Alkynes characteristically undergo reactions that show that they are " doubly unsaturated ," meaning that each alkyne unit is capable of adding two equivalents of H < sub > 2 </ sub >, halogens or related HX reagents ( X = halide, pseudohalide, etc .).

Alkynes are traditionally known as acetylenes, although the name acetylene also refers specifically to C < sub > 2 </ sub > H < sub > 2 </ sub >, known formally as ethyne using IUPAC nomenclature.

Alkynes are characteristically more unsaturated than alkenes.

Alkynes are usually more reactive than alkenes.

Alkynes can be prepared from aldehydes using the Corey-Fuchs reaction and from aldehydes or ketones by the Seyferth – Gilbert homologation.

Alkynes occur in some pharmaceuticals, including the contraceptive norethynodrel.

Alkynes react similarly, forming the tetrahalo compounds.

SBS block copolymer in Transmission electron microscopy | TEM Copolymers can undergo microphase separation to form a diverse array of periodic nanostructures, as shown in the example of the styrene-butadiene-styrene block copolymer shown at right.

In fact, he argues, artifacts and sites undergo, respectively post-use and post-occupational modification by diverse formation processes.

Non-carbon reagents also undergo cyclization, e. g. Azide alkyne Huisgen cycloaddition to give triazoles.

They will also undergo cycloaddition reactions with electron-rich alkynes to form cyclobutenones, or carbonyl groups to form beta-lactones.

# They undergo electrophilic substitution reactions and nucleophilic aromatic substitutions.

Amides undergo many chemical reactions, usually through an attack on the carbonyl breaking the carbonyl double bond and forming a tetrahedral intermediate.

Analogous to the above reactions, the glucose produced can then undergo glycolysis in tissues that need energy, be stored as glycogen ( or starch in plants ), or be converted to other monosaccharides or joined into di-or oligosaccharides.

The type of chemical reactions a substance may undergo and the energy changes that may accompany it are constrained by certain basic rules, known as chemical laws.

A molecule is the smallest indivisible portion of a pure chemical substance that has its unique set of chemical properties, that is, its potential to undergo a certain set of chemical reactions with other substances.

Solid and heavy liquid fuels also undergo a great number of pyrolysis reactions that give more easily oxidized, gaseous fuels.

The acidity of the α-hydrogen also allows ketones and other carbonyl compounds to undergo nucleophilic reactions at that position, with either stoichiometric and catalytic base.

Similarly, methyl iodide and methyl triflate are viewed as the equivalent of the methyl cation because they readily undergo S < sub > N </ sub > 2 reactions by weak nucleophiles.

Nucleotides undergo breakdown such that useful parts can be reused in synthesis reactions to create new nucleotides.

It is impossible for a nuclear power plant to undergo a nuclear chain reaction that results in an explosion of power comparable with a nuclear weapon, but even low-powered explosions due to uncontrolled chain reactions, that would be considered " fizzles " in a bomb, may still cause considerable damage and meltdown in a reactor.

While pure hydrocarbons undergo certain limited classes of reactions, many more reactions which organic compounds undergo are largely determined by functional groups.

Organometallic compounds with bonds that have characters in between ionic and covalent are very important in industry, as they are both relatively stable in solutions and relatively ionic to undergo reactions.

Organometallic compounds undergo several important reactions:

Metal ion cofactors undergo redox reactions without binding or releasing protons, so in the electron transport chain they serve solely to transport electrons through proteins.

Nevertheless, peptide bonds can undergo chemical reactions, usually through an attack of an electronegative atom on the carbonyl carbon, breaking the carbonyl double bond and forming a tetrahedral intermediate.

Typical precursors are metal alkoxides and metal chlorides, which undergo various forms of hydrolysis and polycondensation reactions in order to form a viscoelastic network ( or solid ).

In cold fusion reactions, the produced fused nuclei have a relatively low excitation energy (~ 10 – 20 MeV ), which decreases the probability that these products will undergo fission reactions.

Necrotic tissue does not undergo the same chemical reactions that normally dying apoptotic tissue does.

Instead of giving themselves spontaneously to the orgiastic release that jazz can give them, they undergo psychoanalysis or flirt with mysticism or turn to prostitutes for satisfaction.

First of all, the recruits will have to undergo arduous schooling.

but, as a second-look safeguard, each new project must undergo a Board of Estimate public hearing before construction proceeds.

This unusual collagen also was shown to undergo a reversible thermal phase transformation.

-- Glycerinated muscle, in the presence of the physiological agent ( ATP ) responsible for delivering energy to the mechanochemically active proteins of muscle, has been shown to undergo a contraction which is highly sensitive both to temperature and to solvent composition in mixtures of alcohols and water.

At this moment, all he could think of was what he'd been forced to undergo.

-- Bobby Waters of Sylvania, Ga., relief quarterback for the San Francisco 49ers of the National Football League, will undergo a knee operation tomorrow at Franklin Hospital here.

`` You see '', she said, looking past him into the room, where the highball glasses sparkled dully in the bright light, `` you and I can't understand the many hardships they have to undergo ''.

The young undergo metamorphosis from a larval form with gills to an adult air-breathing form with lungs.

Most amphibians lay their eggs in water and have aquatic larvae that undergo metamorphosis to become terrestrial adults.

Others brood their eggs and the larvae undergo metamorphosis before the eggs hatch.

Sometimes, countries have the written language undergo a spelling reform to realign the writing with the contemporary spoken language.

After Alex's fellow cellmates blame him for beating a troublesome cellmate to death, he agrees to undergo an experimental behaviour-modification treatment called the Ludovico Technique.

Each element has at least one isotope with an unstable nucleus that can undergo radioactive decay.

Electrons that are bound to atoms possess a set of stable energy levels, or orbitals, and can undergo transitions between them by absorbing or emitting photons that match the energy differences between the levels.

Professionally, an architect's decisions affect public safety, and thus an architect must undergo specialized training consisting of advanced education and a practicum ( or internship ) for practical experience to earn a license to practice architecture.

In the Catholic church, all who die in god's grace and friendship, but still imperfectly purified, are indeed assured of their eternal salvation ; but after death they undergo purification, so as to achieve the holiness necessary to enter the joy of heaven or the final purification of the elect, which is entirely different from the punishment of the damned.

Unlike other Christian groups, the Catholic Church teaches that those who die in a state of grace, but still carry venial sin go to a place called Purgatory where they undergo purification to enter Heaven.

After a statistically sufficient quantity of time, an electron in an excited state will undergo a transition to a lower state.

" The black race of Africa are inferior to the white man in point of intellect – better calculated in physical structure to undergo drudgery and hardship – standing, as they do, many degrees lower in the scale of gradation that expresses the relative relation between God and all that he has created than the white man.

While encysted it may undergo a peculiar process of autogamy or self-fertilization, where it goes through meiosis and divides to form two gametes, which then fuse together again.

Both of these elastomers undergo strain crystallization.

Dying cells that undergo the final stages of apoptosis display phagocytotic molecules, such as phosphatidylserine, on their cell surface.