The noncovalent chalcogen interaction between SO2/SO3 and diazines was studied through a dispersion-corrected DFT Kohn–Sham molecular orbital together with quantitative energy decomposition analyses. ...For this, supramolecular circular chains of up to 12 molecules were built with the aim of checking the capability of diazine molecules to detect SO2/SO3 compounds within the atmosphere. Trends in the interaction energies with the increasing number of molecules are mainly determined by the Pauli steric repulsion involved in these σ-hole/π-hole interactions. But more importantly, despite the assumed electrostatic nature of the involved interactions, the covalent component also plays a determinant role in its strength in the involved chalcogen bonds. Noticeably, π-hole interactions are supported by the charge transfer from diazines to SO2/SO3 molecules. Interaction energies in these supramolecular complexes are not only determined by the S···N bond lengths but attractive electrostatic and orbital interactions also determine the trends. These results should allow us to establish the fundamental characteristics of chalcogen bonding based on its strength and nature, which is of relevance for the capture of sulfur oxides.
The
N
-alkylation reaction of pyrazole derivatives with halomethanes was studied using density functional theory (DFT). The hybrid method B3LYP was employed, along with an ECP basis set such as ...LANL2DZ for halogen atoms (X = Cl, Br, I) and the 6–311 + G(d,p) basis set for all other atoms. In order to predict the specific site at which the pyrazole derivatives interact with halomethanes, local reactivity descriptors such as the Fukui functions were calculated. Detailed analysis of transition-state energies showed that alkylation occurred at the nitrogen atom N
2
in the pyrazole derivatives, in agreement with the chemical reactivity results. The reaction mechanisms were elucidated by performing intrinsic reaction coordinate (IRC) calculations that considered the effects of the solvent and the species of halogen in the halomethane.
Recently, halogen bonding (XB) has received increased attention as a new type of non‐covalent interaction widely present in nature. In this work, quantum chemical calculations at DFT level have been ...carried out to investigate halogen bonding interactions between COn(n = 1 or 2) and dihalogen molecules XY (X = F, Cl, Br, I and Y = Cl, Br, I). Highly accurate all‐electron data, estimated by CCSD(T) calculations, were used to benchmark the different levels of computational methods with the objective of finding the best accuracy/computational cost. Molecular electrostatic potential, interaction energy values, charge transfer, UV spectra, and natural bond orbital (NBO) analysis were determined to better understand the nature of the XB interaction. Density of states (DOS) and projected DOS were also computed. Hence, according to these results, the magnitude of the halogen bonding is affected by the halogen polarizability and electronegativity, where for the more polarizable and less electronegative halogen atoms, the σ‐hole is bigger. Furthermore, for the halogen‐bonded complexes involving CO and XY, the OC∙∙∙XY interaction is stronger than the CO∙∙∙XY interaction. Thus, the results presented here can establish fundamental characteristics of halogen bonding in media, which would be very helpful for applying this noncovalent interaction for the sustainable capture of carbon oxides.
Quantum chemical calculations at DFT level have been carried out to investigate halogen bonding interactions between COn(n = 1 or 2) and dihalogen molecules XY (X = F, Cl, Br, I and Y = Cl, Br, I). Molecular electrostatic potential, interaction energy values, charge transfer, UV spectra, and NBO analysis, density of states (DOS) and projected DOS allow us to better understanding the nature of the Intermolecular Interactions in the formed complexes.
Hybrid organic-inorganic perovskite solar cells (PSCs) currently receives extensive amounts of focus as one of e main study areas in photovoltaic technology, despite its significant progress and high ...efficiency; the PSCs face numerous issues, such as stability over time and toxic effects of lead. Recently, to address the problem of toxicity, FASnI3 is commonly used to be an absorber in perovskite solar device due to its promising performance. During this article, we formed and modeled a lead-free n-i-p perovskite solar device made of FASnI3 on i-layer and FAGeCl3 for a p-layer, FASnI3 in the n-layer using the simulator SCAPS-1D. to gain better understanding of this solar cell, various parameters impacting the device performance including thickness and doping level of i-layer, n-layer and p-layer thickness, the total i-layer density of defect and the impact of the temperature on the efficiency of device, are investigated and discussed. this new study is interesting since we added a thin layer of FASnI3 that was strongly n-doped to achieve great performance. The importance and effect of n+-FASnI3 on the device performance were showed and discussed. The efficiency of the device has been demonstrated to be affected by both the thickness and doping level of the extra layer n+-FASnI3. the Voc of the concerned device was increased to 1.1V after adding n+-FASnI3 layer, the current density Jsc increased to 31.42mA/cm2, the Fill Factor up to 87.33%, after including n+-FASnI3 into the PSC, a high efficiency of 30.19% can be obtained. These simulation results will allow it achievable to develop and manufacture, high-efficiency, with no-lead PSCs.
Using density functional theory (DFT), we treat the reaction of coupling of CO2 with aziridine in gas phase, in the presence of water and of a green catalyst (NaBr). Computations show that, in gas ...phase, this ring‐opening conversions to oxazolidinones initiates by coordinating a CO2 molecule to the nitrogen atom of the aziridine. Then, a nucleophilic interaction between one oxygen atom of the coordinated CO2 and the carbon atom of the aziridine occurs. For methyl substituted aziridine, two pathways are proposed leading either to 4‐oxazolidinone or to 5‐oxazolidinone. Besides, we show that the activation energy of this reaction reduces in aqueous solution, in the presence of a water molecule explicitly or NaBr catalyst. In addition, the corresponding reaction mechanisms and regioselectivity associated with this ring‐opening conversions to oxazolidinones, in the presence of carbon dioxide are found to be influenced by solvent and catalyst. The present findings should allow better designing regioisomer oxazolidinones relevant for organic chemistry, medicinal and pharmacological applications.
