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A theoretical study of SmXO₃ ($\mathrm{\text{X}}=\mathrm{\text{Al}}$, Co) cubic perovskites for vibrational properties and Reststrahlen band is done within the framework of Density Functional Perturbation Theory (DFPT) implemented in Quantum ESPRESSO. The vibrational properties of the Samarium-based perovskites are figured using Martins–Troullier pseudo potentials. The phonon density of states and phonon dispersion curves in first Brillouin zone are computed and discussed in which two optical phonon frequencies, ${\omega }_{\mathrm{\text{TO}}}$ and ${\omega }_{\mathrm{\text{LO}}}$, are targeted to find Reststrahlen band for these materials. No imaginary frequency was noted, which shows the structural stability of both perovskites in cubic state. Reststrahlen bandgap and Lyddane–Sachs–Teller (LST) relation for these materials are calculated using optical phonon frequencies and applications are specified. Reststrahlen band of both materials is found to exist in the Far Infra-red region (ranging from 0.3 to 6.0 THz) showing that they can be identified by throwing light of Infrared region upon them in geological applications.

A comprehensive theoretical study has been carried out to examine the electronic and thermoelectric properties of As$XY$ (where $X=\mathrm{\text{S}}$, Se; $Y=\mathrm{\text{Cl}}$, Br, and I) monolayers. The lattice constants of these monolayers are optimized to determine their most stable configurations. The electronic and thermoelectric characteristics of these monolayers are calculated using state-of-the-art computational methods. Specifically, the first-principles calculations in combination with semiclassical Boltzmann transport theory were employed to gain insights into their behavior. One of the crucial findings of the study is the observation of an indirect band nature in all the studied monolayers. This characteristic provides valuable information about the materials’ electronic behavior and potential applications. Furthermore, the impacts of tensile and compressive strains on these monolayers are investigated. Interestingly, we observed changes in the band value when strain is applied, which opens up exciting possibilities for engineering their electronic properties. Importantly, despite these changes, the band nature of the monolayers remains consistent. In particular, it is found that the AsSI monolayer exhibits a remarkable enhancement in the Seebeck coefficient, both in the unstrained state and under a compressive strain of 4% in the p-type region. This enhancement leads to a higher power factor (PF), suggesting that AsSI monolayers could be promising candidates for efficient thermoelectric devices. Overall, these findings highlight the potential of strain engineering to tailor the electronic properties of As$XY$ monolayers, offering exciting opportunities for their application in thermoelectric devices. This research contributes valuable insights into the design and optimization of novel materials for future energy conversion and electronic applications.

Inductive effect in the aromatic moieties of [2,2]paracyclophane is theoretically analyzed with the density functional theory. The inclusion of different substituents in one of the moieties seems to affect the behaviour of the other. The nature of activating or deactivating groups as substituents reflect known facts on electrophilic aromatic substitutions derived from the inductive effects. The interesting feature in this case is that the phenomenon is transfered from the substituted deck to the other via transannular effects. The strain suffered by the cyclophane molecule is also analyzed.

The mechanistic study on the oxidation of 2-propanol by the model complex CpIr[κ²-(N,C)-(NHCMe₂–2-C₆H₄)] (R) is performed using density functional theory (DFT) calculations. It is found that the rate-determining step is the hydrogen migration from 2-propanol to R via a six-membered transition state. The reaction is calculated to be favorable thermodynamically. To further understand the reaction mechanism, some bonding features are discussed, such as the correlation of the geometry of R and the Ir–N π bond involved, the transformation of the nitrogen hybridization, the variation of Ir–N bond distance, and so on.

