HCl Molecules Research Articles

Reparametrised Pöschl–Teller oscillator and analytical molar entropy equation for diatomic molecules

In this study, the reparametrised Pöschl–Teller (RPT) oscillator is constructed for applications to diatomic molecules. Equations for bound state eigen energies and molar entropy are derived for the oscillator. With the aid of the proposed model, seven diatomic molecules are analysed including 7Li2 (a 3Σu +), Na2 (c 1Πu), HCl (X 1Σ+), MgO (X 1Σ+), SO (X 3Σ-), SiO (X 2Σ+), and TiO (X 2Σ+). The average absolute deviation (AAD) and mean absolute percentage deviation (MAPD) are employed as the goodness of fit indicators. Computed AAD and MAPD reveal that the RPT oscillator is an excellent model for the diatomic molecules, the potential is approximately equivalent to the improved Tietz and improved Scarf potentials in the literature. An MAPD of 0.3609% from observed data of gaseous HCl molecule is obtained using the equation of molar entropy proposed in this work. This is an indication that the RPT oscillator is a good model for representing the internal vibration of the HCl molecule.

Achieving highly exposed active sites of molybdenum carbide with the assistance of NH4Cl for efficient hydrogen evolution

Molybdenum carbide (Mo2C) shows tremendous potentials in electrocatalytic hydrogen evolution reaction (HER). Nonetheless, the rational design of Mo2C and establishment of structure-performance correlation are still challenging. Herein, a facile NH4Cl-assisted approach has been realized to fabricate Mo2C by employing ammonium heptamolybdate and melamine as molybdenum and carbon sources, respectively. By virtue of the intercalation into the interlayers of intermediate graphitic carbon nitride, HCl molecules released from NH4Cl play a pivotal role in purifying the superfluous carbon matrix, which is a common byproduct during the preparation process of carbide. Furthermore, the participation of NH4Cl can sharply decrease in carbon content and significantly enhance the exposure of active carbide sites, which is proved to be the most essential factor affecting the catalytic activity of materials. As a result, the as-prepared catalyst presents remarkable HER performance in alkaline media, with a low overpotential of 126 mV at 10 mA cm−2 as well as small Tafel slope of 60.97 mV dec−1. Impressively, it even surpasses commercial Pt/C in the pragmatically meaningful high-current region (>80 mA cm−2), demonstrating its great potential to substitute the noble metal catalysts in practical alkaline HER process.

Metal-free transfer hydrochlorination of internal C-C triple bonds with a bicyclo[3.1.0]hexane-based surrogate releasing two molecules of hydrogen chloride.

The development and application of a transfer hydrochlorination reagent based on a trichlorinated bicyclo[3.1.0]hexane core that transfers two molecules of HCl per molecule of surrogate to a π-basic substrate under B(C6F5)3 catalysis is reported. Lewis acid-assisted chloride abstraction followed by thermal electrocyclic cyclopropyl-to-allyl cation ring opening releases ring strain as a previously unexploited driving force.

Empirical quality criteria for the approximation of the electronic term of a diatomic molecule by the Morse formula

A brief review of the latest results of the application of the approximation of the potential of a diatomic molecule by the Morse model function in applied spectroscopy is presented. The functions of the electronic terms of the diatomic molecules BeH, F2, H2, HCl, and Be2 are compared with their two alternative approximations by the Morse function. As a criterion, we used the differences between the original (approximated) term and its Morse models, which, combined with the dependence of the anharmonicity of the original terms on the vibrational quantum number ωexe(v), allowed to formulate some generalizations about the deformation of the form the original term in the approximations. Simulation always leads to an increase in the bond energy in the range of 7-50% and to an increase in the number of vibrational levels. In favorable cases, the contour shape is reproduced with a deviation of no more than 100-200 cm-1 in the lower part of the potential well. Key words: Morse formula, diatomic molecule, anharmonicity, electronic terms, vibrational structure.

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.

Transient Valence Charge Localization in Strong-Field Dissociative Ionization of HCl Molecules.

Probing transient charge localization in the innershell orbital of atoms and molecules has been made possible by the recent progress of advanced light sources. Here, we demonstrate that the ultrafast electron tunneling ionization by an intense femtosecond laser pulse could induce an asymmetric transient charge localization in the valence shell of the HCl molecule during the dissociative ionization process. The transient charge localization is encoded in the laser impulse acquired by the outgoing ionic fragments, and the asymmetry is revealed by carefully examining the electron tunneling-site distinguished momentum angular distribution of the ejected H^{+} fragments. Our work proposes a way to visualize the transient valence charge motion and will stimulate further investigations of the tunneling-site-sensitive ultrafast dynamics of molecules in strong laser fields.

