The coupling of aryl or vinyl halides with terminal acetylenes catalysed by palladium and other transition metals, commonly termed as Sonogashira cross-coupling reaction, is one of the most important and widely used sp2–sp carbon–carbon bond formation reactions in organic synthesis, frequently employed in the synthesis of natural products, biologically active molecules, heterocycles, molecular electronics, dendrimers and conjugated polymers or nanostructures. This critical review focuses on developments in the Sonogashira reaction achieved in recent years concerning catalysts, reaction conditions and substrates (352 references).

Recent advances in Sonogashira reactions

Microwave food processing—A review

Efforts to use microwaves in material processing are gradually increasing. However, the phenomena associated with the processing are less understood; popular mechanisms such as dipolar heating and conduction heating have been mostly explored. The current paper reviews most of the significant phenomena that cause heating during microwave–material interaction and heat transfer during microwave energy absorption in materials. Mechanisms involved during interaction of microwave with characteristically different materials – metals, non-metals and composites (metal matrix composites, ceramic matrix composites and polymer matrix composites) have been discussed using suitable illustrations. It was observed that while microwave heating of metal based materials is due to the magnetic field based loss effects, dipolar loss and conduction loss are the phenomena associated with the electric field effects in microwave heating of non-metals. Challenges in processing of advanced materials, particularly composites have been identified from the available literature; further research directions with possible benefits have been highlighted.

Microwave–material interaction phenomena: Heating mechanisms, challenges and opportunities in material processing

Microwave heating is rapidly emerging as an effective and efficient tool in various technological and scientific fields. A comprehensive understanding of the fundamentals of microwave-matter interactions is the precondition for better utilization of microwave technology. However, microwave heating is usually only known as dielectric heating, and the contribution of the magnetic field component of microwaves is often ignored, which, in fact, contributes greatly to microwave heating of some aqueous electrolyte solutions, magnetic dielectric materials and certain conductive powder materials, etc. This paper focuses on this point and presents a careful review of microwave heating mechanisms in a comprehensive manner. Moreover, in addition to the acknowledged conventional microwave heating mechanisms, the special interaction mechanisms between microwave and metal-based materials are attracting increasing interest for a variety of metallurgical, plasma and discharge applications, and therefore are reviewed particularly regarding the aspects of the reflection, heating and discharge effects. Finally, several distinct strategies to improve microwave energy utilization efficiencies are proposed and discussed with the aim of tackling the energy-efficiency-related issues arising from the application of microwave heating. This work can present a strategic guideline for the developed understanding and utilization of the microwave heating technology.

Review on Microwave-Matter Interaction Fundamentals and Efficient Microwave-Associated Heating Strategies

Microwave-assisted synthesis of metal oxide/hydroxide composite electrodes for high power supercapacitors – A review

Effect of CO Poisoning of PEM Fuel Cell Anode on Impedance Spectra-Simulations

Electrochemical Impedance Spectroscopy (EIS) Analysis of BTA Removal by TMAH during Post Cu CMP Cleaning Process

Mechanistic Analysis of Zr Dissolution in Acidic Fluoride Media Using Electrochemical Impedance Spectroscopy

Titanium (Ti) is a lustrous transition metal which possesses excellent corrosion resistance in several aggressive environments but is attacked by acidic fluoride media. In this work, the addition of fluoride ion to nitric acid on the corrosion behavior of Ti and air-oxidized Ti was studied. Air oxidation of Ti at 800 °C for 5 h resulted in the formation of an intact rutile TiO2 layer with a thickness of about 35 μm. The corrosion resistance was investigated from the polarization resistance (
 $$R_{\text{P}}$$
 ) values which were obtained from linear polarization and electrochemical impedance spectroscopy (EIS) measurements. A decrease in the $$R_{\text{P}}$$
 value of Ti with the addition of fluoride ion in nitric acid was observed, and this indicated the formation of an unstable layer, which resulted in accelerated dissolution. The several order increase in the $$R_{\text{P}}$$
 value of air-oxidized Ti in nitric acid containing fluoride ions pointed the improved resistance to corrosion. The diffusivity of species through the air-oxidized TiO2 layer was estimated from the electrochemical equivalent circuit (EEC) analysis of EIS data. Even though the diffusivity increased by several orders with the addition of fluoride ions, air-oxidized Ti provided better protection against nitric acid containing fluoride ions than Ti. The corrosion rates of Ti and air-oxidized Ti in boiling nitric acid containing fluoride ions were also estimated from weight loss experiments. Even in boiling fluorinated nitric acid, air-oxidized Ti provided better corrosion protection, with corrosion rates of about 1000 times less than that of Ti.

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S. Ramanathan

Papers

Effect of CO Poisoning of PEM Fuel Cell Anode on Impedance Spectra-Simulations

Electrochemical Impedance Spectroscopy (EIS) Analysis of BTA Removal by TMAH during Post Cu CMP Cleaning Process

Mechanistic Analysis of Zr Dissolution in Acidic Fluoride Media Using Electrochemical Impedance Spectroscopy

Studies on Corrosion of Titanium and Air-Oxidized Titanium in Fluorinated Nitric Acid

Electrochemical Sensing Platform for the Detection of Nitroaromatics Using g-C3N4/V2O5 Nanocomposites Modified Glassy Carbon Electrode