Synthesis,crystal structure and Hirshfeld surface analysis of a new 0D nanostructured [{Ar-Cl)tetra-azo-S}2Hg] coordination supramolecular compound derived from phenyl isothiocyanate ligand

Abstract

Nanoparticles of a new mercury(II) coordination supramolecular compound (CSC), [{(Ar-Cl)tetra-azo-S}₂Hg] (1), were synthesized using a sonochemical process and characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and elemental analyses (EA). The single crystal X-ray data of 1 revealed that the Hg ion was two-coordinate. Also, Hirshfeld surface analysis of 1 showed the effective role of interactions related to nitrogen atoms in stabilization of the supramolecular structure. The role of ultrasonic power, sonicating time and temperature on the size and morphology of the nano-structured compound obtained from 1 were investigated. The results indicated that increasing temperature and sonication power and decreasing sonication time led to reducing the particle size.     

分子筛催化下环氧氯丙烷开环反应的溶剂效应

环氧化合物与羧酸的开环加成酯化是有机化学中一类重要反应,开环形成的羧酸β-羟基酯有着十分广泛的用途。这类反应的进行通常需要高活性的催化剂,我们曾将Fe(Ⅲ)改性的ZSM-5分子筛应用于羧酸β-羟基酯的合成。本文用Fe-ZSM-5分子筛为催化剂,以环氧氯丙烷与丙酸反应作为模型,研究了取代苯为溶剂时对反应速率的影响,发现反应的速率     

One-pot synthesis,X-ray crystal structure,and identification of potential molecules against COVID-19 main protease through structure-guided modeling and simulation approach

Although antimicrobial resistance before the Covid-19 pandemic is a top priority for global public health, research is already ongoing on novel organic compounds with antimicrobial and antiviral properties in changing medical environments in connection with Covid 19. Thanks to the Biginelli reaction, which allows the synthesis of pyrimidine compounds, blockers of calcium channels, antibodies, antiviral, antimicrobial, anti-inflammatory, or antioxidant therapeutic compounds were investigated. In this paper, we aim to present Biginelli's synthesis, its therapeutic properties, and the structural–functional relationship in the test compounds that allows the synthesis of antimicrobial compounds. Both the DFT and TD-DFT computations of spectral data, molecular orbitals (HOMO, LUMO) analysis, and electrostatic potential (MEP) surfaces are carried out as an add-on to synthetic research. Hirshfeld surface analysis was also used to segregate the different intermolecular hydrogen bonds involved in the molecular packing strength. Natural Bond Orbital (NBO) investigation endorses the existence of intermolecular interactions mediated by lone pair, bonding, and anti-bonding orbitals. The dipole moment, linear polarizability, and first hyperpolarizabilities have been explored as molecular parameters. All findings based on DFT exhibit the best consistency with experimental findings, implying that synthesized molecules are highly stable. To better understand the binding mechanism of the SARS-CoV-2 M^pro, we performed molecular docking, molecular dynamics (MD) simulations, and binding free energy calculations.     

Two novel trinuclear cluster-based coordination polymers with 2,6-Di-imidazol-1-yl-pyridine: solvothermal syntheses,crystal structures,properties and Hirshfeld surface analysis

Two novel trinuclear cluster-based coordination polymers {[M₃(dip)(AcO)₆]·(X)}_n (1, M = Cu, X = CH₃OH; 2, M = Co, X = 2H₂O) (dip is 2,6-Di-imidazol-1-yl-pyridine), have been synthesised and structurally determined by single crystal X-ray diffraction, element analysis. Crystallographic unit of 1 consists of three Cu(II), six acetic ions, one dip ligand and one methanol molecule, which formed 1D chain through acetic bridges. The 1D chain further constructed 2-D network through dip ligand bridge which formed 3-D network through π···π interaction. Crystallographic unit of 2 consists of three Co(II), six acetic ions, one dip ligand and two water molecules. The trinuclear unit further formed a dimmer through dip ligand bridge which constructed 1-D through dip ligand bridge. The 1D chain further constructed 2-D network through π···π interaction. IR and UV–vis spectrum properties of 1 and 2 were studied. In addition, Hirshfeld surface analysis was also studied for 1.     

A New Non-centrosymmetric Microporous Fluorinated Iron Phosphate: Structural Elucidation,Spectroscopic Study and Hirshfeld Surface Analysis

The crystal structure of a new non-centrosymmetric microporous fluorinated iron phosphate, (H₃O)₂[Fe₄(H₂O)₂F₄(PO₄)₂(HPO₄)₂](H₂O), was determined by single crystal X-ray diffraction analysis and the result reveals that it belongs to the orthorhombic system with four molecules in the unit cell(space group P2₁2₁2₁). Thus, the complex was characterized by powder X-ray diffraction, spectroscopic techniques(Fourier transform infrared and Fourier transform Raman) and ¹⁹F MAS NMR. The elemental analysis of the sample was also carried out. The chiral inorganic sheets, which stacked along[100] showed the presence of FeF₂O₄ as well as FeF₂O₃H₂O octahedra, PO₄ besides HPO₄ tetrahedra, hydronium ions(H₃O⁺) and isolated water molecules. Hirshfeld surface analysis, especially d_nom surface and fingerprint plots, were used for decoding the intermolecular interactions in the crystal network and the contribution of component units for the construction of the 3D architecture. From the Hirshfeld surfaces and 2D fingerprint analysis, it was found that the subtle interactions, such as H…H associating the third intense interaction of all intercontacts, provide extra stabilization in addition to the presence of the strong hydrogen bonds mentioned above.     

