Alphabetical Index

Additional Indexes

Physical Constants Units of Measure Physical Quantities SI Prefixes Ring Index General Formulae Exact Formulae Source Documents Terms by IUPAC Div.

Version 3.0.1 (6463 Terms)

DOI: 10.1351/goldbook

Jan Kaiser - Content Editor
Stuart Chalk - Technical Editor
Joint Subcommittee
on the IUPAC Gold Book

Terms sourced from: 10.1351/pac199466051077

"Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)", Muller, P., Pure and Applied Chemistry 1994, 66(5), 1077

α-addition α-effect α-elimination 'A' value abstraction acceptor number \(\text{AN}\)acid acidity function activated complex activation energy addend addition reaction additivity principle adduct agostic allylic substitution reaction alternant ambident amphiphilic amphiprotic (solvent) amphoteric anionotropic rearrangement annelation annulation annulenes antarafacial anti-Hammond effect aprotic (solvent) aquation Arrhenius equation aryne association asymmetric induction atomic orbital \(\psi\),\(\varphi\),\(\chi\)attachment autocatalytic reaction automerization autoprotolysis autoprotolysis constant azacarbenes azenes azylenes π-adduct σ-adduct A-factor \(A\)alcoholysis anchimeric assistance anion radical anti-Markownikoff addition acidity addition anti arenium ions aromatic

Baldwin's rules base basicity bathochromic shift (effect) Bell–Evans–Polanyi principle benzynes bifunctional catalysis binding site biradical Bodenstein approximation bond bond dissociation bond energy bond number bond order \(p_{\text{rs}}\)bond-dissociation energy \(D\)borderline mechanism Bredt's rule bridged carbocation bridging ligand Brønsted acid Brønsted base Brønsted relation Bunnett–Olsen equations π-bond σ-bond basicity function bimolecular bond migration

cage cage compound captodative effect carbanion carbenes carbenium centre carbenium ion carbenoids carbocation carbynes catalysis catalyst catalytic coefficient cationotropic rearrangement cationotropy chain reaction chain transfer chain-termination reaction charge population charge-transfer complex chelate chelation cheletropic reaction chelotropic reaction chemical decomposition chemical equilibrium chemical flux \(\varphi\)chemical reaction chemical relaxation chemical species chemiflux chemoselectivity (chemoselective) chemospecificity chromophore Chemically Induced Dynamic Nuclear Polarization cine-substitution class (a) metal ion class (b) metal ion clathrates colligation common-ion effect (on rates) compensation effect complementary binding sites complex composite reaction comproportionation concerted process condensation reaction configuration (electronic) configuration (stereochemical) conformation conjugate acid–base pair conjugated system conjugative mechanism connectivity constitution contributing structure coordinate covalence coordinate link coordination coordination number coordinatively saturated complex coordinatively unsaturated complex coronands correlation analysis coupling constant (spin-spin) \(J\)covalent bond Cox–Yates equation critical micelle concentration cross-conjugation crown cryptand Curtin–Hammett principle cybotactic region cyclization cycloaddition cycloelimination σ-constant canonical form catalysis law chemically induced dynamic nuclear polarization conjugation contact ion pair cryptate cycloreversion carbonium ion

de-electronation degenerate rearrangement delocalization detachment detailed balancing (principle of) diamagnetic diastereoisomerism dielectric constant dienophile dimerization Dimroth–Reichardt E_T parameter dipolar aprotic solvent dipolar bond dipole-induced dipole forces dipole–dipole interaction disproportionation dissociation distonic radical cation donor number (DN) downfield driving force (affinity) of a reaction \(A\)dual substituent-parameter equation dyotropic rearrangement dipolar cycloaddition dismutation dispersion forces disrotatory

educt effective charge effective molarity eighteen-electron rule electrocyclic reaction electrofuge electromeric effect electron acceptor electron affinity \(E_{\text{ea}}\)electron attachment electron density electron detachment electron transfer electron-deficient bond electron-donor-acceptor complex electron-pair acceptor electron-pair donor electron-transfer catalysis electronation electronegativity electroneutrality principle electronic effect of substituents: symbols and signs electrophile element effect elementary reaction elimination enantiomer enantioselectivity encounter complex encounter pair encounter-controlled rate ene reaction energy of activation energy profile enforced concerted mechanism entering group enthalpy of activation \(\Delta ^{\ddagger}H^{\,\unicode{x26ac}}\)entropy of activation \(\Delta ^{\ddagger}S^{\,\unicode{x26ac}}\)epimerization epimers ET-value \(E_{\text{T}}\)excess acidity excimer exciplex excited state extended Hammett equation external ion return external return extrusion transformation π-electron acceptor/donor group ρσ-equation enophile equilibrium control equilibrium isotope effect external ion-pair return electrophilicity electron donor

fast-atom bombardment (FAB) mass spectroscopy field effect flash vacuum pyrolysis fluxional free radical frontier orbitals functional group fragmentation

gas-phase acidity gas-phase basicity geminate pair geminate recombination general acid catalysis general base catalysis Gibbs energy diagram Gibbs energy of activation \(\Delta ^{\ddagger}G^{\,\unicode{x26ac}}\)Gibbs energy profile ground state group group electronegativity Grunwald–Winstein equation guest

