolyte, thus accelerating charge-carrier transport, but also – by referencing to our experience with the iodine/iodide couple as charge relay for dye-sensitized solar cells – through improvement of the dynamics of charge propagation in highly concentrated iodine/iodide solution via the catalyzed enhancement of rates of electron self-exchange (hopping) between iodine/iodide (polyiodide) redox species as well as by accelerating the interfacial kinetics at electrodes. This can be realized by choosing appropriate electrode materials and through their activation or modification. The electrochemical activities of the redox couples are usually significantly increased through application of nanostructured functionalized carbons. While dispersed in solutions they can improve electron transfers to the redox sites. The proposed chemistry has been first tested using the microelectrode methodology to determine mass-transport (effectively diffusional) coefficients for charge propagation, heterogeneous and homogeneous (electron self-exchange) rates of electron transfers. Unless catalyzed, both interfacial and bulk (self-exchange) electron transfers involving the iodine/iodide redox system are somewhat complicated; there is a need to break the I-I bond in the I3 -or I2 molecule; it has also been well-established that platinum (e.g. when deposited on the counter electrode) induces electron transfers within the iodine/iodide redox system. As far as heteropolyacids are concerned, they exhibit very strong Brønsted acidity, act as proton conductors, and undergo fast, reversible, multi-electron electron transfers leading to the formation of highly conducting, mixed-valence (e.g. tungsten(VI,V) or molybdenum(VI,V) heteropoly blue) compounds. The polyoxometallate-based redox electrolytes have different chemical identities, and they could be considered as anolytes or catholytes, depending on their redox potentials but, typically, their use would require formation of an asymmetric system with different-type redox species.While dynamics of electrochemical processes has an influence on the systems’ current densities, the viscosity of the electrolyte and the mass transport dynamics are also affected by the choice of the redox-active material and its concentration. Trying to develop useful electroanalytical diagnostic criteria, we are going to extend the historical concepts of charge propagation in semi-solid or semi-liquid systems developed for mixed-valence redox polymers and polynuclear materials to the development of redox electrolytes. Fundamental electroanalytical approaches utilizing ultramicrodisk electrodes and interdigitated arrays will be adapted to characterization of redox electrolytes.

A sustainable gel-state ionic liquid-based dye-sensitized solar cell with a novel synthesized lansoprazole functionalized graphene oxide

Using environmental-friendly ionic liquid-based (IL) composite electrolytes to assemble gel-DSSC can restrict volatile organic solvent electrolyte leakage and improve device flexibility and sustainability. Through a covalent functionalization technique, a new class of 2- {(3-methyl-4-(2, 2, 2-trifluoroethoxy) pyridin-2-yl) methylsulfinyl}-1H-benzo(d)imidazole (lansoprazole, LNS) was covalently grafted onto graphene oxide sheets (GO). The incorporation of GO-LNS nanofillers could enhance the redox couple diffusion and conductivity of IL-based electrolytes due to the increased number of electronic and spatial active sites of mobile defects of GO by electron-rich nitrogen, oxygen, and sulphur heteroatoms. A gel-DSSC device fabricated with optimized GO-LNS/IL showed nearly 93% higher ionic conductivity and almost less than twice charge transfer resistance compared to the device made with standard IL-based electrolyte. The excellent electronic properties of GO-LNS containing electrolytes developed the photoelectrochemical characterization considerably. Thus, the overall performance of the gel-DSSC devices showed the maximum power conversion efficiency of 7.158% instead of 3.127% for the bare IL-based electrolyte. Such excellent efficiency correlating with the induced N, S, O, and F atoms localized at the LNS functional group can change the electronic states of graphitic carbon, which results in active sites for catalyzing I3− to I− decrease. On the other hand, fluorine atoms in the trifluoroethoxy group can provide binding sites for I2 molecules. This covalent modification of GO with lansoprazole assembly may develop effective strategies for practical application through an advanced class of environmentally friendly and sustainably produced IL-based nanocomposites.