Multiorbital impact on strong-field ionization of HCl molecules

We have put forward the time-dependent Hartree-Fock approach to investigate ionization dynamics of HCl molecules subjected to strong few-cycle laser pulses, which is based on the finite-element discrete-variable representation in prolate spheroidal coordinates and the Crank-Nicolson method. It is demonstrated that the electron is favored to be freed by the peak electric field pointing towards the H atom for the HCl molecule possessing the bonding length $R=2.5$ a.u., while the ionization prefers to occur for the maximum electric field pointing from the H nucleus to Cl nucleus with increasing internuclear separations. Analysis indicates that the ionization yield of $5\ensuremath{\sigma}$ electrons becomes significant with respect to that of $2\ensuremath{\pi}$ electrons with stretching bonding lengths, and the relative contributions of the ionization from $5\ensuremath{\sigma}$ and $2\ensuremath{\pi}$ electrons change as a function of internuclear separations, which gives rise to the above distinct oriented ionization of HCl molecules.

Infrared spectroscopy of the protonated HCl dimer and trimer.

The protonated HCl dimer and trimer complexes were prepared by pulsed discharges in supersonic expansions of helium or argon doped with HCl and hydrogen. The ions were mass selected in a reflectron time-of-flight spectrometer and investigated with photodissociation spectroscopy in the IR and near-IR regions. Anharmonic vibrational frequencies were computed with VPT2 at the MP2/cc-pVTZ level of theory. The Cl-H stretching fundamentals and overtones were measured in addition to stretch-torsion combinations. VPT2 theory at this level confirms the proton-bound structure of the dimer complex and provides a reasonably good description of the anharmonic vibrations in this system. The trimer has a HCl-HClH+-ClH structure in which a central chloronium ion is solvated by two HCl molecules via hydrogen bonding. VPT2 reproduces anharmonic frequencies for this system, including several combinations involving core ion Cl-H stretches, but fails to describe the relative band intensities.

Effect of the deformation parameter on the nonrelativistic energy spectra of the q-deformed Hulthen-quadratic exponential-type potential

In this study, an approximate solution of the Schr�dinger equation for the q-deformed Hulthen-quadratic exponential-type potential model within the framework of the Nikiforov�Uvarov method was obtained. The bound state energy equation and the corresponding eigenfunction was obtained. The energy spectrum is applied to study H2, HCl, CO and LiH diatomic molecules. The effect of the deformation parameters and other potential parameters on the energy spectra of the system were graphically and numerically analyzed in detail. Special cases were considered when the potential parameters were altered, resulting in deformed Hulthen potential, Hulthen potential, deformed quadratic exponential-type potential and quadratic exponential-type potential. The energy eigenvalues expressions agreed with what obtained in literature. Finally, the results can find many applications in quantum chemistry, atomic and molecular physics.

Smart Metal–Organic Frameworks with Reversible Luminescence/Magnetic Switch Behavior for HCl Vapor Detection

AbstractSmart luminescent metal–organic frameworks (MOFs) demonstrate promising performance in the detection of toxic gases. The incorporation of twisted or rotary organic ligands with aggregation‐induced emission (AIE) characteristics can provide further opportunities in designing such smart MOFs with new topologies and stimuli‐responsive behaviors. Herein, novel AIE MOFs are reported with reversible luminescence or a magnetic switch for HCl vapor detection. The twisted conformation of tetrakis(4‐carboxyphenyl)ethylene (TCPE) ligand leads to the unique [M+–L–M−–L–M]∞ (M = metal clusters, L = ligand) configuration for ZnMOF and CoMOF. Different from conventional MOFs with [M–L]∞ topology, ZnMOF and CoMOF exhibit a blue‐to‐yellow greenish fluorescence transition and a ferrimagnetic‐to‐antiferromagnetic switch behavior, respectively, upon recognition of HCl vapor. The adsorbed HCl molecules rather than coordinated ones are determined to be the main reason, and such luminescence and magnetic switch can be induced in a reversible manner via HCl vapor adsorption/desorption processes with high reliability. This work of AIE MOFs with twisted and rotary ligands shall pave new avenue in design of smart MOFs with new topologies and stimuli‐responsive behavior for real‐time sensing and detection applications.

