Scandium arene inverted-sandwich complexes supported by a ferrocene diamide ligand

The synthesis and characterization of the first scandium arene inverted-sandwich complexes supported by a ferrocene diamide ligand (NN(fc)) are reported. Through the use of (NN(fc))ScI(THF)(2) as a precursor and potassium graphite (KC(8)) as a reducing agent, the naphthalene and anthracene complexes [(NN(fc))Sc](2)(μ-C(10)H(8)) and [(NN(fc))Sc](2)(μ-C(14)H(10)), respectively, were synthesized and isolated in moderate to high yields. Both molecular structures feature an inverted-sandwich geometry and exhibit short Fe-Sc distances. DFT calculations were employed to gain understanding of the electronic structures of these new scandium arene complexes. A variable-temperature NMR spectroscopic study of [(NN(fc))Sc](2)(μ-C(14)H(10)) indicated that two different structures are accessible in solution. Reactivity studies showed that the naphthalene complex [(NN(fc))Sc](2)(μ-C(10)H(8)) can be converted to the corresponding anthracene species [(NN(fc))Sc](2)(μ-C(14)H(10)) and that [(NN(fc))Sc](2)(μ-C(10)H(8)) can act as either a reductant or a proton acceptor. The reaction of [(NN(fc))Sc](2)(μ-C(10)H(8)) with excess pyridine led to a rare example of C-C bond formation between two pyridine rings at the para position.     

A new method for characterizing the interphase regions of carbon nanotube composites

The elastic properties of a carbon nanotube (CNT) reinforced composite are affected by many factors such as the CNT–matrix interphase. As such, mechanical analysis without sufficient consideration of these factors can give rise to incorrect predictions. Using single-walled carbon nanotube (SWCNT) reinforced Polyvinylchloride (PVC) as an example, this paper presents a new technique to characterize interphase regions. The representative volume element (RVE) of the SWCNT–PVC system is modeled as an assemblage of three phases, the equivalent solid fiber (ESF) mimicking the SWCNT under the van der Waals (vdW) forces, the dense interphase PVC of appropriate thickness and density, and the bulk PVC matrix. Two methods are proposed to extract the elastic properties of the ESF from the atomistic RVE and the CNT-cluster. Using atomistic simulations, the thickness and the average density of interphase matrix are determined and the elastic properties of amorphous interphase matrix are characterized as a function of density. The method is examined in a continuum-based three-phase model developed with the aid of molecular mechanics (MM) and the finite element (FE) method. The predictions of the continuum-based model show a good agreement with the atomistic results verifies that the interphase properties of amorphous matrix in CNT-composites could be approximated as a function of density. The results show that ignoring either the vdW interaction region or the interphase matrix layer can bring about misleading results, and that the effect of internal walls of multi-walled carbon nanotubes (MWCNTs) on the density and thickness of the dense interphase is negligible.     

Synthesis,Characterization and Fluorescence Properties of Novel Porous Fe/ZnO Nano-Hybrid Assemblies by Using Berberis thunbergii Extract

Journal of Fluorescence - In this work, novel Fe/ZnO nanocomposites (NCs) and Fe nanoparticles loaded onto porous ZnO nanostructures have been synthesized via a simple biotechnological route by...     

The numerical simulation and sensitivity analysis of a non-Newtonian fluid flow inside a square chamber exposed to a magnetic field using the FDLBM approach

Journal of Thermal Analysis and Calorimetry - This paper simulated the free convective heat transfer (CHT) and generation of entropy (GOE) of a non-Newtonian fluid (NNF) in a square chamber using...     

Progress and Perspectives on Promising Covalent-Organic Frameworks (COFs) Materials for Energy Storage Capacity

In recent years, a new class of highly crystalline advanced permeable materials covalent-organic frameworks (COFs) have garnered a great deal of attention thanks to their remarkable properties, such as their large surface area, highly ordered pores and channels, and controllable crystalline structures. The lower physical stability and electrical conductivity, however, prevent them from being widely used in applications like photocatalytic activities and innovative energy storage and conversion devices. For this reason, many studies have focused on finding ways to improve upon these interesting materials while also minimizing their drawbacks. This review article begins with a brief introduction to the history and major milestones of COFs development before moving on to a comprehensive exploration of the various synthesis methods and recent successes and signposts of their potential applications in carbon dioxide (CO₂) sequestration, supercapacitors (SCs), lithium-ion batteries (LIBs), and hydrogen production (H₂-energy). In conclusion, the difficulties and potential of future developing with highly efficient COFs ideas for photocatalytic as well as electrochemical energy storage applications are highlighted.     

Total synthesis of achlisocoumarins I-II from Achlys triphylla

A concise and efficient total synthesis of achlisocoumarin I-II has been completed featuring a construction of the isocoumarin skeleton in a single step and the geranyl coupling with bromoarene ring at −10 °C exclusive of any chelating ligand.