Superior Iodine Uptake Capacity Enabled by an Open Metal-Sulfide Framework Composed of Three Types of Active Sites

Superior Iodine Uptake Capacity Enabled by an Open Metal-Sulfide Framework Composed of Three Types of Active Sites

(Invited) Charge Propagation in Highly Concentrated Iodine/Iodide Solutions As Potential Electrolytes for Redox Flow Batteries

The technology of Redox Flow Batteries is an important option to store energy from the operating irregularly renewable energy sources. The perspectives concern stationary energy storage, including grid-scale energy storage, thanks to their high power performance, flexible design, and ease of scaling-up. The flow-based electrochemical energy storage systems utilize the appropriate electroactive species dissolved in externally flowing electrolytes which are ready to accumulate all (or part) of the charge. Among important issues is the search for highly efficient (i.e., capable of fast electron transfers) electroactive systems that would yield high power and energy densities during the systems’ operation.In the present work, we concentrate on utilization of highly concentrated iodine/iodide redox systems and their possibility to exhibit high rates of charge propagation. In practical terms, it can be combined with ZnI2, or other zinc salt, containing electrolyte. Reactions in the zinc/iodine (polyiodide) redox flow battery are as follows: Zn → Zn2+ + 2e- (E = −0.76 V vs SHE) at the negative electrode (anode), and 3I- → I3 − + 2e− (E = 0.54 V vs SHE) at the positive electrode (cathode) thus yielding a total theoretical potential output as high as ∼1.3 V. The increase of current density could be achieved not only by reducing the viscosity of the electrolyte, thus accelerating charge-carrier transport, but also – by referencing to my experience with the iodine/iodide couple as charge relay for dye-sensitized solar cells – through improvement of the dynamics of charge propagation in highly concentrated iodine/iodide solution via the catalyzed enhancement of rates of electron self-exchange (hopping) between iodine/iodide (polyiodide) redox species as well as by accelerating the interfacial kinetics at electrodes. This can be realized by choosing appropriate electrode materials and through their activation or modification. The electrochemical activities of the redox couples are usually significantly increased through application of nanostructured functionalized carbons. While dispersed in solutions they can improve electron transfers to the redox sites. The proposed chemistry has been first tested using the microelectrode methodology to determine mass-transport (effectively diffusional) coefficients for charge propagation, heterogeneous and homogeneous (electron self-exchange) rates of electron transfers. Unless catalyzed, both interfacial and bulk (self-exchange) electron transfers involving the iodine/iodide redox system are somewhat complicated; there is a need to break the I-I bond in the I3 -or I2 molecule; it has also been well-established that platinum (e.g. when deposited on the counter electrode) induces electron transfers within the iodine/iodide redox system [1]. In the presentation, we are going to explore the respective interfacial (electrocatalytic) phenomena on nanostructured metal oxides (e.g. zirconia), in addition to traces of expensive platinum or palladium nanoparticles (provided that catalytic centers are three-dimensionally distributed in the electrolyte phase), and we will utilize them to enhance iodine/iodide electron transfers to develop a new generation of redox mediators or ultra-fast components of redox electrolytes. Our results show that the catalyzed iodine/iodide system can reach extremely high electron self-exchange rates, namely on the level of 109 – 1010 mol-1 dm3 s-1 . [1] I.A. Rutkowska I.A., M. Marszalek, J. Orlowska, W. Ozimek, S.M. Zakeeruddin, P.J. Kulesza, M. Grätzel, ChemSusChem 8 (2015) 2560-2568.

Iodine Uptake by Zr-/Hf-Based UiO-66 Materials: The Influence of Metal Substitution on Iodine Evolution.

