A catalyst is a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change. As the catalyst itself takes part in the reaction it may undergo a physical change. Metal complexes are typically regarded as catalysts that convert organic substrates into more valuable compounds; however, to date, catalytic transformations […]
There are chemical compounds, called isomers, that have the same molecular formulae but different molecular structures or different arrangements of atoms in space. In constitutional isomerism the molecules have different molecular structures: i.e., they may be different types of compound, or they may simply differ in the position of the functional group in the molecule […]
Proteins can perform a huge number of biological functions with amazing efficiency. In order to achieve these different functions, proteins rely on the precise 3D arrangement of functional groups which are referred to as the protein fold. Some of these functions include acting as a catalyst in biochemical reactions; in these cases proteins are called […]
Environmental problems and energy resources make it vitally important for the chemical industry to develop more sustainable and less polluting processes. Therefore, using solar energy is one of the most promising alternatives. If we take a look at Nature’s energetic profile, plants are able to use solar energy to convert it into chemical energy and […]
We usually take for granted that aromaticity is something that belongs to the ground state of a molecule; but the fact is that nothing forbids aromaticity appearing in an excited state. In the same way that molecular properties are largely affected by the ground-state aromaticity, excited-state aromaticity can guide the understanding of excited-state processes, the […]
One of the unique features of the chemistry of carbon (and, to some extent, silicon) is its ability to form long chains of atoms. Polymers are substances that have macromolecules composed of many repeating units (known as ‘mers’). Many naturally occurring substances are polymers, including rubber and many substances based on glucose, such as the […]
As bea u tiful as it is, the natural world has always been a tough place to live in. Since their dawn, nearly 4 billion years ago, living organisms have faced a myriad of threats to their existence which have seen the majority of those who ever existed to perish. Only those organisms that managed […]
Packaging is essential to preserve the food quality and safety and to extend the shelf life of the stored product reducing the food waste. In this sector, plastics are the material of choice because they are cheap, lightweight and easy to process. The main requirement for packaging materials is to maintain the food in good […]
If a nucleus has a nonzero spin, it behaves as a small magnet. Therefore, in an external magnetic field, the nuclear magnetic moment vector precesses about the field direction but only certain otientations are allowed by quantum rules. Thus, for hydrogen (spin 1/2) there are two possible states in the presence of a field, each […]
Many aromatic compounds can be made into organic semiconductors by doping them with a substance such as iodine, thereby producing mobile carriers of electric charge. This is analogous to the doping of silicon in an ordinary semiconductor. The benefits of using organic compounds are evident, namely, the resources are available everywhere, extremely cheap, and there […]