Femtochemistry is the area of physical chemistry that studies chemical reactions on extremely short timescales (approximately 10−15 seconds or one femtosecond, hence the name) in order to study the very act of atoms within molecules (reactants) rearranging themselves to form new molecules (products). In a 1988 issue of the journal Science, Ahmed Hassan Zewail published an article using this term for the first time, stating "Real-time femtochemistry, that is, chemistry on the femtosecond timescale...".[1] Later in 1999, Zewail received the Nobel Prize in Chemistry for his pioneering work in this field showing that it is possible to see how atoms in a molecule move during a chemical reaction with flashes of laser light.[2]
Application of femtochemistry in biological studies has also helped to elucidate the conformational dynamics of stem-loop RNA structures.[3][4]
Many publications have discussed the possibility of controlling chemical reactions by this method,[clarification needed] but this remains controversial.[5] The steps in some reactions occur in the femtosecond timescale and sometimes in attosecond timescales,[6] and will sometimes form intermediate products. These reaction intermediates cannot always be deduced from observing the start and end products.
https://en.wikipedia.org/wiki/Femtochemistry
Nanochemistry is the combination of chemistry and nano science. Nanochemistry is associated with synthesis of building blocks which are dependent on size, surface, shape and defect properties. Nanochemistry is being used in chemical, materials and physical, science as well as engineering, biological and medical applications. Nanochemistry and other nanoscience fields have the same core concepts but the usages of those concepts are different.
The nano prefix was given to nanochemistry when scientists observed the odd changes on materials when they were in nanometer-scale size. Several chemical modification on nanometer scaled structures, approves effects of being size dependent.
Nanochemistry can be characterized by concepts of size, shape, self-assembly, defects and bio-nano; So the synthesis of any new nano-construct is associated with all these concepts. Nano-construct synthesis is dependent on how the surface, size and shape will lead to self-assembly of the building blocks into the functional structures; they probably have functional defects and might be useful for electronic, photonic, medical or bioanalytical problems.
Silica, gold, polydimethylsiloxane, cadmium selenide, iron oxide and carbon are materials that show the transformative power of nanochemistry. Nanochemistry can make the most effective contrast agent of MRI out of iron oxide (rust) which has the ability of detecting cancers and even killing them at their initial stages. Silica (glass) can be used to bend or stop light in its tracks. Developing countries also use silicone to make the circuits for the fluids to attain developed world's pathogen detection abilities. Carbon has been used in different shapes and forms and it will become a better choice for electronic materials.
Overall, nanochemistry is not related to the atomic structure of compounds. Rather, it is about different ways to transform materials into solutions to solve problems. Chemistry mainly deals with degrees of freedom of atoms in the periodic table however nanochemistry brought other degrees of freedom that controls material's behaviors.[1]
Nanochemical methods can be used to create carbon nanomaterials such as carbon nanotubes (CNT), graphene and fullereneswhich have gained attention in recent years due to their remarkable mechanical and electrical properties.
https://en.wikipedia.org/wiki/Nanochemistry
Supramolecular chemistry refers to the area of chemistry concerning chemical systems composed of a discrete number of molecules. The strength of the forces responsible for spatial organization of the system range from weak intermolecular forces, electrostatic charge, or hydrogen bonding to strong covalent bonding, provided that the electronic coupling strength remains small relative to the energy parameters of the component.[1][2][page needed] Whereas traditional chemistry concentrates on the covalent bond, supramolecular chemistry examines the weaker and reversible non-covalent interactions between molecules.[3] These forces include hydrogen bonding, metal coordination, hydrophobic forces, van der Waals forces, pi–pi interactions and electrostaticeffects.[4]
Important concepts advanced by supramolecular chemistry include molecular self-assembly, molecular folding, molecular recognition, host–guest chemistry, mechanically-interlocked molecular architectures, and dynamic covalent chemistry.[5] The study of non-covalent interactions is crucial to understanding many biological processes that rely on these forces for structure and function. Biological systems are often the inspiration for supramolecular research.
https://en.wikipedia.org/wiki/Supramolecular_chemistry
Combinatorial chemistry comprises chemical synthetic methods that make it possible to prepare a large number (tens to thousands or even millions) of compounds in a single process. These compound libraries can be made as mixtures, sets of individual compounds or chemical structures generated by computer software.[1] Combinatorial chemistry can be used for the synthesis of small molecules and for peptides.
Strategies that allow identification of useful components of the libraries are also part of combinatorial chemistry. The methods used in combinatorial chemistry are applied outside chemistry, too.
https://en.wikipedia.org/wiki/Combinatorial_chemistry
No comments:
Post a Comment