Unraveling surface functionalization of Cr2B2T2 (T = OH, O, Cl, H) MBene by first-principles calculations

Synthesis of two-dimensional (2D) materials by wet-chemical methods is usually accompanied by surface functionalization, which plays critical roles in stabilizing and functionalizing the targeted materials. These termination reactions can bring thermodynamically stable products and versatile applications, however, leaving experimental characterization of surface structures challenging as well. In this work, newly emerging 2D conductive transition metal borides, Cr2B2 MBene is selected as a prototype to investigate the surface functionalization phenomenon. By first-principles calculation plus efficient structural exploration, we provide an atomistic understanding of the chemical origin and kinetics of surface functionalization occurred in aqueous environment, and screen the surface structure of Cr2B2T2 (T = OH, O, Cl, and H) MBenes. Results clearly unravel the functionalization process of MBenes and the stable surface structures of functionalized MBenes. It is found that both H2O and HCl molecules can split on the bare Cr2B2 in a nearly spontaneous manner, enabling functionalization of Cr2B2T2. Binding energy of termination groups on Cr2B2 quantifies the relative stability of functionalized Cr2B2T2 in the order: Cr2B2O2 > Cr2B2Cl2 > Cr2B2(OH)2 > Cr2B2H2. Furthermore, we demonstrate that both Cr2B2 and functionalized Cr2B2T2 MBenes are electronically conductive 2D materials with zero band gap, which is beneficial for electrochemical applications.

Superstatistics of Diatomic Molecules with the Shifted Deng-Fan Potential Model

In this article, we discuss the thermodynamic properties of the shifted Deng-Fan potential for HCl, CrH, CuLi, and ScF diatomic molecules using the q-deformed superstatistics approach. The partition function is obtained with the help of the generalized Boltzmann factor from the modified Dirac delta distribution. In addition, thermodynamic functions such as entropy, specific heat capacity, free energy, and mean energy are obtained using the partition function. Our results are presented graphically, and the ordinary statistical quantities are recovered when the deformation parameter tends to zero. Our results may be useful in the study of thermal fluctuations in atomic and molecular systems involving short-range interactions.

Adsorption behaviors of NH3 and HCl molecules on Fe-based crystal planes: A DFT study

By adopting the First-principles method based on the density functional theory (DFT), the adsorption properties of NH3 and HCl molecules intermingled in crude oil on the Fe-based crystal planes exposed on the inner surface of a duct in a crude distillation column have been conducted. Specifically, the calculated adsorption energy of NH3 and HCl reveal the most stable adsorption sites on the three planes, and the free energy at different temperatures was corrected. Furthermore, the charge density difference and the Bader charge obviously illustrate the direction of charge transfer and the valence of the atoms after adsorption. The results of projected electron density of states (PDOS), electron localization function (ELF) and the crystal orbital Hamilton population (COHP) reveal the nature of chemical bonds and the influence of specific atomic orbitals. Accordingly, the adsorption type of the two molecules on the Fe-based crystal planes is chemical adsorption. Considering the nature of the chemical bond and the multi-component environment of the distillation column, we infer that the possible causes of corrosion are coordination ions, hydrogen embrittlement and Cl− concentration.

Optical Properties of Doxorubicin Hydrochloride Load and Release on Silica Nanoparticle Platform.

Silica nanoparticles (SiO2 NPs) synthesized by the Stober method were used as drug delivery vehicles. Doxorubicin hydrochloride (DOX·HCl) is a chemo-drug absorbed onto the SiO2 NPs surfaces. The DOX·HCl loading onto and release from the SiO2 NPs was monitored via UV-VIS and fluorescence spectra. Alternatively, the zeta potential was also used to monitor and evaluate the DOX·HCl loading process. The results showed that nearly 98% of DOX·HCl was effectively loaded onto the SiO2 NPs’ surfaces by electrostatic interaction. The pH-dependence of the process wherein DOX·HCl release out of DOX·HCl-SiO2 NPs was investigated as well. For comparison, both the free DOX·HCl molecules and DOX·HCl-SiO2 NPs were used as the labels for cultured cancer cells. Confocal laser scanning microscopy images showed that the DOX·HCl-SiO2 NPs were better delivered to cancer cells which are more acidic than healthy cells. We propose that engineered DOX·HCl-SiO2 systems are good candidates for drug delivery and clinical applications.

