Quantum chemical investigation on complexation of palladium with iminopyridyl ligands: Structural,thermochemical, and electronic aspects

The main purpose of this research is to investigate computationally the structural, thermochemical and electronic properties in complexation process of dichloride {N-[(5-methylthiophen-2-yl)methylidene]?2-(pyridine-2-yl)ethanamine-κ²N,N′}palladium(II) complex. In the first step, we have concentrated on comparative survey of ability of density functional theory (DFT) and also semi-empirical approaches to reproduce the crystal structure of palladium(II) complex. Comparison of our calculated structural parameters of aforementioned complex with the available crystallographical data reveals that both functionals (B3LYP and M06) can well-reproduce x-ray structure of the complex with a near accuracy while PM6-D2 semi-empirical calculated values are not in a reliable agreement with the crystallographical data.

In the next step, we have shown the thermodynamical superiority in using THF as a polar solventin complexation reaction via polarized continuum model (PCM) computations which is in confirmation with experimental observations. Additionally, the bond orders of some selected key bonds in C₁₃H₁₄N₂Sligand andPdCl₂(C₁₃H₁₄N₂S) complex have been evaluated comparatively to analyze the electronic behavior of coordination.

Finally, we focused on topological analysis of electron density function via quantum theory of atoms in molecules (QTAIM) approach to explore the strength and nature of metal-ligand interactions on bond and ring critical points (BCPs).Strictly speaking, QTAIM calculations have been performed to determine the electronic density, its Laplacian and other electronic energy density indicators on some key BCPs to interpret the electronic features of complexation.     

Electrochemical behaviors of novel electroactive Au nanoparticles protected by self-assembled monolayers

There has been substantial recent interest in studying monolayer-protected gold clusters (MPCs) owing to their diverse applications. The present work is an electrochemical study of novel gold nanoparticles covered with a monolayer of mercapto-dodecanol ended chloro-dicyano-quinone (HS-C12O-CDQ), which was adsorbed on the electrode (CDQ-MPCs film). Our findings reveal a redox behavior for CDQ-MPCs film similar to the solution electrochemistry of dichloro-dicyano-quinone. Furthermore, a diffusion-like mechanism was found for electron transfer, which may have occurred due to proton diffusion towards or outwards the electrode through the film casted. Chronoamperometry confirmed diffusion behavior of the ET process. Finally, EIS was used to find the rate constant of ET process for the redox reaction that occurred and the contribution of MPCs in total interfacial capacitance.     

Zinc Chloride Anhydrous as New and Effective Catalyst for Conversion of Ketones and Aldehydes to Corresponding Gem‐dihydroperoxides

Zinc chloride anhydrous has been used as an efficient and new catalyst for conversion of ketones and aldehydes to corresponding gem‐dihydroperoxides by aqueous hydrogen peroxide (30%) in room temperature with excellent yields and notable reaction times.     

BF3‐grafted Fe3O4@Sucrose nanoparticles as a highly‐efficient acid catalyst for syntheses of Dihydroquinazolinones (DHQZs) and Bis 3‐Indolyl Methanes (BIMs)

Current paper represents immobilization of sucrose on the Fe₃O₄ core and grafting of boron trifluoride (BF₃) onto the new surface. The catalytic activity of these nanoparticles was tested in syntheses of Dihydroquinazolinones (DHQZs) and Bis (3‐Indolyl) Methanes (BIMs) as two fruitful pharmaceutical structures. Acidic capacity, FT‐IR, XRD, VSM, TGA and SEM–EDX tests are carried out on such novel nanoparticles (NPs). Catalyst has shown more acidic capacity per one gram of NPs than sulfonated homologue which was reported previously.     

Magnetic Fe3O4 nanoparticles supported imine/Thiophene‐nickel (II) complex: A new and highly active heterogeneous catalyst for the synthesis of polyhydroquinolines and 2, 3‐dihydroquinazoline‐4(1H)‐ones

A new magnetically separable nickel catalyst (Ni(NO₃)_2?Imine/Thiophene‐Fe₃O₄@SiO₂) was readily prepared and structurally characterized by Fourier transform infrared spectroscopy (FT‐IR), Scanning electron microscopy (SEM), Energy‐dispersive X‐ray spectroscopy (EDX), Vibrating sample magnetometer (VSM), X‐Ray diffraction (XRD) and Atomic absorption spectroscopy (AAS). The Ni(NO₃)_2?Imine/Thiophene‐Fe₃O₄@SiO₂ exhibited efficient catalytic activity in the synthesis of 2,3‐dihydroquinazoline‐4(1H)‐ones and polyhydroquinolines. Catalysis research under water and solvent‐free conditions makes also this synthetic protocol ideal and fascinating from the environmental point of view. The catalyst can be magnetically recovered after the reaction and can be reused for many times without appreciable decrease in activity.     

Electrodeposited Ni(OH)<Subscript>2</Subscript> nanostructures on electro-etched carbon fiber paper for highly stable supercapacitors

Herein, we introduce a facile, inexpensive and fast, and additive-/template-free method to fabricate highly stable nickel hydroxide nanofibers for supercapacitor applications. Ni(OH)₂ nanofibers were electrodeposited on electro-etched carbon fiber paper by a potential step method (Ni(OH)₂-ECFs) and characterized using scanning electron microscopy and X-ray diffraction analysis. Electrochemical performance of Ni(OH)₂-ECF was studied in symmetric two-electrode assembly by cyclic voltammetry, galvanostatic charge–discharge method, and electrochemical impedance spectroscopy. A specific capacitance of 277.5 F g^?1 was achieved for the symmetric supercapacitor based on two identical Ni(OH)₂-ECFs. Our findings demonstrate high-rate capability with excellent stability (approximately 100 % capacitance retention) for Ni(OH)₂-ECF supercapacitor, originated from the intimate contact between Ni(OH)₂ and ECF. Our studies suggest the Ni(OH)₂-ECF electrode as an excellent material for supercapacitor applications.