Many works reported the encapsulation of iodine in metal-organic frameworks as well as the I2 → I3- chemical conversion. This transformation has been examined by adsorbing gaseous iodine on a series of UiO-66 materials and the different Hf/Zr metal ratios (0-100% Hf) were evaluated during the evolution of I2 into I3-. The influence of the hafnium content on the UiO-66 structure was highlighted by PXRD, SEM images, and gas sorption tests. The UiO-66(Hf) presented smaller lattice parameter (a = 20.7232 Å), higher crystallite size (0.18 ≤ Φ ≤ 3.33 μm), and smaller SSABET (818 m2·g-1) when compared to its parent UiO-66(Zr) ─ a = 20.7696 Å, 100 ≤ Φ ≤ 250 nm, and SSABET = 1262 m2·g-1. The effect of replacing Zr atoms by Hf in the physical properties of the UiO-66 was deeply evaluated by a spectroscopic study using UV-vis, FTIR, and Raman characterizations. In this case, the Hf presence reduced the band gap of the UiO-66, from 4.07 eV in UiO-66(Zr) to 3.98 eV in UiO-66(Hf). Furthermore, the UiO-66(Hf) showed a blue shift for several FTIR and Raman bands, indicating a stiffening on the implied interatomic bonds when comparing to UiO-66(Zr) spectra. Hafnium was found to clearly favor the capture of iodine [285 g·mol-1, against 230 g·mol-1 for UiO-66(Zr)] and the kinetic evolution of I2 into I3- after 16 h of I2 filtration. Three iodine species were typically identified by Raman spectroscopy and chemometric analysis. These species are as follows: "free" I2 (206 cm-1), "perturbed" I2 (173 cm-1), and I3- (115 and 141 cm-1). It was also verified, by FTIR spectroscopy, that the oxo and hydroxyl groups of the inorganic [M6O4(OH)4] (M = Zr, Hf) cluster were perturbed after the adsorption of I2 into UiO-66(Hf), which was ascribed to the higher acid character of Hf. Finally, with that in mind and considering that the EPR results discard the possibility of a redox phenomenon involving the tetravalent cations (Hf4+ or Zr4+), a mechanism was proposed for the conversion of I2 into I3- in UiO-66─based on an electron donor-acceptor complex between the aromatic ring of the BDC linker and the I2 molecule.

Impact of coordination ability of the selected anions on tuning the structure of Hg(II) complexes constructed from a neutral dithione ligand: Iodine uptake and DFT theoretical studies

In view to examine the role of coordination potential of the selected anions on architect of complexes, HgL2](ClO4)2 (C1) and [HgL2](PF6)2 (C2) were synthesized with a HgS4 core structure by a flexible sulfur donor (1,1-bis(3-methyl-4-imidazoline-2-thione)methane ligand(L). The C1 was crystalized via a branched tube method in MeOH/H2O as a solvent. They have been characterized by the FT-IR, elemental analysis, X-ray powder diffraction (PXRD), density functional theory (DFT) calculations, and considered for the iodine adsorption experiments. Although MOFs and CPS were extensively being studied, but mono and binuclear complexes were rarely used as an adsorbent for removal of the iodine. Additionally, to probe the impact of anions on the structure of complexes, and iodine uptake properties, C1 and C2 were compared with the published dimeric ones [Hg2L2Cl4](C3) and [Hg2L2Br4](C4) with a HgX2S2 core structure. All complexes showed a good performance in removal of iodine from the pollutants. This was supported by a sharp decrease in the intensity of a band at 523 nm nominated to the π*g(p) (HOMO) → σ*u(p) (LUMO) transitions in the free I2 molecule. The iodine capture performance of the monomeric complexes is substantially different with the dimeric ones. C1and C2 remove more than 99% of iodine molecules in the solution within 2 h, whereas C3 and C4 need 24 h to achieve the equilibrium point. The DFT studies and band gap calculations confirmed a charge transfer transition from each of the complexes to the σ*u(p) (LUMO) of the adsorbed iodine molecules with a lower energy relative to the free I2 band gap. Nonlinear optical responses (NLO) and charge transfer properties of the C1-C4 complexes were inspected by the DFT calculations.