Morse potential in relativistic contexts from generalized momentum operator: Schottky anomalies, Pekeris approximation and mapping

In this work, we explore a generalization of the Dirac and Klein–Gordon (KG) oscillators, provided with a deformed linear momentum inspired in nonextensive statistics, that gives place to the Morse potential in relativistic contexts by first principles. In the (1 + 1)-dimensional case, the relativistic oscillators are mapped into the quantum Morse potential. Using the Pekeris approximation, in the (3 + 1)-dimensional case, we study the thermodynamics of the S-waves states (l = 0) of the H2, LiH, HCl and CO molecules (in the non-relativistic limit) and of a relativistic electron, where Schottky anomalies (due to the finiteness of the Morse spectrum) and spin contributions to the heat capacity are reported. By revisiting a generalized Pekeris approximation, we provide a mapping from (3 + 1)-dimensional Dirac and KG equations with a spherical potential to an associated one-dimensional Schrödinger-like equation, and we obtain the family of potentials for which this mapping corresponds to a Schrödinger equation with non-minimal coupling.

Detection of HCl molecules by resonantly enhanced third-harmonic generation, driven by midinfrared laser pulses

We studied resonantly enhanced third-harmonic generation, induced by midinfrared, spectrally narrow-band, nanosecond laser pulses tuned in the vicinity of rovibrational molecular resonances. As we drive the frequency conversion process simultaneously close to single-, two-, and three-photon resonances, we get strong resonance enhancements of the third-harmonic yield by several orders of magnitude. The experimental setup requires only a single midinfrared laser beamline; the signal wavelength is easily separable from the much longer driving laser wavelength. We performed extended, systematic studies on the third-harmonic yield, spectral line shape and linewidth with laser intensity, frequency, and pressure. We determined a detection limit of ${10}^{15}$ $\mathrm{molecules}/{\mathrm{cm}}^{3}$, which indicates the potential of the approach for realistic applications in trace gas detection.

Analytical solutions of D-dimensional Klein–Gordon equation with modified Mobius squared potential

Approximate solutions of Klein–Gordon equation are obtained for the modified Mobius squared potential using the Nikiforov-Uvarov (NU) method. The relativistic energy eigenvalues and corresponding wave functions are obtained. It is further shown that in the non-relativistic limit, the energy eigenvalues reduces to that of Schrodinger equation. The behavior of CO, NO and HCl molecules are investigated subject to the modified Mobius squared potential. Numerical values of the energies of these diatomic molecules are also presented for arbitrary values of quantum numbers n and l. Finally, plots showing the variation of the energy against various potential parameters are presented for the selected diatomic molecules.

Complexity of HCl and H2 molecules under q-deformed Morse potential

The statistical complexity and its constituent information measures of Shannon information entropy and disequilibrium for HCl and H $$_2$$ molecules under q-deformed Morse potential are reported in the position and momentum space. A strong dependence of the statistical complexity on the potential deformation parameter q is established.

Nonadiabatic phenomena in molecular vibrational polaritons.

Nonadiabatic phenomena are investigated in the rovibrational motion of molecules confined in an infrared cavity. Conical intersections (CIs) between vibrational polaritons, similar to CIs between electronic polaritonic surfaces, are found. The spectral, topological, and dynamic properties of the vibrational polaritons show clear fingerprints of nonadiabatic couplings between molecular vibration, rotation, and the cavity photonic mode. Furthermore, it is found that for the investigated system, composed of two rovibrating HCl molecules and the cavity mode, breaking the molecular permutational symmetry, by changing 35Cl to 37Cl in one of the HCl molecules, the polaritonic surfaces, nonadiabatic couplings, and related spectral, topological, and dynamic properties can deviate substantially. This implies that the natural occurrence of different molecular isotopologues needs to be considered when modeling realistic polaritonic systems.

Свободное вращение простых молекул и характеристические температуры в стеклообразных полимерах

Purely rotational spectra of CO and HCl molecules added as a probe to polypropylene (PP) and polyvinyl chloride (PVC) were obtained and analyzed. It is shown that the shape of the bands of these spectra, which reflects the degree of disturbance of the rotational motion, is strongly influenced by the local dynamics of the polymer matrix. From the change in the integrated intensity of absorption with the temperature were found temperatures of the transition from free rotation of CO and HCl molecules to their libration, as well as the temperatures of the onset of defrosting of the conformational mobility of the chains of PP and PVC macromolecules.