All articles starting with E

Electrophilic amination

Electrophilic amination is a synthetic organic chemistry method forming carbon–nitrogen bonds by transferring an electrophilic amino group to organometallic compounds or enolates, inverting usual amine-synthesis polarity.

Electrophilic aromatic substitution

Electrophilic aromatic substitution is an organic reaction in which an electrophile replaces a hydrogen atom on an aromatic ring such as benzene, most often by halogenation, nitration, sulfonation, or Friedel–Crafts reactions.

Electrophilic fluorination

Electrophilic fluorination is a chemical synthesis method that transfers fluorine to electron-rich sites in organic molecules using reagents such as Selectfluor and NFSI, forming C–F, N–F, or O–F bonds in one step.

Electrophilic halogenation

Electrophilic halogenation is an electrophilic aromatic substitution in which bromine or chlorine replaces hydrogen on an aromatic ring, using a Lewis acid catalyst such as FeBr₃.

Electrophilic substitution

Electrophilic substitution is an organic reaction in which an electrophile replaces a hydrogen on an aromatic ring, installing halogen, nitro, sulfonic acid, alkyl, or acyl groups.

Oct 15, 2026

Electrophilicity index

The electrophilicity index (ω) is a reactivity descriptor from conceptual DFT, defined by Parr, von Szentpály, and Liu in 1999 as electronegativity squared divided by twice chemical hardness.

Electrophoresis

Electrophoresis, also called ionophoresis, is a laboratory technique in which charged molecules such as DNA, RNA, and proteins migrate in an electric field, separating mixtures by size and charge.

Electrophoretic deposition

Electrophoretic deposition, also called electrophoretic painting or electro-coating, deposits charged particles suspended in a liquid onto an electrode under an applied electric field, forming coatings or solid bodies.

Electrophoretic light scattering

Electrophoretic light scattering is an optical characterization technique that measures the electrophoretic mobility of dispersed particles by detecting the Doppler shift of scattered laser light, yielding zeta potential, a standard indicator of colloidal stability.

Electrophoretic mobility shift assay

The electrophoretic mobility shift assay (EMSA), also called the band shift assay, is a gel technique that detects protein–nucleic acid binding, first reported by Garner and Revzin in 1981.

Electrophoretic separation

Electrophoretic separation is a bench technique that moves charged biomolecules such as DNA, RNA, or proteins through a gel under an electric field, sorting them chiefly by size.

Electrophotocatalysis

Electrophotocatalysis, also called electrophotochemistry, is a synthetic method in which a catalyst is activated electrochemically and then photoexcited, so electricity and light jointly drive chemical transformations.

Electrophotocatalysis with cyclopropenium ions

Electrophotocatalysis with cyclopropenium ions is a synthetic method, introduced in 2019, in which anodically oxidized trisaminocyclopropenium ions act as powerful photocatalysts for oxidant-free C–H functionalization.

Electrophysiological mapping

Electrophysiological mapping is a clinical technique recording electrical activity from many points on cardiac or cortical tissue, localizing abnormal conduction paths and seizure foci for treatment planning.

Electrophysiology

Electrophysiology is the study of the electrical properties of biological macromolecules, cells, tissues, and organs, ranging from currents through single ion channels to clinical EEG, ECG, and EMG testing.

Electrophysiology recording

Electrophysiology recording is a laboratory technique that measures the electrical activity of living cells, such as neurons, using electrodes to detect membrane voltage or ionic currents.

Electrophysiology study

Electrophysiology study (EP study, invasive cardiac electrophysiology): catheter-based heart test recording electrical activity to locate arrhythmias, test drugs, map before ablation, and assess sudden cardiac death risk; 1-4 hours, mortality about 0.2%.

Electroplating

Electroplating, also known as electrolytic plating or electrochemical deposition, is an electrodeposition process using electric current to coat a workpiece's cathode with metal, for decoration, corrosion protection, and electronics.

Electropolishing

Electropolishing is an electrochemical finishing method that removes metal from a workpiece anodically, ion by ion, to level, brighten, and passivate it, widely used in the medical, food, pharmaceutical, and semiconductor industries.

Electropolymerization

Electropolymerization is an electrochemical method that forms adherent, usually conducting polymer films on electrodes by oxidizing or reducing dissolved monomers, with thickness set by the charge passed.

Electropop

Electropop: a pop music genre built on synthesizers and drum machines, emerging in the UK in the early 1980s (Human League), influenced by Kraftwerk and Yellow Magic Orchestra, revived in the 2000s by Lady Gaga's The Fame.

Electroporation

Electroporation: pulsed electric fields raise cell membrane permeability via nanoscale pores. Reversible forms deliver drugs and DNA (electrochemotherapy, gene electrotransfer); irreversible electroporation ablates tumors nonthermally.

Electropulsing treatment

Electropulsing treatment is a materials-processing technique in which short pulses of high-density electric current passed through a metal refine grains, relieve stress, and heal fatigue cracks.

Electroreduction

Electroreduction is an electrochemical method that reduces molecules or ions with electrons supplied directly at a cathode, driving organic synthesis, CO2 conversion, and industrial adiponitrile production.

Electroreductive coupling

Electroreductive coupling is a strategy in organic electrosynthesis in which carbon-carbon or carbon-heteroatom bonds form under cathodic electrolysis, with electric current replacing stoichiometric reductants such as zinc or manganese powders.

Electroreductive cross-coupling of alkyl halides

Electroreductive cross-coupling of alkyl halides, often called electroreductive cross-electrophile coupling or eXEC, forms carbon–carbon bonds between two electrophiles using electrons from a cathode in place of zinc or manganese.

Electroreductive deoxygenation

Electroreductive deoxygenation is a family of organic electrosynthesis reactions that remove or convert oxygen groups, chiefly C–O and C=O bonds, at a cathode using electrons as the reductant.

Electroretinography

Electroretinography (ERG) is a non-invasive diagnostic test that records the retina's summed electrical response to light, with waveform components localizing dysfunction from photoreceptors to ganglion cells.

Oct 15, 2026

Electrorheological fluid

An electrorheological (ER) fluid is a suspension of polarizable particles in insulating liquid that turns solid-like within milliseconds under an electric field, an effect patented by Willis Winslow in 1947.