Cu(I)-organic framework as a platform for high-efficiency selective adsorption of methylene blue and reversible iodine uptake

A Cu(I)-MOF, namely {[Cu(4-PTZ)]·(H2O)0.5}n (1), that contains rhombic channels with the size of 10.174 ​Å ​× ​16.965 ​Å has been obtained based on in situ generated 5-(4-pyridyl)-1H-tetrazole ligand. Compound 1 not only displays remarkable capability for selective adsorption toward the organic dye Methylene Blue (149.5 ​mg ​g−1), but also shows reversible adsorption of I2 molecules in hexane medium (96.2%). Therefore, compound 1 should be a promising MOF-based bifunctional adsorbent in the field of pollutant removal.

Application of Morse potential and improved deformed exponential-type potential (IDEP) model to predict thermodynamics properties of diatomic molecules

The thermal properties of three diatomic molecules such as hydrogen (H2), carbon monoxide (CO) and iodine (I2) are theoretically predicted. To this end, two different potential models are considered, Morse potential and improved deformed exponential-type potential (IDEP). The Schrödinger equation is analytically solved to obtain energy levels. For the Morse and IDEP potential models, the Laplace transformation and the Greene–Aldrich approximation and appropriate coordinate transformation are employed, respectively. In the former potential model, we have obtained energy eigenvalues by considering position-dependent effective mass. Using the energy levels of two models, the partition function is first determined. Second, thermal functions of the molecules such as heat capacity, enthalpy and entropy are obtained and compared with the available results. The calculated enthalpy using the two models for CO and I2 molecules is in excellent agreement in comparison with the available data in a wide temperature range. But, the obtained enthalpy of H2 molecule using the Morse potential at high temperatures does not agree excellently with the experimental data. The entropy of H2, CO and I2 using the two models is tin good agreement in comparison with the available data in a wide temperature range whereas the entropy of H2 at low temperatures does not agree excellently with the experimental data. Our theoretical results using the two potential models do not show a suitable prediction about the heat capacity at a constant pressure of H2, CO and I2 molecules, But the IDEP shows more agreement compared to the Morse potential.

Promotion Effect by Organic Compounds on Dissolution of an Iodine Film Formed by Electrochemical Oxidation of Iodide Ions in an Aqueous Solution

When iodide ions (I−) are electrochemically oxidized in an aqueous solution containing a high concentration of I−, an iodine (I2) film is formed on the electrode surface and inhibits further oxidation of I−. The effect of adding an organic compound as an additive on the I2 film was investigated and discussed in the light of electrochemical investigations, spectroscopic analyses, and quantum chemical calculations. Aprotonic organic compounds such as acetonitrile (AN) increased the current of I− oxidation while protonic organic compounds such as ethanol (EtOH) did not increase it. The effect did not simply correspond to the increase in solubility of I2 molecules. In the theoretical calculations, AN showed a behavior that it promoted hydration of an I2 molecule by coordinating with the I2 molecule while EtOH formed hydrogen bonds with H2O molecules and did not show the behavior. AN desorbed from the I2 molecule when the coordinated I2 molecule was hydrated. The aprotonic organic compounds were considered to act as a catalyst to promote the hydration of the I2 molecules contained in the I2 film and thereby promote dissolution of the I2 film.

Solutions of Schrodinger equation and thermodynamic properties of Iodine and Scandium Fluoride molecules based on Formula method

The study presents the thermodynamic properties of the Iodine and Scandium Fluoride molecules with molecular Deng-Fan potential. The bound state energy solution of the radial Schrodinger equation is obtained via the formula method. The partition function and other thermodynamic properties are evaluated via the Poisson summation approach. The numerical values of energy of the I2 and ScF molecules are found to be in agreement with results obtained from other methods in the literature. The results further show that the partition function decreases, and then converges to a constant value as temperature increases.

