Inorganic chemistry deals with synthesis and behavior of inorganic and organometallic compounds. This field covers chemical compounds that are not carbon-based, which are the subjects of organic chemistry. The distinction between the two disciplines is far from absolute, as there is much overlap in the subdiscipline of organometallic chemistry. It has applications in every aspect of the chemical industry, including catalysis, materials science, pigments, surfactants, coatings, medications, fuels, and agriculture.
Supramolecular chemistry refers to the branch 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. While traditional chemistry concentrates on the covalent bond, supramolecular chemistry examines the weaker and reversible non-covalent interactions between molecules. These forces include hydrogen bonding, metal coordination, hydrophobic forces, van der Waals forces, pi–pi interactions and electrostatic effects.
Adamantane is an organic compound with formula C10H16 or, more descriptively, (CH)4(CH2)6. Adamantane molecules can be described as the fusion of three cyclohexane rings. The molecule is both rigid and virtually stress-free. Adamantane is the most stable isomer of C10H16. The spatial arrangement of carbon atoms in the adamantane molecule is the same as in the diamond crystal. This similarity led to the name adamantane, which is derived from the Greek adamantinos (relating to steel or diamond). It is a white solid with a camphor-like odor. It is the simplest diamondoid.
A polycatenane is a chemical substance that, like polymers, is chemically constituted by a large number of units. These units are made up of concatenated rings into a chain-like structure.
In supramolecular chemistry, host–guest chemistry describes complexes that are composed of two or more molecules or ions that are held together in unique structural relationships by forces other than those of full covalent bonds. Host–guest chemistry encompasses the idea of molecular recognition and interactions through non-covalent bonding. Non-covalent bonding is critical in maintaining the 3D structure of large molecules, such as proteins and is involved in many biological processes in which large molecules bind specifically but transiently to one another.
In chemistry, cryptands are a family of synthetic, bicyclic and polycyclic, multidentate ligands for a variety of cations. The Nobel Prize for Chemistry in 1987 was given to Donald J. Cram, Jean-Marie Lehn, and Charles J. Pedersen for their efforts in discovering and determining uses of cryptands and crown ethers, thus launching the now flourishing field of supramolecular chemistry. The term cryptand implies that this ligand binds substrates in a crypt, interring the guest as in a burial. These molecules are three-dimensional analogues of crown ethers but are more selective and strong as complexes for the guest ions. The resulting complexes are lipophilic.
Endohedral fullerenes, also called endofullerenes, are fullerenes that have additional atoms, ions, or clusters enclosed within their inner spheres. The first lanthanum C60 complex called La@C60 was synthesized in 1985. The @ (at sign) in the name reflects the notion of a small molecule trapped inside a shell. Two types of endohedral complexes exist: endohedral metallofullerenes and non-metal doped fullerenes.
Dynamic covalent chemistry (DCvC) is a synthetic strategy employed by chemists to make complex molecular and supramolecular assemblies from discrete molecular building blocks. DCvC has allowed access to complex assemblies such as covalent organic frameworks, molecular knots, polymers, and novel macrocycles. Not to be confused with dynamic combinatorial chemistry, DCvC concerns only covalent bonding interactions. As such, it only encompasses a subset of supramolecular chemistries.
In supramolecular chemistry, molecular encapsulation is the confinement of a guest molecule inside the cavity of a supramolecular host molecule. Examples of supramolecular host molecule include carcerands and endohedral fullerenes.
In chemistry, a salt bridge is a combination of two non-covalent interactions: hydrogen bonding and ionic bonding. Ion pairing is one of the most important noncovalent forces in chemistry, in biological systems, in different materials and in many applications such as ion pair chromatography. It is a most commonly observed contribution to the stability to the entropically unfavorable folded conformation of proteins. Although non-covalent interactions are known to be relatively weak interactions, small stabilizing interactions can add up to make an important contribution to the overall stability of a conformer. Not only are salt bridges found in proteins, but they can also be found in supramolecular chemistry. The thermodynamics of each are explored through experimental procedures to access the free energy contribution of the salt bridge to the overall free energy of the state.
In chemistry, a resorcinarene is a macrocycle, or a cyclic oligomer, based on the condensation of resorcinol (1,3-dihydroxybenzene) and an aldehyde. Resorcinarenes are a type of calixarene. Other types of resorcinarenes include the related pyrogallolarenes and octahydroxypyridines, derived from pyrogallol and 2,6-dihydroxypyridine, respectively.
