Molybdenum disulfide is an inorganic compound composed of molybdenum and sulfur. Its chemical formula is MoS
2.
Nitrogenases are enzymes (EC 1.18.6.1EC 1.19.6.1) that are produced by certain bacteria, such as cyanobacteria (blue-green bacteria) and rhizobacteria. These enzymes are responsible for the reduction of nitrogen (N2) to ammonia (NH3). Nitrogenases are the only family of enzymes known to catalyze this reaction, which is a step in the process of nitrogen fixation. Nitrogen fixation is required for all forms of life, with nitrogen being essential for the biosynthesis of molecules (nucleotides, amino acids) that create plants, animals and other organisms. They are encoded by the Nif genes or homologs. They are related to protochlorophyllide reductase.
In organic chemistry, a carbyne is a general term for any compound whose structure consists of an electrically neutral carbon atom connected by a single covalent bond and has three non-bonded electrons. The carbon atom has either one or three unpaired electrons, depending on its excitation state; making it a radical. The chemical formula can be written R−C· or R−C3·, or just CH.
Molybdenum trioxide describes a family of inorganic compounds with the formula MoO3(H2O)n where n = 0, 1, 2. The anhydrous compound is produced on the largest scale of any molybdenum compound since it is the main intermediate produced when molybdenum ores are purified. The anhydrous oxide is a precursor to molybdenum metal, an important alloying agent. It is also an important industrial catalyst. It is a yellow solid, although impure samples can appear blue or green.
Molybdenum hexacarbonyl (also called molybdenum carbonyl) is the chemical compound with the formula Mo(CO)6. This colorless solid, like its chromium, tungsten, and seaborgium analogues, is noteworthy as a volatile, air-stable derivative of a metal in its zero oxidation state.
Metal aromaticity or metalloaromaticity is the concept of aromaticity, found in many organic compounds, extended to metals and metal-containing compounds. The first experimental evidence for the existence of aromaticity in metals was found in aluminium cluster compounds of the type MAl−
4 where M stands for lithium, sodium or copper. These anions can be generated in a helium gas by laser vaporization of an aluminium / lithium carbonate composite or a copper or sodium / aluminium alloy, separated and selected by mass spectrometry and analyzed by photoelectron spectroscopy. The evidence for aromaticity in these compounds is based on several considerations. Computational chemistry shows that these aluminium clusters consist of a tetranuclear Al2−
4 plane and a counterion at the apex of a square pyramid. The Al2−
4 unit is perfectly planar and is not perturbed by the presence of the counterion or even the presence of two counterions in the neutral compound M
2Al
4. In addition its HOMO is calculated to be a doubly occupied delocalized pi system making it obey Hückel's rule. Finally a match exists between the calculated values and the experimental photoelectron values for the energy required to remove the first 4 valence electrons. The first fully metal aromatic compound was a cyclogallane with a Ga32- core discovered by Gregory Robinson in 1995.
Vanadium tetrachloride is the inorganic compound with the formula VCl4. This reddish-brown liquid serves as a useful reagent for the preparation of other vanadium compounds.
Molybdenum(V) chloride is the inorganic compound with the empirical formula MoCl5. This dark volatile solid is used in research to prepare other molybdenum compounds. It is moisture-sensitive and soluble in chlorinated solvents.
Sulfite oxidase is an enzyme in the mitochondria of all eukaryotes, with exception of the yeasts. It oxidizes sulfite to sulfate and, via cytochrome c, transfers the electrons produced to the electron transport chain, allowing generation of ATP in oxidative phosphorylation. This is the last step in the metabolism of sulfur-containing compounds and the sulfate is excreted.
Trimethylenemethane is a chemical compound with formula C
4H
6. It is a neutral free molecule with two unsatisfied valence bonds, and is therefore a highly reactive free radical. Formally, it can be viewed as an isobutylene molecule C
4H
8 with two hydrogen atoms removed from the terminal methyl groups.
Molybdenum dioxide is the chemical compound with the formula MoO2. It is a violet-colored solid and is a metallic conductor. The mineralogical form of this compound is called tugarinovite, and is only very rarely found. The discovery and early studies of molybdenum dioxide date back to the late 18th and early 19th centuries. One of the notable figures in the history of molybdenum dioxide is the Hungarian chemist Jakob Joseph Winterl (1732–1809). Winterl, who was a professor of chemistry and botany at the University of Budapest, made significant contributions to the understanding of molybdenum compounds. In 1787, he proposed that copper was a compound of nickel, molybdenum, silica, and a volatile substance, showcasing his interest in molybdenum chemistry.
Transition metal dinitrogen complexes are coordination compounds that contain transition metals as ion centers the dinitrogen molecules (N2) as ligands.
A sextuple bond is a type of covalent bond involving 12 bonding electrons and in which the bond order is 6. The only known molecules with true sextuple bonds are the diatomic dimolybdenum (Mo2) and ditungsten (W2), which exist in the gaseous phase and have boiling points of 4,639 °C (8,382 °F) and 5,930 °C (10,710 °F) respectively.
Organomolybdenum chemistry is the chemistry of chemical compounds with Mo-C bonds. The heavier group 6 elements molybdenum and tungsten form organometallic compounds similar to those in organochromium chemistry but higher oxidation states tend to be more common.
Molybdenum(II) acetate is a coordination compound with the formula Mo2(O2CCH3)4. It is a yellow, diamagnetic, air-stable solid that is slightly soluble in organic solvents. Molybdenum(II) acetate is an iconic example of a compound with a metal-metal quadruple bond.
(Mesitylene)molybdenum tricarbonyl is an organomolybdenum compound derived from the aromatic compound mesitylene (1,3,5-trimethylbenzene) and molybdenum carbonyl. It exists as pale yellow crystals, which are soluble in organic solvents but decompose when in solution. It has been examined as a catalyst and reagent.
Molybdenum(V) fluoride is an inorganic compound with the formula MoF5. It is a hygroscopic yellow solid. Like most pentafluorides, it exists as a tetramer.
Transition-metal dichalcogenide (TMD or TMDC) monolayers are atomically thin semiconductors of the type MX2, with M a transition-metal atom (Mo, W, etc.) and X a chalcogen atom (S, Se, or Te). One layer of M atoms is sandwiched between two layers of X atoms. They are part of the large family of so-called 2D materials, named so to emphasize their extraordinary thinness. For example, a MoS2 monolayer is only 6.5 Å thick. The key feature of these materials is the interaction of large atoms in the 2D structure as compared with first-row transition-metal dichalcogenides, e.g., WTe2 exhibits anomalous giant magnetoresistance and superconductivity.
Transition metal nitrile complexes are coordination compounds containing nitrile ligands. Because nitriles are weakly basic, the nitrile ligands in these complexes are often labile.
The epoxidation of allylic alcohols is a class of epoxidation reactions in organic chemistry. One implementation of this reaction is the Sharpless epoxidation. Early work showed that allylic alcohols give facial selectivity when using meta-chloroperoxybenzoic acid (m-CPBA) as an oxidant. This selectivity was reversed when the allylic alcohol was acetylated. This finding leads to the conclusion that hydrogen bonding played a key role in selectivity and the following model was proposed.