η (eta or hapto) half life \(t_{1/2}\)halochromism Hammett equation Hammond principle Hansch constant hard acid hard base heat capacity of activation \(\Delta ^{\ddagger}C_{p}^{\,\unicode{x26ac}}\)heavy atom isotope effect hemileptic Henderson–Hasselbalch equation heterobimetallic complex heteroleptic heterolysis heterolytic bond-dissociation energy Hildebrand parameter Hofmann rule homo homoaromatic homoleptic homolysis host Hückel (4n + 2) rule hybridization hydration hydrogen bond hydrolysis hydron hydrophilic hydrophobic interaction hyperconjugation hypsochromic shift heterovalent hyperconjugation hidden return homoconjugation heteroconjugation

identity reaction imbalance imenes imin imine radical inclusion compound induction period inductive effect inductomeric effect inert inhibition initiation inner-sphere electron transfer insertion intermediate intramolecular catalysis intramolecular isotope effect intrinsic barrier inverse isotope effect inverse kinetic isotope effect inverted micelle ion pair ion pair return ionization ionization energy \(E_{\text{i}}\)ionizing power ipso-attack isodesmic reaction isoelectronic isoentropic isoequilibrium relationship isokinetic relationship isolobal isomer isomerization isoselective relationship isotope effect isotope exchange isotopic fractionation factor isotopic scrambling isotopologue isotopomer intermolecular intramolecular

Kamlet–Taft solvent parameters Kekulé structure (for aromatic compounds) kinetic ambiguity kinetic control kinetic electrolyte effect kinetic equivalence kinetic isotope effect Koppel–Palm solvent parameters Kosower Z-value

labile leaving group left-to-right convention levelling effect Lewis acid Lewis acidity Lewis adduct Lewis base Lewis basicity Lewis formula (electron dot or Lewis structure) ligands line formula line-shape analysis linear free-energy relation linear solvation energy relationships lipophilic lipophilicity London forces lone (electron) pair lyate ion lyonium ion

magnetic equivalence magnetization transfer Markownikoff rule mass-law effect matrix isolation mean life \(\tau\)mechanism mechanism-based inhibition medium Meisenheimer adduct melting point (corrected/uncorrected) mesolytic cleavage mesomeric effect mesomerism metastable metathesis method of isotopic perturbation methylene methylidyne micellar catalysis micelle Michaelis–Menten kinetics microscopic chemical event microscopic diffusion control migratory aptitude migratory insertion mixing control Möbius aromaticity moiety molecular entity molecular mechanics calculation molecular metal molecular orbital molecular rearrangement molecularity molecule More O'Ferrall–Jencks diagram multi-centre bond multi-centre reaction migration

n-σ* delocalization narcissistic reaction neighbouring group participation NIH shift nitrenium ions no-bond resonance nonclassical carbocation normal kinetic isotope effect nucleofuge nucleophile nucleophilic catalysis nitrenes nucleophilicity

opposing reactions optical yield orbital steering orbital symmetry order of reaction \(n\)outer-sphere electron transfer oxidative addition oxidative coupling σ-orbital onium compounds oxidation

π-complex parallel reactions paramagnetic partial rate factor pericyclic reaction periselectivity perpendicular effect persistent pH-rate profile phase-transfer catalysis photolysis polar aprotic solvent polar effect polar solvent polarity polarizability potential-energy profile potential-energy (reaction) surface pre-association pre-equilibrium (prior equilibrium) primary isotope effect primary kinetic isotope effect primitive change principle of least nuclear motion principle of microscopic reversibility product development control product-determining step promotion propagation protic protolysis proton affinity proton transfer reaction protophilic (solvent) prototropic rearrangement pseudo-catalysis pseudo-first-order reaction pseudo-unimolecular pseudo-zero-order reaction pseudomolecular rearrangement pseudopericyclic

quantitative structure–activity relationships

radical centre(s) radical combination radical (free radical) radical ion radical pair radiolysis rate coefficient rate law rate of disappearance rate of reaction \(\nu\)rate-controlling step rate-determining step reaction reaction coordinate reaction intermediate reaction stage reaction step reactive (reactivity) reactivity index reactivity–selectivity principle rearrangement rearrangement stage reduction reductive elimination regioselectivity (regioselective) relaxation relaxation kinetics resonance resonance energy retroaddition retrocycloaddition Ritchie equation reacting bond rules reaction path

σ, π (sigma, pi) salt effect saturation transfer Saytzeff rule scavenger scrambling secondary isotope effect secondary kinetic isotope effect selectivity selectivity factor \(S_{f}\)selectivity shielding sigmatropic rearrangement single-electron transfer mechanism single-step reaction Slater-type orbital solvation solvatochromic relationship solvatochromism solvent isotope effect solvent parameter solvolysis solvophobicity parameter \(Sp\)SOMO sonication special salt effect specific catalysis spectator mechanism spin density spin label spin trapping stable stepwise reaction stereoelectronic stereoelectronic control stereoselectivity steric effect steric hindrance steric isotope effect steric strain steric-approach control stopped flow strain subjacent orbital substituent atom (group) substituent electronegativity substitution reaction substrate successor complex superacid supramolecule Swain–Lupton equation Swain–Scott equation symbiosis symproportionation synchronization (principle of nonperfect synchronization) synchronous silylene stationary state steady state stereospecificity

Taft equation tautomeric effect tautomerism tautomerization tele-substitution telomerization termination tetrahedral intermediate thermodynamic control thermodynamic isotope effect thermolysis torquoselectivity total chemiflux transferability transformation transient (chemical) species transition state transition state analogue transition structure transmission coefficient transport control trapping tunnelling transition coordinate

umpolung unreactive unstable upfield

ρ-value valence valence isomer valence tautomerization van der Waals forces volume of activation \(\Delta ^{\ddagger}V\)

Wheland intermediate Woodward–Hoffmann rules

ylides Yukawa–Tsuno equation

Z-value Zucker–Hammett hypothesis zwitterionic compounds/zwitterions