糖基修饰大环化合物的研究进展

糖类分子作为生命过程中多种特殊受体的底物,在生物信息传递中发挥着重要的作用.近年来,已通过各种方法高效率地制备了一些新型的糖基修饰的杯芳烃、环糊精和冠醚等大环分子,它们在生物凝集素特异性识别、选择性离子识别及手性催化等方面的应用引起了研究者的广泛兴趣.本文从糖基修饰大环分子的合成、功能化及其相关应用方面综述了目前糖基功...     

Solvent effects on chemical processes. 4. Complex formation between naphthalene and theophylline in binary aqueous-organic solvents

The standard free energy change for complex formation is written as a sum of effects arising from solvent-solvent interactions (the general medium effect), solvent-solute interactions (the solvation effect), and solute-solute interactions (the intersolute effect). The general medium effect is given by gA(–_o), where g is a curvature correction factor to the solvent surface tension , A is the change in surface area as the two solvent cavities containing the substrate (naphthalene) and ligand (theophylline) collapse into a single cavity containing the complex, and _o is the value of surface tcnsion at which there is no net solvophobic interaction; is defined to be the value appropriate to the equilibrium mean solvation shell composition. The solvation effect is modeled by equilibrium stoichiometric formation of solvated species. All data are related to the fully aqueous system to give _MG^o, the solvent effect on the free energy change, as an explicit function of solvent composition. Solvent effects on bimolecular association are related to solvent effects on the solubilities of the substrate, ligand, and complex. Approximation methods for interpreting such systems are described and are applied to the naphthalene-theophylline complex. It is shown that complex destabilization in mixed aqueous-organic solvents (relative to the fully aqueous system) may receive contributions from both the general medium and the solvation effects, and that these contributions can be quantitatively estimated.     

三维氢键超分子化合物[H3cth][Fe(CN)6]·3H2O的合成与结构

用内消旋５,７,７,１２,１４,１４－六甲基－１,４,８,１１－四氮杂环十四烷（ｃｔｈ）和Ｋ_３［Ｆｅ（ＣＮ）_６〕合成了氢键连接的超分子化合物［Ｈ_３ｃｔｈ］［Ｆｅ（ＣＮ）_３］·３Ｈ_２Ｏ．该化合物的晶体属三斜晶系,Ｐ－１空间群,晶胞参数ａ＝０．９３０ ９７（９）ｎｍ,ｂ＝１．０５１ ６０（１１）ｎｍ,ｃ＝１．６３８ ４７（１７）ｎｍ,ａ＝１０１．０７７（２）°,β＝９０．８６０（２）°,γ＝１１１．６７１（２）°, Ｖ＝１．４５６ ４（３） ｎｍ３, Ｚ＝２, Ｒ＝０．０４１５．晶体中质子化的大环四胺与六氰合铁（Ⅱ ）离子之间通过氢键连接成二维层状结构,而水分子所形成的氢键使化合物呈现三维超分子网络．     

Solvent‐Free Sonochemical Synthesis and Antifungal Activity of 1‐Alkyl‐3‐Methylimidazolium Bromide [RMIM]Br Ionic Liquids

In view of the continuous threat of opportunistic fungal infections to human health and the emerging importance of ionic liquids in therapeutic applications, we report the efficient one‐pot synthesis of a series of 1‐alkyl‐3‐methylimidazolium bromide [RMIM]Br ionic liquids through an ultrasound‐assisted reaction of 1‐methylimidazole and alkyl bromides (RBr) under solvent‐free conditions. High product yields were obtained for all syntheses (>95%) under mild conditions (2‐5 hours at 20‐40 °C). The success of the synthetic method was confirmed through ¹H‐NMR, ¹³C‐NMR and FT‐IR spectroscopy. All products exhibited activity against the fungus C. albicans with clotrimazole and water as positive and negative controls, respectively. At a concentration of 1%, [OMIM]Br IL exhibited an antimycotic activity with an index of 1.5 which is comparable to that of 1% clotrimazole having an antimicrobial index of 1.3, signifying the potential of the product as a fungal growth inhibitor. Structure‐Activity Relationship (SAR) studies showed that an increase in the alkyl chain length corresponds to an increase in the antifungal activity of the ionic liquids.     

