Complex conjugateIn mathematics, the complex conjugate of a complex number is the number with an equal real part and an imaginary part equal in magnitude but opposite in sign. That is, if and are real numbers then the complex conjugate of is The complex conjugate of is often denoted as or . In polar form, if and are real numbers then the conjugate of is This can be shown using Euler's formula. The product of a complex number and its conjugate is a real number: (or in polar coordinates).
Aldol condensationAn aldol condensation is a condensation reaction in organic chemistry in which two carbonyl moieties (of aldehydes or ketones) react to form a β-hydroxyaldehyde or β-hydroxyketone (an aldol reaction), and this is then followed by dehydration to give a conjugated enone. The overall reaction equation is as follows (where the Rs can be H) Aldol condensations are important in organic synthesis and biochemistry as ways to form carbon–carbon bonds.
Inductive effectIn chemistry, the inductive effect in a molecule is a local change in the electron density due to electron-withdrawing or electron-donating groups elsewhere in the molecule, resulting in a permanent dipole in a bond. It is present in a σ (sigma) bond, unlike the electromeric effect which is present in a π (pi) bond. The halogen atoms in an alkyl halide are electron withdrawing while the alkyl groups have electron donating tendencies.
Ceramic metal-halide lampA ceramic metal-halide lamp (CMH), also generically known as a ceramic discharge metal-halide (CDM) lamp, is a type of metal-halide lamp that is 10–20% more efficient than the traditional quartz metal halide and produces a superior color rendition (80-96 CRI). Applications for these lamps include shop lighting, street lighting, architectural lighting and agricultural lighting including grow lights. A CMH light was first exhibited by the Thorn Lighting Group in 1981 at the Hannover World Light Fair, and the first commercial ceramic metal halide lamps were distributed by Philips in 1994.
DiazoIn organic chemistry, the diazo group is an organic moiety consisting of two linked nitrogen atoms (azo, ) at the terminal position. Overall charge-neutral organic compounds containing the diazo group bound to a carbon atom are called diazo compounds or diazoalkanes and are described by the general structural formula . The simplest example of a diazo compound is diazomethane, . Diazo compounds () should not be confused with azo compounds () or with diazonium compounds ().
Organomolybdenum chemistryOrganomolybdenum 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 hexacarbonyl is the precursor to many substituted derivatives. It reacts with organolithium reagents to give anionic acyls which can be O-alkylated to give Fischer carbenes. Mo(CO)6 reacts with arenes to give piano-stool complexes such as (mesitylene)molybdenum tricarbonyl.
PhytochemistryPhytochemistry is the study of phytochemicals, which are chemicals derived from plants. Phytochemists strive to describe the structures of the large number of secondary metabolites found in plants, the functions of these compounds in human and plant biology, and the biosynthesis of these compounds. Plants synthesize phytochemicals for many reasons, including to protect themselves against insect attacks and plant diseases. The compounds found in plants are of many kinds, but most can be grouped into four major biosynthetic classes: alkaloids, phenylpropanoids, polyketides, and terpenoids.
Claisen rearrangementThe Claisen rearrangement is a powerful carbon–carbon bond-forming chemical reaction discovered by Rainer Ludwig Claisen. The heating of an allyl vinyl ether will initiate a [3,3]-sigmatropic rearrangement to give a γ,δ-unsaturated carbonyl, driven by exergonically favored carbonyl CO bond formation (ΔΔHf = -327 kcal·mol−1). The Claisen rearrangement is an exothermic, concerted (bond cleavage and recombination) pericyclic reaction. Woodward–Hoffmann rules show a suprafacial, stereospecific reaction pathway.
