Polycyclic Aromatic Compounds最新文献

The density functional theory (DFT) approach has become one of the most gainful means to scrutinize the molecular structure and vibrational spectra are finding well-known use in the applications related to biological systems. The experimental and theoretical on the molecular structure, electronic, and characteristics of 3, 4, 5-Trimethoxybenzaldehyde (TMB) are reported. The structure of the molecule was optimized and structural characteristics were determined by DFT using the wb97xd method with 6-311 G++ (d, p) basis sets. The vibrational assignments were made on the basis of potential energy distribution. A good consistency between the observed and calculated spectra was achieved. The intramolecular charge transfer and second-order perturbation theory of Fock Matrix in Natural bond orbital analysis by means NBO analysis. It shows the electronic stability of the compound arising from hyper conjugative interactions and charge delocalization of that molecule. Besides, the HOMO-LUMO, MEP, and Fukui were performed. In this review, the present benzaldehyde derivatives for skirmishing against bacteria strain Escherichia coli and fungi strain Candida Sp. Spectral and quantum chemical calculations are also discussed.

The use of chemical graph theory has been increased in almost every field of science in the last two decades. The graph invariants called topological descriptor are the numbers used to understand the physical and chemical properties of compounds. The use of narcotics causes many health and social issues in society. Narcotic drug addiction results in decreased pain perception, euphoria, dizziness, physical dependence, decreased breathing, and sleepiness in people. The overuse of narcotics may cause death. For the care and treatment of drug addictions, special health institutes provide proper medicines. The structures of narcotic drugs are explored with the help of degree-based graph invariants. In this article, we used degree-based topological indices to estimate the properties of narcotic drugs. Moreover, we have obtained that the topological indices utilize the antinarcotics drugs have a very strong correlation with the physicochemical properties mentioned in this manuscript.

In order to study the effect of substituents on the terpyridine molecular system, a series of substituted 2,2:6′,2″-terpyridines have been synthesized and fully characterized. The substitutions range from EWGs like –F to EDGs like –OMe, -NMe₂, triphenylamine (TPA), heterocycles like furan and fused rings like anthracene. The –F, -OMe, and -NMe₂ are connected to the terpyridine core via phenyl ring as spacer group whereas the TPA is attached via thienyl moiety. The furan and anthracene are directly appended to the terpyridine core. The synthesized terpyridines were structurally characterized with NMR and mass spectrometry. The terpyridines were then subjected to UV–Vis absorption, luminescence, and potentiometric analysis. An extension of the light harvesting window was observed for terpyridines with electron-donating groups (EDGs) as substituent. Density functional theory (DFT) based methods (B3LYP model with 6–311 G basis sets) were applied to optimize the molecular structures. The experimental absorption studies were simulated with TD-DFT based theoretical calculations (B3LYP with 6–311 G (d,p) basis set in DCM solvent using IEFPCM model) to ascertain the underlying electronic transitions. The findings were then used to define the structure-activity relationship.

Coumarin and its derivatives are extensively used as scaffolds in the synthesis of novel heterocyclic motifs. In the literature, several approaches especially involving metal and metal-free catalysts have been developed to get novel biological potential coumarin analogs. This review spotlights recent advancements in the synthesis of heterocyclic coumarin and its associated molecules recounting the literature articles from 2015 to the middle of 2022. Further, in this review, we have focused on the contents based on classical and non-classical methods for coumarin synthesis.

A variety of graphical invariants have been described and tested, offering lots of applications in the fields of nanochemistry, computational networks, and different scientific research areas. One commonly studied group of invariants is the topological index, which allows research on the chemical, biological, and physical properties of a chemical structure. Topological indices are numerical quantities that can be used to describe the properties of the molecular graph. In this article, we draw from the analytically closed formulas of molecular structures of polycyclic aromatic hydrocarbons by calculating temperature-based topological indices. Our results in this paper may be useful to better understand many physical and chemical properties of polycyclic aromatic hydrocarbons.

A magnetic nanocomposite based on graphene oxide was prepared. Fe₃O₄ nanoparticles were loaded on graphene oxide sheets and GO-Fe₃O₄ was covered by aniline-pyrrol copolymer to afford poly(Ani-co-Py)@GO-Fe₃O₄ nanocomposite. The poly(Ani-co-Py)@GO-Fe₃O₄ nanocomposite was characterized by FT-IR, TEM, VSM, TGA, XRD, and EDX techniques and applied in the synthesis of 2,4,6-triarylpyridines derivatives via four-component reaction of various benzaldehydes, acetophenones, and ammonium. The absence of solvent, high yields of products, short reaction times, mild reaction conditions, and easy work-up procedure in combination with non-toxicity, efficiency, high surface area, stability, cheapness, magnetic character, and reusability of the catalyst are noteworthy advantages of the present method.