Hexamethyldisiloxane (HMDSO or MM) is an organosilicon compound with the formula O[Si(CH3)3]2. This volatile colourless liquid is used as a solvent and as a reagent in organic synthesis. It is prepared by the hydrolysis of trimethylsilyl chloride. The molecule is the protypical disiloxane and resembles a subunit of polydimethylsiloxane.
Physical organic chemistry, a term coined by Louis Hammett in 1940, refers to a discipline of organic chemistry that focuses on the relationship between chemical structures and reactivity, in particular, applying experimental tools of physical chemistry to the study of organic molecules. Specific focal points of study include the rates of organic reactions, the relative chemical stabilities of the starting materials, reactive intermediates, transition states, and products of chemical reactions, and non-covalent aspects of solvation and molecular interactions that influence chemical reactivity. Such studies provide theoretical and practical frameworks to understand how changes in structure in solution or solid-state contexts impact reaction mechanism and rate for each organic reaction of interest.
Jeremy Keith Morris Sanders is a British chemist and Emeritus Professor in the Department of Chemistry at the University of Cambridge. He is also Editor-in-Chief of Royal Society Open Science. He is known for his contributions to many fields including NMR spectroscopy and supramolecular chemistry. He served as the Pro-Vice-Chancellor for Institutional Affairs at the University of Cambridge, 2011–2015.
Cyclotriveratrylene (CTV) is an organic compound with the formula [C6H2(OCH3)2CH2]3. It is a white solid that is soluble in organic solvents. The compound is a macrocycle and used in host–guest chemistry as a molecular host.
Coordination cages are three-dimensional ordered structures in solution that act as hosts in host–guest chemistry. They are self-assembled in solution from organometallic precursors, and often rely solely on noncovalent interactions rather than covalent bonds. Coordinate bonds are useful in such supramolecular self-assembly because of their versatile geometries. However, there is controversy over calling coordinate bonds noncovalent, as they are typically strong bonds and have covalent character. The combination of a coordination cage and a guest is a type of inclusion compound. Coordination complexes can be used as "nano-laboratories" for synthesis, and to isolate interesting intermediates. The inclusion complexes of a guest inside a coordination cage show intriguing chemistry as well; often, the properties of the cage will change depending on the guest. Coordination complexes are molecular moieties, so they are distinct from clathrates and metal-organic frameworks.
Topological inhibitors are rigid three-dimensional molecules of inorganic, organic, and hybrid compounds that form multicentered supramolecular interactions in vacant cavities of protein macromolecules and their complexes.
Supramolecular catalysis refers to an application of supramolecular chemistry, especially molecular recognition and guest binding, toward catalysis. This field was originally inspired by enzymatic system which, unlike classical organic chemistry reactions, utilizes non-covalent interactions such as hydrogen bonding, cation-pi interaction, and hydrophobic forces to dramatically accelerate rate of reaction and/or allow highly selective reactions to occur. Because enzymes are structurally complex and difficult to modify, supramolecular catalysts offer a simpler model for studying factors involved in catalytic efficiency of the enzyme. Another goal that motivates this field is the development of efficient and practical catalysts that may or may not have an enzyme equivalent in nature.
Bromochlorofluoromethane or fluorochlorobromomethane, is a chemical compound and trihalomethane derivative with the chemical formula CHBrClF. As one of the simplest possible stable chiral compounds, it is useful for fundamental research into this area of chemistry. However, its relative instability to hydrolysis, and lack of suitable functional groups, made separation of the enantiomers of bromochlorofluoromethane especially challenging, and this was not accomplished until almost a century after it was first synthesised, in March 2005, though it has now been done by a variety of methods. More recent research using bromochlorofluoromethane has focused on its potential use for experimental measurement of parity violation, a major unsolved problem in quantum physics.
In host–guest chemistry, macromolecular cages are a type of macromolecule structurally consisting of a three-dimensional chamber surrounded by a molecular framework. Macromolecular cage architectures come in various sizes ranging from 1-50 nm and have varying topologies as well as functions. They can be synthesized through covalent bonding or self-assembly through non-covalent interactions. Most macromolecular cages that are formed through self-assembly are sensitive to pH, temperature, and solvent polarity.