Context
Heavy metals are highly noxious, and their presence can cause diverse effects on living organisms and the environment. Crown ether porphyrins and phthalocyanines are known to effectively ...extract these pollutants and are also used in photovoltaic devices. This study aims to evaluate various factors that govern intramolecular charge transfer (ICT) and photo-injection processes, including maximum absorption wavelength (
λ
max
), density of states (DOS), charge transfer dipole (
μ
CT
), light harvesting efficiency (LHE), open-circuit voltage (
V
oc
), and free energy change of electron injection (Δ
G
inj
) in order to investigate the performance of different compounds designed from metalloporphyrins for bulk-heterojunction organic solar cell (BHJ-OSC) applications. The porphyrin complex showed the best optoelectronic properties, with remarkable LHE values and CT amounts compared to phthalocyanine derivatives. The central metal played a significant role in optimizing the optical properties of the materials for use in solar cells. HgPr4O and CdPr4O were found to have optimal
V
oc
values, resulting in effective injection, high electron, and hole mobilities, making them ideal materials for highly efficient BHJ-OSC devices.
Methods
Density functional theory (DFT) approach was employed with the B3LYP functional and the def2TZVP basis set as implemented in the Gaussian 16 revision C.01 program to investigate the designed complexes and to compute geometrical parameters, frontier molecular orbitals (FMOs), and natural bond orbital (NBO). Furthermore, the time-dependent density functional theory (TD-DFT) method was used to analyze the optical properties and photovoltaic characteristics of selected metalloporphyrins by examining the UV-Vis spectra. In summary, the study presents a thorough description of the structural and electronic properties of the investigated complexes and provides insights into their potential use in photovoltaic applications.
A new organic-inorganic hybrid compound, (C
12
H
22
N
2
)CuCl
4
, has been synthesized by slow evaporation at room temperature and characterized using elemental analysis, powder X-ray diffraction, ...FT-IR, UV-Vis and mass spectroscopy. Single-crystal X-ray diffraction analysis indicates that the asymmetric unit in this compound consists of one tetrahedral CuCl
4
2-
ion and one diprotonated organic cation (C
12
H
22
N
2
)
2+
, all of which lie in general positions. The crystal structure of the title salt is made up of mixed layers, formed by organic cations and inorganic anions, stacking along the b-axis. Crystal cohesion is achieved through N-H...Cl hydrogen bonds between organic cations and inorganic anions, and Cl...Cl interactions, building up a two-dimensional architecture. Thermal behavior (DTA/TGA) of this copper complex was also explored showing the different steps of weight loss. Hirshfeld surface analysis has been performed to investigate the intermolecular interactions and crystal packing of the title compound. Optical properties were recorded at room temperature using UV-visible spectroscopy in the spectral range 200-700 nm. The optical absorbance was measured to determine the optical band gap using Kubelka-Munk function. The electronic transition of the title complex was recorded in ethanol solvent and the electronic distribution of HOMO − LUMO was rationalized theoretically through density functional theory (DFT).
Metallo-dithiaporphyrin small molecules have been designed by substituting Ru(ii) with various transition metals at the same oxidation state (M = Mn, Fe, Ni, Cu) as donor materials for Bulk ...Heterojunction Organic Solar Cells (BHJ-OSCs). Density functional theory (DFT) and time-dependent DFT (TD-DFT) have been used to study the optoelectronic properties of metallo-dithiaporphyrin at various functionals and basis sets. We discovered that the open-circuit voltage (VOC) value increases when Ru(ii) in Ru(S2TTP)Cl2 (S2TTP = tetra-p-tolyldithiaporphyrin) is substituted. In addition, the light harvesting efficiency (LHE) of nickel, manganese, and iron complexes was found to be similar to that of ruthenium, and the iron complex furthermore presented a comparable charge transfer in the excited state corresponding to the Q-band, compared to Ru(S2TTP)Cl2. Hence M(S2TTP)Cl2 (M = Mn, Fe, Ni) appear to be potential low cost candidate donor molecules within a bulk heterojunction solar cell. We further propose suitable engineered acceptor pigments, fitted to provide a good overall solar cell efficiency.
Chalcogen bonding is a noncovalent interaction, highly similar to halogen and hydrogen bonding, occurring between a chalcogen atom and a nucleophilic region. Two density functional theory (DFT) ...approaches B3LY‐D3 and B97‐D3 were performed on a series of complexes formed between CX2 (X = S, Se, Te) and diazine (pyridazine, pyrimidine and pyrazine). Chalcogen atoms prefer interacting with the lone pair of a nitrogen atom rather than with the π‐cloud of an aromatic ring. CTe2 and CSe2 form a stronger chalcogen bond than CS2. The electrostatic potential of CX2 (X = S, Se and Te) reveals the presence of two equivalent σ‐holes, one on each chalcogen atom. These CX2 molecules interact with diazine giving rise to supramolecular interactions. Wiberg bond index and second‐order perturbation theory analysis in NBO were performed to better understand the nature of the chalcogen bond interaction.
Formation of supramolecular assemblies by charge transfer interactions between an aromatic heterocyclic such as Lewis base compounds containing nitrogen atom and an electrophilic region of a chalcogen (S, Se and Te). These interactions can play a dominant role in the fields of supramolecular architecture, molecular recognition, materials science and crystal engineering.
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