نشریه پژوهش های شیمی
سال پنجم شماره 2 (پیاپی 9، پاییز و زمستان 1401)

Due to the chemical and biological threats caused by terrorist attacks, the need to develop creative and practical materials to design new materials with high capability and efficiency in absorbing and destroying chemical agents of phosphorus and sulfur in place seems necessary to threaten the health of military personnel and prevent civilians from these factors. In this paper, PAN/[POMo] composite nanofibers were prepared using electrospinning process in environmental conditions after optimizing various parameters and affecting nanofibers with an average diameter of about 150 nm. The nanofibers are capable of degrading 2-chloroethyl ethyl sulfide and diethyl cyanophosphonate at room temperature so that 2-chloroethyl ethyl sulfide in the presence of these nanofibers and hydrogen peroxide after about 2 min with 100% efficiency and selectivity to 2-chloroethyl ethyl sulfoxide. Diethyl cyanophosphate as a neurotransmitter in the presence of these nanofibers was decomposed into non-toxic compounds after about 7 minutes with an efficiency of about 98%. PAN/[POMo] nanofibers showed the ability to be reused in eight successive reaction steps in the degradation of chemical agents without any reduction in efficiency.

In this investigation, density functional theory calculations were used to compare the CO substitutions reaction of the Cp (Cp=C5H5) and indenyl(Indenyl=C7H9) ligands in the complexes (ƞ5-C5H5) Fe (CO)2(ƞ1-C5H5) (I), (ƞ5-C5H5) Fe (CO)2(ƞ1-indenyl) (II), (ƞ5-indenyl) Fe (CO)2(ƞ3-indenyl) (III). The reaction dissociation of carbonyl ligands leads to the formation of sandwich complexes Fe(η5-C5H5)2, Fe (η5-C5H5) (η5-indenyl) and Fe (η5-indenyl)2. The activation energy barrier of CO substitutions reaction was calculated for complexes I, II and III. Our calculations show that he activation energy barrier in the first and second CO substitution reactions in complexes II and III is higher than in complex I which indicate that the pair of π - bonded electron in the ƞ3-indenyl ligand has less Nucleophilic properties than the ƞ3- cyclopentadienyl ligand. In addition, calculations show that the monocarbonyl complexes are stable in the exo form and the CO substitution by endo ƞ3-indenyl form never happens.

In this study, two zirconium-based metal-organic frameworks (MOF) named UiO-66 and UiO-66(NH2) were synthesized and characterized through Fourier transform infrared (FT-IR), powder X-ray diffraction (PXRD) and N2 sorption/desorption (BET) analysis. Beside these MOFs, dimethyl 4-nitrophenylphosphate (DMNP) as a nerve agent simulant was synthesized and characterized via ultraviolet-visible (UV-Vis) spectroscopy and nuclear magnetic resonance (NMR). Due to its properties and structure similarity to phosphorus nerve agents, DMNP was selected as a less toxic alternative model, to investigation the ability of prepared MOFs for nerve agent removal. UV-Vis spectroscopy was used to monitor the DMNP concentration during the removal process. The results showed that UiO-66 and UiO-66(NH2) display high ability in catalytically hydrolysis of DMNP in the aqueous solution and neutral buffer. The removal percentage (R%) of DMNP from the organic medium was also studied and the results showed that the removal R% of 50 mL of DMNP (50 ppm) were about 76.5 and 66.8% for UiO-66 and UiO-66(NH2), respectively. Examination of the stability of the adsorbents after the adsorption process by the PXRD technique also showed that the adsorbents are recyclable.

In recent years, the synthesis of heterocyclic compounds with biological and pharmacological activities has received much attention In this work, a mesoporous zirconium‐based metal-organic framework (MOF), namely NU-1000 (NU stands for Northwestern University) with a BET surface area of 2100 m2/g was prepared via solvothermal reaction of zirconium chloride, 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene (H4TCPPy) and benzoic acid in dimethylformamide. The structure was characterized by scanning electron microscopy, powder X-ray diffraction, N2 adsorption-desorption and thermogravimetric analysis. Then, due to the high porosity, remarkable thermal and chemical stability of the Zr4+ based MOF, it was used as an heterogeneous catalyst for the synthesis of 2,3-dihydroquinazilin-4(1H)-ones as core structural unit in various biologically active compounds, employing three-component reactions of isatoic anhydride with primary amines (or ammonium acetate) and aldehydes under thermal solvent-free conditions. The solid was stable and reused several times without the loss of any activity in the process. The nanostructure framework consists of octahedral Zr6 clusters with open accessible zirconium Lewis acidic sites. Based on our knowledge, this is the first report on the three-component synthesis of quinazilin-4(1H)-ones by using a mesoporous zirconium metal-organic framework as heterogeneous catalyst.

The chemistry of cyclometalated organometallic compounds is of great current interest, on the basis of applications of such compounds in stoichiometric or catalytic organic synthesis and in sensing and functional materials . As in other areas of organometallic chemistry, studies of the cyclometalation of platinum complexes have given many interesting complexes as well as new insight into the mechanisms of the reactions. 2-Phenypyridine (abbreviated as HC^N) and biphosphines (PP) are two of the most common and important classes of ligands employed in organometallic chemistry. The cyclometalated organoplatinum(II) complexes with chelating bis (diphenylphosphino) ethane [Pt (κ1-C-C^N) R (dppe)], 2, in which C^N is ppy ( deprotonated 2-phenylpyridine) were reacted with dimethylplatinum complex [Pt Me2 (dmso)2], 3, to give [Pt (C^N) R (dmso)], 1’, and [Pt Me2 (dppe)], 4. The reaction was studied by multinuclear NMR spectroscopy and the reaction pathway and mechanism of this dppe migration was proposed and confirmed by DFT calculations.

Uremic pruritus is a frequent symptom in patients with chronic kidney disease, which affects about one-third of dialysis patients and greatly reduces their quality of life. Using drugs derived from natural plants can be an alternative way to limit and treat uremic pruritus in kidney patients. This research was conducted to evaluate the antipruritic potential of bioactive compounds of Bitter orange. A molecular docking simulation was performed on the nine natural components of Bitter orange against the active binding sites of four protein receptors related to the itching mechanism. The results showed that the selected compounds could inhibit kappa-opioid receptors 4DJH, 6VI4, 6B73, and G protein-coupled receptor 5ZTY well and have a stronger inhibitory effect compared to the anti-itch drug Gabapentin. According to the binding scores (DS) ranging from -8.72 to -4.88, and inhibition constants (Ki), the best antipruritic activities belong to Nobiletin, Caryophyllene, Naringenin, and Tangeretin ligands. The binding results showed that the natural compounds of orange could be considered a valuable source for inhibiting uremic pruritus.