The pairing of ions of opposite charge is one of the dogmas in chemistry and ion-pairs or ionic interactions often govern chemical reactions or more particularly such processes as synthesis or catalysis. Usually, there is no doubt that ions possess opposite charges. This is why the recent report on the existence of cation-cation pairing by […]
As the search for renewable energy sources has intensified, the discovery of efficient and cheap technologies for exploiting the energy from the sunlight has emerged as a key challenge. Higher efficiency plays an increasingly important role in making competitive solar cell designs as the price of silicon continues to drop. At present, the actual silicon […]
Lithium-ion batteries are widely used in portable electronic devices and electric vehicles since their introduction by Sony in 1991. Safety is an important concern since about two billion cells are produced every year but with a one-in-200,000 failure rate. Excessive temperature variations and high temperatures over the melting point of the metallic lithium can cause […]
¨The chemical bond¨ is one of the most often used concepts in chemistry. It is also one of the eldest terms since the first definition of chemical bond comes from the studies of G.N. Lewis who published his classical paper on interactions between atoms in 1916 . Lewis stated that ¨ we shall say that […]
Chemistry • Condensed matter • Materials • Physics • Quantum physics
Minimizing losses in any kind of electronic device is always important, but it is paramount in nanoelectronics. Still, most of the phenomena that lead to inefficiencies in the operation of these nanodevices are poorly understood. Consider the case of quantum dots. A quantum dot is a nanometric crystalline structure of semiconductor materials. In a quantum […]
In the standard representation of the periodic table, we find below two separated rows of elements. Their chemistry and electronic configuration belong to a group three element, so what these two separated rows really mean is that in this representation of the table they are all located on top lanthanum and actinium, three-dimensionally building a […]
The role of molecular hydrogen (dihydrogen) in reactions of organic and inorganic chemistry is very well known . One can mention numerous reactions playing the key role in biochemistry, like for example processes in microorganisms, or the commonly known addition of H 2 to organic compounds. It is worth to mention that dihydrogen as an […]
We are all familiar with rust. Rust is an iron oxide, usually red, formed by the reaction of iron and oxygen in the presence of water or air moisture, and it is a clear sign of metal corrosion by oxidation. Oxidation is a ubiquitous phenomenon that proceeds via the electrochemical interaction of ambient oxygen molecules […]
The current in a semiconductor consists of two parts: the negatively charged electrons in the conduction band and the positively charged holes in the valence band. Although the number of electrons in the conduction band is equal to the number of holes in the valence band, the two contributions to the current are in general […]
Organic small molecules are essential for many different fields, from medicine to technology: Most of the drugs we take, biological probes and the constituents of solar cells, to name but a few, are small organic molecules. (Figure 1) However, their synthesis in the laboratory is not easy. Individual reaction conditions for each step of the […]