In this research work, we have designed and introduced [Zr-UiO-66-CO₂H]Br as a versatile heterogeneous acid catalyst for the ring-opening of epoxides through S_N1 and/or S_N2 type mechanisms. In addition, the appropriate method for designing an active and efficient Bronsted acid site in metal-organic frameworks is discussed. [Zr-UiO-66-CO₂H]Br was applied for the preparation of α-aryloxy alcohols by the condensation reaction of various epoxides with phenol or thiophenols under mild and green conditions.

Individuals spend a lot of time indoors; thus, they can generally be exposed to polycyclic aromatic hydrocarbons (PAHs) such as teratogens, mutagens, and carcinogens with the potential of environmental and also human health risks. Therefore, the current study was conducted for the analysis, source identification, and health risk assessment of PAHs in household dust samples of the city of Khorramabad, Lorestan province, Iran in 2020. In so doing, 50 household dust samples were collected from 10 sampling sites. After extraction of the analytes, the gas chromatography/mass spectrometry (GC–MS) method was used to determine the PAHs contents in the samples. Sixteen priority PAHs were detected and quantified in the samples. The median values of ∑16PAHs were found to be 18.4 µg kg⁻¹. Although based on the results of molecular diagnostic ratios (MDRs), PAH compounds could be originated from both petrogenic and pyrogenic sources, the pyrogenic sources including smoking, natural gas combustion, and traffic prevailed. Total incremental lifetime cancer risks (ILCRs) of children and adults with average values of 2.07E-04 and 1.83E-04, were both classified in the 'high critical value’ category. The cancer risk levels via dermal contact (1.15E-04) and direct ingestion (9.19E-05), indicated that both routes greatly contributed to the cancer risk for children. Similarly, the risk value of dermal contact (1.17E-04) and direct ingestion (6.58E-05) were found to be important pathways that adults could be exposed to contaminated dust. Accordingly, the mean values of ILCRs ranked in the following order: dermal contact > direct ingestion > inhalation for both cases (ie, children and adults). In conclusion, to maintain the health of both the man and the environment, it is recommended that regular and periodic analyses of these pollutants in different environmental samples including soil, sediment, dust, particulate matter, air, water, and tissues of living organisms in be performed to help prevent exposure risks of PAHs.

In this work we synthesized imidazolidine derivatives in excellent yields using multicomponent reactions of phthalaldehyde or its derivatives, primary amines, isothiocyanate, 2,4-dihydroxyacetophenone and isopropenylacetylene in the presence of catalytic amount of Ag/KF/CP@MWCNTs NCs in water at room temperature. Also, the catalytic activity of the green synthesized Ag/KF/CP@MWCNTs NCs was evaluated in the reduction of organic pollutants such as 4-nitrophenol (4-NP) in water at mild conditions. The results indicated that the biosynthesized NCs have very high and effective catalytic activity for organic pollutants within few seconds. As well the antioxidant activity of some synthesized imidazolidine was studied using trapping of radical by DPPH and ferric reduction activity potential (FRAP) experiment. Also, the antimicrobial activity of some synthesized compounds proved by employing the disk diffusion test on Gram-positive and Gram-negative bacteria. Also, to better understanding reaction mechanism density functional theory (DFT) based quantum chemical methods have been applied. The short time of reaction, high yields of product, easy separation of catalyst and products are some benefits of this procedure.

An expedient, green, practical, and vastly efficient three-component cyclo-condensation is catalyzed by triphenylphosphine. The 4-arylideneisoxazol-5(4H)-one heterocycles are generated in good to excellent isolated reaction yields. Experiments show that the best results were obtained using 15 mol% of the catalyst under aqueous conditions at room temperature. The sonochemical synthesis of 4-arylideneisoxazol-5(4H)-one derivatives were also performed by using 10 mol% of triphenylphosphine in water as an eco-friendly reaction medium. In the comparative method, ultrasonication showed shorter reaction times and also requires smaller amounts of catalyst. While aryl/heteroaryl aldehydes were used, the variation of β-keto-ester was also explored. The β-keto-esters (ethyl acetoacetate/ethyl 4-chloro-3-oxobutanoate/ethyl 3-oxohexanoate) under optimized reaction conditions reacted well and afforded the corresponding 4-arylideneisoxazol-5(4H)-ones in shorter reaction times. The approach is simple, approximately compatible with the pot-, atom-, and step-economy.