Porphyrins are a group of heterocyclic macrocycle organic compounds, composed of four modified pyrrole subunits interconnected at their α carbon atoms via methine bridges (=CH−). In vertebrates, an essential member of the porphyrin group is heme, which is a component of hemoproteins, whose functions include carrying oxygen in the bloodstream. In plants, an essential porphyrin derivative is chlorophyll, which is involved in light harvesting and electron transfer in photosynthesis.
In macromolecular chemistry, a catenane is a mechanically interlocked molecular architecture consisting of two or more interlocked macrocycles, i.e. a molecule containing two or more intertwined rings. The interlocked rings cannot be separated without breaking the covalent bonds of the macrocycles. They are conceptually related to other mechanically interlocked molecular architectures, such as rotaxanes, molecular knots or molecular Borromean rings. Recently the terminology "mechanical bond" has been coined that describes the connection between the macrocycles of a catenane. Catenanes have been synthesised in two different ways: statistical synthesis and template-directed synthesis.
1,10-Phenanthroline (phen) is a heterocyclic organic compound. It is a white solid that is soluble in organic solvents. The 1,10 refer to the location of the nitrogen atoms that replace CH's in the hydrocarbon called phenanthrene.
Macrocycles are often described as molecules and ions containing a ring of twelve or more atoms. Classical examples include the crown ethers, calixarenes, porphyrins, and cyclodextrins. Macrocycles describe a large, mature area of chemistry.
1,4,7-Triazacyclononane, known as "TACN" which is pronounced "tack-en," is an aza-crown ether with the formula (C2H4NH)3. TACN is derived, formally speaking, from cyclononane by replacing three equidistant CH2 groups with NH groups. TACN is one of the oligomers derived from aziridine, C2H4NH. Other members of the series include piperazine, C4H8(NH)2, and the cyclic tetramer 1,4,7,10-tetraazacyclododecane.
In organic chemistry, an aza-crown ether is an aza analogue of a crown ether. That is, it has a nitrogen atom in place of each oxygen atom around the ring. While the parent crown ethers have the formulae (CH2CH2O)n, the parent aza-crown ethers have the formulae (CH2CH2NH)n, where n = 3, 4, 5, 6. Well-studied aza crowns include triazacyclononane, cyclen, and hexaaza-18-crown-6.
Vanadium(V) oxytrifluoride is a chemical compound with the formula VOF3. It is one of several vanadium(V) oxyhalides. VOF3 is a yellowish orange powder that is sensitive to moisture. Characteristic of early metal fluorides, the structure is polymeric in the solid state. The solid adopts a layered structure but upon evaporation, the species becomes dimeric. In contrast VOCl3 and VOBr3 remain tetrahedral in all states, being volatile liquids at room temperature.
Trimethyl phosphite is an organophosphorus compound with the formula P(OCH3)3, often abbreviated P(OMe)3. It is a colorless liquid with a highly pungent odor. It is the simplest phosphite ester and finds used as a ligand in organometallic chemistry and as a reagent in organic synthesis. The molecule features a pyramidal phosphorus(III) center bound to three methoxy groups.
In chemistry, a template reaction is any of a class of ligand-based reactions that occur between two or more adjacent coordination sites on a metal center. In the absence of the metal ion, the same organic reactants produce different products. The term is mainly used in coordination chemistry. Thetemplate effects emphasizes the pre-organization provided by the coordination sphere, although the coordination modifies the electronic properties of ligands.
Organosilver chemistry is the study of organometallic compounds containing a carbon to silver chemical bond. The theme is less developed than organocopper chemistry.
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.
In coordination chemistry, a macrocyclic ligand is a macrocyclic ring having at least nine atoms and three or more donor sites that serve as ligands that can bind to a central metal ion. Crown ethers and porphyrins are prominent examples. Macrocyclic ligands exhibit high affinity for metal ions.
Karl Wieghardt is a German inorganic chemist and emeritus director of the Max Planck Institute for Chemical Energy Conversion in Mülheim. He was active in the preparation and detailed characterization of models for iron and manganese metalloenzymes, metal complexes of noninnocent ligands, and magnetic interactions in polynuclear metal complexes.
Bispidine (3,7-diazabicyclo[3.3.1]nonane) is an organic compound that is classified as a bicyclic diamine. Although synthetic, it is related structurally to natural alkaloid sparteine. It is a white crystalline solid. It has been widely investigated as a chelating agent. Many derivatives are known.
Transition metal pyridine complexes encompass many coordination complexes that contain pyridine as a ligand. Most examples are mixed-ligand complexes. Many variants of pyridine are also known to coordinate to metal ions, such as the methylpyridines, quinolines, and more complex rings.
Gillian Reid is a British chemist who is Professor of Inorganic Chemistry and former Head of the Department of Chemistry at the University of Southampton. Her research considers coordination chemistry, inorganic semiconductors and metal fluoride scaffolds. In 2020, she was appointed the President-elect of the Royal Society of Chemistry, becoming President in 2022.
Transition metal thioether complexes comprise coordination complexes of thioether (R2S) ligands. The inventory is extensive.
In organic chemistry, thia-crown ethers are organosulfur compounds which are the thia analogues of crown ethers. That is, they have a sulfur atom in place of each oxygen atom around the ring. While the parent crown ethers have the formulae (CH2CH2O)n, the parent thia-crown ethers have the formulae (CH2CH2S)n, where n = 3, 4, 5, 6. They have trivial names "x-ane-Sy", where x and y are the number of atoms in the ring and the number of those atoms that are sulfur, respectively. Thia-crown ethers exhibit affinities for transition metals.
A transition metal sulfoxide complex is a coordination complex containing one or more sulfoxide ligands. The inventory is large.
Vanadium dioxide fluoride is the inorganic compound with the formula VO2F. It is an orange diamagnetic solid. The compound adopts the same structure as iron(III) fluoride, with octahedral metal centers and doubly bridging oxide and fluoride ligands. It is prepared by the reaction of vanadium pentoxide and vanadium(V) oxytrifluoride:
