Graphene nanoribbons (GNRs), are strips of graphene with ultra-thin width (<50 nm). Graphene ribbons were introduced as a theoretical model by Mitsutaka Fujita and coauthors to examine the edge and nanoscale size effect in graphene. GNRs are very interesting structures, partly due to their attractive electronic properties. Those properties vary dramatically with changes in the […]
During World War II the Germans relied on their strong chemical knowledge to overcome the limited access to critical raw materials that the circumstances of the war itself imposed. One of these raw materials was Chilean saltpeter (sodium nitrate), which was the base for explosives. The solution was to use a chemical process designed to […]
Gold is the quintessential noble metal. Its lack of chemical reactivity, particularly to acids and atmospheric corrosion, together with is rarity and malleability make it the precious metal it is since ancient times. Today, if we go for a description of gold in a chemistry textbook, we find something similar to this: A soft yellow […]
When autumn arrives to temperate climate forests, deciduous trees lose their characteristic green tonalities and start showing a wide spectrum of new colours: yellow, brown, orange, red… Chlorophyll reabsorption takes place in the leaves and carotenoids, present in a lower concentration, are exposed. These pigments are produced in all photosynthetic organisms, fungi and non-photosynthetic bacteria […]
Imagine a very simple chemical estructure: 4 carbon and 1 nitrogen forming a ring, with no double bonds, just simple bonds between any two of them and with hydrogen. This compound is called pyrrolidine and is the base of very important biological and farmacological products. Pyrrolidine is found naturally in the leaves of tobacco and […]
Biochemistry • Chemistry • Condensed matter • Molecular biology
Nanopore DNA sequencing was one the ten scientific breakthroughs of 2016 highlighted by Science magazine. In principle, graphene is the perfect pore material for DNA sequencing . Its monoatomic thickness of 0.35 nm is similar to the DNA base spacing and graphene nanopores can be fabricated with a diameter of only 1.0 nm, about the […]
Chemistry • Condensed matter • Materials • Physics • Quantum physics
Faster. That is the word that describes de evolution of electronics. Any new development has to be faster than anything before, if it is going to cope with the huge amount of information that the device where it may be incorporated will have to process in almost no time. Graphene has just demonstrated once again […]
Carbon has four valence electrons. To fill its octet, it requires four additional electrons, which can be obtained through the formation of four covalent bonds. Carbon forms single, double, and triple bonds to achieve a filled octet. As a result, carbon can have a tetrahedral, trigonal planar, or linear geometry, respectively. A unique feature of […]
Today is Monday morning and I am going to my laboratory in Niteroi by ferryboat. I took it from the XV Square of Rio de Janeiro. I am looking through the window of the ferryboat and I see one of the most beautiful pictures of the city – the Guanabara Bay (GB). Cariocas (people from […]
Enediynes are organic compounds containing two triple bonds and one double bond. The enediyne groups in those compounds are often called warheads. Why this name? Because, many of these compounds are capable of undergoing Bergman cyclization or, in other words, if heated they form a ring compound from a chain by formation of a new […]