The synthesis, structure, and spectral properties of antimony(III) phthalocyanine obtained under iodine vapor atmosphere: (SbIIIPc)(I3) ½(I2)

New antimony(III) phthalocyanine complex under iodine vapor atmosphere, (SbIIIPc)(I3).½(I2), (1), was obtained. The (SbIIIPc)(I3).½(I2) crystallizes in the centrosymmetric space group of the triclinic system. The (SbPc)+ unit is non-planar Two inversion related (SbIIIPc)(I3) units interact each other via neutral I2 molecule yielding {[C32H16N8Sb](I3)}2(I2) dimeric aggregate. Resonance Raman spectroscopy was used to identification of the iodine forms in crystal. The aggregates related by translation in the direction of the a-axis form a stacking structure. However, within the stacks, the Pc rings are clearly shifted, so the π-π interactions is relatively very low, due to their non-planarity, as well as by only partial overlapping of the outermost six-membered rings of the adjacent back-to-back-oriented (SbPc)+ macrocycles. The interaction between the building units (SbPc)+, I3− and I2 were analyzed using the Hirshfeld surface and the analysis of the 2D fingerprint plots. Relatively low interactions of π…π result in its considerable solubility, which manifests itself particularly in the improvement of optical properties of solutions. UV–Vis absorption spectra of 1 were taken in DMSO and toluene solutions in the concentration range from 10−5 to 10−6 mol/l. No significant changes related to aggregation in solutions were observed. Diffuse reflectance spectroscopy (DSR) due to interactions between the molecules in solid-state, showed much wider bands compared to the UV–Vis bands of the complex in solution. Oxidation of (SbIIIPc)(I3).½(I2) in methanol solution by H2O2 yields SbVPc derivative. Both SbIII and SbV phthalocyanine derivatives absorb near infrared light (600–900 nm) which should be intriguing with the point of view of potential use as an infrared cut filter for plasma display and silicon photodiodes, and in addition to as photosensitizers for semiconductor lasers.

Compacting the density matrix in quantum dynamics: Singular value decomposition of the surprisal and the dominant constraints for anharmonic systems.

We introduce a practical method for compacting the time evolution of the quantum state of a closed physical system. The density matrix is specified as a function of a few time-independent observables where their coefficients are time-dependent. The key mathematical step is the vectorization of the surprisal, the logarithm of the density matrix, at each time pointof interest. The time span used depends on the required spectral resolution. The entire course of the system evolution is represented as a matrix where each column is the vectorized surprisal at the given time point. Using the singular value decomposition (SVD) of this matrix, we generate realistic approximations for the time-independent observables and their respective time-dependent coefficients. This allows for a simplification of the algebraic procedure for determining the dominant constraints (the time-independent observables) in the sense of the maximal entropy approach. A non-stationary coherent initial state of a Morse oscillator is used to introduce the approach. We derive the analytical exact expression for the surprisal as a function of time, and this offers a benchmark for comparison with the accurate but approximate SVD results. We discuss two examples of a Morse potential of different anharmonicities, H2 and I2 molecules. We further demonstrate the approach for a two-coupled electronic state problem, the well-studied non-radiative decay of pyrazine from its bright state. Five constraints are found to be enough to capture the ultrafast electronic population exchange and to recover the dynamics of the wave packet in both electronic states.

Salts of 4-[(benzyl-amino)-carbon-yl]-1-methyl-pyridinium and iodide anions with different cation:iodine stoichiometric ratios.

The two iodide salts, 4-[(benzyl-amino)-carbon-yl]-1-methyl-pyridinium iodide-iodine (2/1), C14H15N2O+·I-·0.5I2, I, and 4-[(benzyl-amino)-carbon-yl]-1-methyl-pyridinium triiodide, C14H15N2O+·I3 -, II, with different cation:iodine atoms ratios were studied. Salt I contains one cation, one iodide anion and half of the neutral I2 mol-ecule in the asymmetric unit (cation:iodine atoms ratio is 1:2). Salt II contains two cations, one triiodide anion (I 3 -) and two half triiodide anions (cation:iodine atoms ratio is 1:3). The NH group forms N-H⋯I hydrogen bonds with the I- anion in the crystal of I or N-H⋯O hydrogen bonds in II where only triiodide anions are present.

