Above room temperature spin transition in a metallo-supramolecular coordination oligomer/polymer

By use of a metallo-supramolecular concept, a linear iron(ii) coordination chain [Fe(II)(L)](n)(BF(4))(2n) (L = 1,4-bis(1,2':6',1'-bispyrazolylpyridin-4'-yl)benzene) was rationally designed and synthesized. The molecular chain shows a reversible spin transition at 323 K with a ca. 10 K wide hysteresis loop.     

Lattice-solvent controlled spin transitions in iron(II) complexes

A series of spin transition (ST) iron(II) compounds of the type [FeII2](X)2.{S}2 (where is 4'-(4'-cyanophenyl)-1,2':6'1'-bispyrazolylpyridine, X=ClO4- or BF4-, and S is acetonitrile) was synthesized and magnetically investigated. The effects of the removal of the lattice-solvent molecules and of their different positions relative to the iron(II) cations on the ST process were investigated. Crystallization yields orange block (A.{S}2) crystals of the composition [FeII()2](ClO4)2.{S}2, and two polymorphic compounds of the stoichiometry [FeII()2](BF4)2.{S}2 as red coffin (B.{S}2) and orange block (C.{S}2) crystals. The Fe-N bond distances of A.{S}2 (from 1.921(9) to 1.992(3) A; at 150 K), B.{S}2 (from 1.943(2) to 2.017(2) A; at 180 K) and C.{S}2 (from 1.883(3) to 1.962(3) A; at 180 K) indicate low spin (LS) states of the respective iron(II) ions. Notably, the observed small difference in the Fe-N distances at 180 K for the two polymorphs B.{S}2and C.{S}2 are due to different positions of the acetonitrile molecules in the crystal lattices and illustrate the sensitivity of the spin transition properties on lattice-solvent effects. Variable-temperature single crystal X-ray studies display single-crystal thermochroism (red (LS)<-->orange (HS)) for A.{S}2 and B.{S}2 and ca. 3.6% decrease in the unit cell volume of A.{S}2 from 4403 A3 at 300 K to 4278 A3 at 150 K. The temperature dependent magnetic susceptibilities of A.{S}2 and B.{S}2 demonstrate systematic increase of the spin transition temperatures (T1/2) and continuous decreases of the hysteresis loop width (DeltaT1/2) upon slow lattice-solvent exclusion.     

Electrodeposition of iron phosphide on copper substrate as conversion negative electrode for lithium-ion battery application

An attempt is made to synthesize high temperature iron phosphide phase over copper substrate at room temperature via simple and cost-effective electrodeposition technique using aqueous acidic electrolyte. The phosphorus content in alloys varied with its source's composition in the electrolyte. All as-obtained deposits are annealed at 400 °C for 3 h under constant inert gas flow rate in a tubular furnace. X-ray diffraction and scanning electron microscope are used to characterize phase composition and morphology, respectively. All samples are electrochemically tested as anode material against lithium between 0.01 and 2.5 V at constant 10 μAcm^?2, rendering it as possible negative electrode for high energy density lithium-ion battery applications.     

Aphrodisiac Performance of Bioactive Compounds from Mimosa pudica Linn.: In Silico Molecular Docking and Dynamics Simulation Approach

Plants and their derived molecules have been traditionally used to manage numerous pathological complications, including male erectile dysfunction (ED). Mimosa pudica Linn. commonly referred to as the touch-me-not plant, and its extract are important sources of new lead molecules in drug discovery research. The main goal of this study was to predict highly effective molecules from M. pudica Linn. for reaching and maintaining penile erection before and during sexual intercourse through in silico molecular docking and dynamics simulation tools. A total of 28 bioactive molecules were identified from this target plant through public repositories, and their chemical structures were drawn using Chemsketch software. Graph theoretical network principles were applied to identify the ideal target (phosphodiesterase type 5) and rebuild the network to visualize the responsible signaling genes, proteins, and enzymes. The 28 identified bioactive molecules were docked against the phosphodiesterase type 5 (PDE5) enzyme and compared with the standard PDE5 inhibitor (sildenafil). Pharmacokinetics (ADME), toxicity, and several physicochemical properties of bioactive molecules were assessed to confirm their drug-likeness property. Molecular dynamics (MD) simulation modeling was performed to investigate the stability of PDE5–ligand complexes. Four bioactive molecules (Bufadienolide (−12.30 kcal mol⁻¹), Stigmasterol (−11.40 kcal mol⁻¹), Isovitexin (−11.20 kcal mol⁻¹), and Apigetrin (−11.20 kcal mol⁻¹)) showed the top binding affinities with the PDE5 enzyme, much more powerful than the standard PDE5 inhibitor (−9.80 kcal mol⁻¹). The four top binding bioactive molecules were further validated for a stable binding affinity with the PDE5 enzyme and conformation during the MD simulation period as compared to the apoprotein and standard PDE5 inhibitor complexes. Further, the four top binding bioactive molecules demonstrated significant drug-likeness characteristics with lower toxicity profiles. According to the findings, the four top binding molecules may be used as potent and safe PDE5 inhibitors and could potentially be used in the treatment of ED.     

Electrochemically Generated Copper(I)-Catalyzed Click Chemistry: Triazole Synthesis and Insights into Their Photophysical Properties

Herein, we report the electro-click (e-CLICK) reaction via electrochemically generated copper(I) catalytic species. The reaction worked under constant potential electrolysis (−0.25 V) with copper(II) nitrate and 2,2′-bipyridine serving as pre-catalyst and ligand respectively. The reaction accommodates electronically different organic azides and terminal alkynes to afford 1,2,3-triazoles in good synthetic yields with excellent 1,4-regioselectivity. Compared to traditional click chemistry, the developed e-CLICK methodology avoids the use of external reducing agents such as sodium ascorbate. Absorptive properties of selected triazole products were assessed by UV-visible electronic spectra. Triazole ( 3 e ) was further applied for the spectrophotometric detection of Co²⁺ and Cu²⁺ species.