In this paper, we explore theoretically energetic and structural properties of the possible cations formed via hydride ion abstraction at various sites of sugar part of cytosine nucleosides by employing B3LYP exchange-correlation functional with 6-311++G (d,p) orbital basis sets. In general, the hydride ion abstracted sugar cations of cytosine nucleosides have the following stability sequence: caH2′ > caH1′ > caH3′ > caH4′ > caH5′ for cytidine and caH1′ > caH4′ > caH3′ > caH5′ > caH2′ for deoxycytidine. Furthermore, the effect of solvent environment on the stability order of cations integral equation formalism of the polarized model (IEF-PCM) was employed to model aqueous solution. The natural bond orbital method was used for quantitative analysis of the electron delocalization donor–acceptor interaction of various hydride ions abstracted centers of cytosine nucleosides. The role of CH⋯O and HO⋯H intramolecular hydrogen bonds in the stability of cations is investigated based on the results of topological properties of atom in molecule theory. Moreover, variations of significant structural parameters such as puckering amplitudes and phase angles of sugar parts of cytosine nucleosides after cation formation are also found.

Free-base phthalocyanine ligands and their zinc derivatives representing functionally monosubstituted (A₃B type) or tetrasubstituted (A₄ type) compounds with 2-diethoxyphosphoryl-4-methylpenta-1,3-dienyl moieties have been synthesized for the first time. Their structures were characterized by MALDI-TOF mass-spectrometry as well as ¹H and ³¹P NMR spectroscopy data. A tendency to aggregation in dependence on the nature of the solvent was demonstrated as well.

The role of the base nature during complexation of 2-hydroxy-9(10),16(17),23(24)-tri-tert-butyl-29H,31H-phthalocyanine ligand (1) with zinc acetate was studied by the UV-vis spectroscopy and DFT calculations. The latter allowed us to explain the selective formation of double-coordinated J-type dimer in the presence of lithium methoxide. Spectropotentiometry was used to study the nucleophilic properties of the dimeric complex in comparison with the corresponding monomer and has demonstrated the strong intramolecular interactions of macrocycles.

The influence of the chalcogen atom (X) on the molecular and electronic structures for the series of Mg${}^{\mathrm{\text{II}}}$ tetra(1,2,5-chalcogenadiazolo)porphyrazines [TXDPzMg] (X $=$ O, S, Se, Te) and their monoaqua complexes [TXDPzMg(OH${}_{\mathrm{\text{2}}})$] was studied using DFT methods (B3LYP and PBE0 functionals) with cc-pVTZ basis sets. The chalcogen atom X changes strongly the geometry of the fused 1,2,5-chalcogenadiazole rings, but has only a weak influence on the dimensions of the coordination cavity of the porphyrazine macrocycle in [TXDPzMg] leading to its slight expansion in the sequence S < Se < Te < O. The electron density distribution was considered in terms of the natural bond order (NBO) and the natural population analysis (NPA). The frontier molecular orbitals are destabilzed along with the decrease of electronegativity of the chalcogen atoms. The a${}_{\mathrm{\text{1u}}}$ and e${}_{\mathrm{\text{g}}}^{\ast }$ orbitals (HOMO and LUMO) are mainly localized on atoms constituting the internal 16-membered macrocycle, while the chalcogen atoms have the strongest effect on the composition of the filled $\pi$-MOs having the a${}_{\mathrm{\text{2u}}}$ symmetry – 2a${}_{\mathrm{\text{2u}}}$ and lower lying 1a${}_{\mathrm{\text{2u}}}$ orbitals. The Gouterman type a${}_{\mathrm{\text{2u}}}$ orbital with predominant localization on the nitrogen atoms of the internal 16-membered macrocycle is 2a${}_{\mathrm{\text{2u}}}$ for the O- and S-containing complexes and for the Se- and Te-analogs it becomes 1a${}_{\mathrm{\text{2u}}}$, while the higher lying 2a${}_{\mathrm{\text{2u}}}$ orbital resides mainly on the fused heterocycles (Se/Te and C${}_{\beta }$ atoms). The lowest excited states have been calculated for [TXDPzMg] and used for the explanation of the peculiarities and tendencies observed in the experimental electronic absorption spectra available for the S, Se- and Te-containing Mg${}^{\mathrm{\text{II}}}$ complexes.