A new theoretical study of the deformed unequal scalar and vector Hellmann plus modified Kratzer potentials within the deformed Klein–Gordon equation in RNCQM symmetries

In this paper, within the framework of relativistic quantum mechanics and using the improved approximation scheme to the centrifugal term for any [Formula: see text]states via Bopp’s shift method and standard perturbation theory, we have obtained the modified energy eigenvalues of a newly proposed modified unequal vector and scalar Hellmann plus modified Kratzer potentials (DUVSHMK-Ps) for some diatomic N2, I2, CO, NO, O2 and HCl molecules. This study includes corrections of the first-order in noncommutativity parameters [Formula: see text]. This potential is a superposition of the attractive Coulomb Yukawa potential plus the Kratzer potential and new central terms appear as a result of the effects of noncommutativity properties of space–space. The obtained energy eigenvalues appear as a function of noncommutativity parameters, the strength parameters [Formula: see text] and [Formula: see text] of the (scalar vector) Hellmann potential, the screening range parameter [Formula: see text], the dissociation energy of the vector, and scalar potential [Formula: see text], the equilibrium inter-nuclear distance [Formula: see text] in addition to the atomic quantum numbers [Formula: see text]. Furthermore, we obtained the corresponding modified energy of DUVSHMK-Ps in the symmetries of non-relativistic noncommutative quantum mechanics (NRNCQM). In both relativistic and non-relativistic problems, we show that the corrections on the spectrum energy are smaller than the main energy in the ordinary cases of RQM and NRQM.

Photofragmentation of I2 molecules inside helium clusters: model calculations using a quantum effective potential

We report the results of model calculations for the photodissociation of iodine molecules inside liquid helium clusters composed of several thousand atoms. The helium clusters are described by a quantum effective potential between helium atoms. Classical trajectories are run with this potential model in order to determine excitation energy thresholds for caging of atomic iodine fragments followed by recombination or, alternatively, production of photofragments which leave the helium cluster. Typical photofragments are iodine atoms carrying along a certain number of helium atoms. The computed photofragment velocity and size distributions for several cluster sizes compare favourably with experimental observations for related molecular systems.

Stepwise Observation of Iodine Diffusion in a Flexible Coordination Network Having Dual Interactive Sites.

We created dual interactive sites in a porous coordination network using a CuI cluster and a rotation-restricted ligand, tetra(3-pyridyl)phenylmethane (3-TPPM). The dual interactive sites of iodide and Cu ions can adsorb I2 via four-step processes including two chemisorption processes. Initially, one I2 molecule was physisorbed in a pore and successively chemisorbed on iodide sites of the pore surface, and then the next I2 molecule was physisorbed and chemisorbed on Cu ions to form a cross-linked network. We revealed the four-step I2 diffusion process by single-crystal X-ray structure determination and spectroscopic kinetic analysis.

Thermodynamic properties of several substances using Tietz–Hua potential

Thermodynamic properties of five diatomic molecules such as H2, HF, I2, N2 and O2 have been theoretically predicted. To this end, the interaction potential of the diatomic molecules has been considered as the Tietz–Hua (TH) potential model. Then, the Schrodinger equation was solved for the potential and energy eigenvalues were obtained in the closed form by using the Nikiforov–Uvanov (NU) method. Using the energy eigenvalues, we have determined partition function, mean energy, specific heat at constant pressure and volume, entropy and enthalpy of the diatomic molecules and compared with experimental data. Our results were in good agreement with experimental data. It is found that the Tietz–Hua potential model is a suitable case to predict thermodynamic functions of H2, HF, I2, N2 and O2 molecules at wide ranges of temperatures.