In organic chemistry, ethers are a class of compounds that contain an ether group—an oxygen atom connected to two organyl groups. They have the general formula R−O−R′, where R and R′ represent organyl groups. Ethers can again be classified into two varieties: if the organyl groups are the same on both sides of the oxygen atom, then it is a simple or symmetrical ether, whereas if they are different, the ethers are called mixed or unsymmetrical ethers. A typical example of the first group is the solvent and anaesthetic diethyl ether, commonly referred to simply as "ether". Ethers are common in organic chemistry and even more prevalent in biochemistry, as they are common linkages in carbohydrates and lignin.
An explosive is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An explosive charge is a measured quantity of explosive material, which may either be composed solely of one ingredient or be a mixture containing at least two substances.
In organic chemistry, a functional group is a substituent or moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions regardless of the rest of the molecule's composition. This enables systematic prediction of chemical reactions and behavior of chemical compounds and the design of chemical synthesis. The reactivity of a functional group can be modified by other functional groups nearby. Functional group interconversion can be used in retrosynthetic analysis to plan organic synthesis.
Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms. Study of structure determines their structural formula. Study of properties includes physical and chemical properties, and evaluation of chemical reactivity to understand their behavior. The study of organic reactions includes the chemical synthesis of natural products, drugs, and polymers, and study of individual organic molecules in the laboratory and via theoretical study.
An oxymoron is a figure of speech that juxtaposes concepts with opposite meanings within a word or in a phrase that is a self-contradiction. As a rhetorical device, an oxymoron illustrates a point to communicate and reveal a paradox. A general meaning of "contradiction in terms" is recorded by the 1902 edition of the Oxford English Dictionary.
In grammar, a part of speech or part-of-speech is a category of words that have similar grammatical properties. Words that are assigned to the same part of speech generally display similar syntactic behavior, sometimes similar morphological behavior in that they undergo inflection for similar properties and even similar semantic behavior. Commonly listed English parts of speech are noun, verb, adjective, adverb, pronoun, preposition, conjunction, interjection, numeral, article, and determiner.
In organic chemistry, aromaticity is a chemical property describing the way in which a conjugated ring of unsaturated bonds, lone pairs, or empty orbitals exhibits a stabilization stronger than would be expected by the stabilization of conjugation alone. The earliest use of the term was in an article by August Wilhelm Hofmann in 1855. There is no general relationship between aromaticity as a chemical property and the olfactory properties of such compounds.
Volatility or volatile may refer to:
Empathogens or entactogens are a class of psychoactive drugs that induce the production of experiences of emotional communion, oneness, relatedness, emotional openness—that is, empathy or sympathy—as particularly observed and reported for experiences with 3,4-methylenedioxymethamphetamine (MDMA). This class of drug is distinguished from the classes of hallucinogen or psychedelic, and amphetamine or stimulants. Major members of this class include MDMA, MDA, MDEA, MDOH, MBDB, 5-APB, 5-MAPB, 6-APB, 6-MAPB, methylone, mephedrone, GHB, αMT, and αET, MDAI among others. Most entactogens are phenethylamines and amphetamines, although several, such as αMT and αET, are tryptamines. When referring to MDMA and its counterparts, the term MDxx is often used. Entactogens are sometimes incorrectly referred to as hallucinogens or stimulants, although many entactogens such as ecstasy exhibit psychedelic or stimulant properties as well.
Vitriol is the general chemical name encompassing a class of chemical compounds comprising sulfates of certain metals – originally, iron or copper. Those mineral substances were distinguished by their color, such as green vitriol for hydrated iron(II) sulfate and blue vitriol for hydrated copper(II) sulfate.
Fluorouracil, sold under the brand name Adrucil among others, is a cytotoxic chemotherapy medication used to treat cancer. By intravenous injection it is used for treatment of colorectal cancer, oesophageal cancer, stomach cancer, pancreatic cancer, breast cancer, and cervical cancer. As a cream it is used for actinic keratosis, basal cell carcinoma, and skin warts.
Capecitabine, sold under the brand name Xeloda among others, is a anticancer medication used to treat breast cancer, gastric cancer and colorectal cancer. For breast cancer it is often used together with docetaxel. It is taken by mouth.
A class in education has a variety of related meanings.
In chemistry, phosphorus oxoacid is a generic name for any acid whose molecule consists of atoms of phosphorus, oxygen, and hydrogen. There is a potentially infinite number of such compounds. Some of them are unstable and have not been isolated, but the derived anions and organic groups are present in stable salts and esters. The most important ones—in biology, geology, industry, and chemical research—are the phosphoric acids, whose esters and salts are the phosphates.
A chemical nomenclature is a set of rules to generate systematic names for chemical compounds. The nomenclature used most frequently worldwide is the one created and developed by the International Union of Pure and Applied Chemistry (IUPAC).
A cyclic compound is a term for a compound in the field of chemistry in which one or more series of atoms in the compound is connected to form a ring. Rings may vary in size from three to many atoms, and include examples where all the atoms are carbon, none of the atoms are carbon, or where both carbon and non-carbon atoms are present. Depending on the ring size, the bond order of the individual links between ring atoms, and their arrangements within the rings, carbocyclic and heterocyclic compounds may be aromatic or non-aromatic; in the latter case, they may vary from being fully saturated to having varying numbers of multiple bonds between the ring atoms. Because of the tremendous diversity allowed, in combination, by the valences of common atoms and their ability to form rings, the number of possible cyclic structures, even of small size numbers in the many billions.
In chemical nomenclature, a preferred IUPAC name (PIN) is a unique name, assigned to a chemical substance and preferred among all possible names generated by IUPAC nomenclature. The "preferred IUPAC nomenclature" provides a set of rules for choosing between multiple possibilities in situations where it is important to decide on a unique name. It is intended for use in legal and regulatory situations.
Tegafur is a chemotherapeutic prodrug of 5-fluorouracil (5-FU) used in the treatment of cancers. It is a component of the combination drug tegafur/uracil. When metabolised, it becomes 5-FU.
These drugs are known in the UK as controlled drug, because this is the term by which the act itself refers to them. In more general terms, however, many of these drugs are also controlled by the Medicines Act 1968, there are many other drugs which are controlled by the Medicines Act but not by the Misuse of Drugs Act, and some other drugs are controlled by other laws.
Secretary is a title often used in organizations to indicate a person having a certain amount of authority, power, or importance in the organization. Secretaries announce important events and communicate to the organization. The term is derived from the Latin word secernere, "to distinguish" or "to set apart", the passive participle meaning "having been set apart", with the eventual connotation of something private or confidential, as with the English word secret. A secretarius was a person, therefore, overseeing business confidentially, usually for a powerful individual.