两个salen型卤代希夫碱Ni(Ⅱ)配合物的合成、晶体结构及Hirshfeld表面分析

通过硝酸镍与卤代希夫碱在甲醇溶液中反应,合成了2个Ni（Ⅱ）希夫碱配合物[Ni（3,5-Cl-salcy）]（1）和[Ni（3-Cl-salcy）]（2）,（3,5-Cl-salcyH₂=N,N′-（±）-双（3,5-二氯水杨基）-1,2-环己二胺; 3-Cl-salcyH₂=N,N′-（±）-双（3-氯水杨基）-1,2-环己二胺）。通过X射线衍射测定了2个配合物的结构。结构分析表明2个配合物的基本单元均为Ni（Ⅱ）离子通过与希夫碱配体的[N₂O₂]原子配位构成相似的平面型单核配合物。Platon软件分析表明配合物1中并不存在任何氢键,配合物2也仅存在非经典氢键。通过Hirshfeld表面分析法对2个配合物晶体结构中弱交换作用的分析结果表明,虽然卤原子构成的氢键相对较弱,但是C-H…X在稳定三维超分子晶体结构中起着非常重要的作用;此外,通过2个配合物的对比发现,配体中卤原子数量的不同对于晶体中弱交换作用的占比可以起到非常重要的影响。     

多卤素取代的salamo型锰(Ⅱ)配合物:合成、晶体结构、Hirshfeld分析及荧光性质

在有机溶剂中,通过卤素取代的salamo型双肟配体H₂L¹（4,4'',6,6''-tetrachloro-2,2''-（ethylenediyldioxybis（nitrilomethylidyne））diphenol）,H₂L¹（5-nitro-4'',6''-dichloro-2,2''-（ethylenedioxybis（azomethine））diphenol）和四水合乙酸锰（Ⅱ）反应,合成了2个锰（Ⅱ）配合物[Mn（L¹）（H₂O）₂]（1）和[Mn（L²）（H₂O）₂]·0.37H₂O（2）,并通过元素分析、红外光谱、紫外-可见吸收光谱、单晶X射线衍射、荧光光谱和Hirshfeld表面分析对2个锰（Ⅱ）配合物进行了表征。X射线晶体学结果表明2个配合物中的锰（Ⅱ）原子都是六配位的,其中salamo型配体的N₂O₂占据平面位置,2个配位水分子占据轴向位置,形成了扭曲的八面体几何构型。由于存在较丰富的氢键相互作用,在配合物1和2中分别形成了无限的一维和二维超分子结构。     

Crystal structure analysis,Hirshfeld surface analysis,spectral investigations (FT-IR,FT-R), DFT calculations,ADMET studies and molecular docking of 3H-Methyl-1H-pyrazole-1-carboxamide (3MPC)

On 3H-Methyl-1H-pyrazole-1-carboxamide (3MPC), Single crystal XRD, Fourier Transform Infrared Spectroscopy, Fourier Transform Raman Spectroscopy, Molecular Electrostatic Potential, Density function theoretical analysis and Molecular docking analysis are conducted. The target protein docking experiments revealed that the small molecule (MET) is a good molecule that docks well with several Nav channel 1 targets. Molecular Electrostatic Potential (MEP) aids in the optimization of protein-ligand electrostatic interactions. The molecular surface and hydrogen bonding interactions in the 3MPC crystal structure were located and analyzed using a fingerprint plot and Hirshfeld Surfaces. DFT–B3LYP calculations with the 6-31G (d,p) basis set are used to establish the optimised structure of the MET molecule, and the measured vibrational frequencies are compared to experimental values. The parameters of absorption, distribution, metabolism, excretion (ADME) and toxic (Tox) were assessed using the online server preADMET.     

甲基炔诺酮的荧光分析法研究

基于甲基炔诺酮与浓H2 SO4反应后水解产物的荧光性质 ,建立了一种测量甲基炔诺酮的荧光光度分析新方法。系统地研究了甲基炔诺酮与浓H2 SO4的反应条件及三碳以下的低级醇对产物荧光性质的影响。本法检测限为 1 89×1 0 - 7mol·L- 1 ,荧光强度与浓度在 0mol·L- 1 ～ 1 2 8× 1 0 - 5mol·L- 1 范围内呈良好线性关系 ,方法相对标准偏差为 1 7%     

High precision trace analysis in capillary gas-liquid chromatography using an inlet based on the static solvent effect

A sample inlet, based on the static solvent effect has been designed and constructed. The inlet can handle samples up to 20 μl which allows for the detection, using an F. I. D., of constituents in the parts per billion range. The reproducibility of the inlet in terms of peak percentage area is around 1% relative standard deviation over a range of chemical types.     

Kinetic Studies of Solvent and Pressure Effects on the Thermal Isomerization of Palladium Dithizonate

IntroductionThe photo-and thermo-chromisms of organometallic compounds have been intensivelystudied during thelast1 0 years.Meriwetheretal.[1 ,2 ] examined the chromic behaviorofmet-al-dithizone(phenyldiazenecarbothionic acid2 -phenylhydrazide) complexesin detail.From thekinetic and infrared studies,they showed thatthe central metal of a dithizonate complex de-termined the photochemical stability,the rate of the thermal return reaction,and the colorofthe dithizonate complex.As reported by Mer…