06218 IUPAC Gold Book - synchronization 10.1351/goldbook.S06218 S06218 current related: principle of nonperfect synchronization 1 This principle applies to reactions in which there is a lack of synchronization between bond formation or bond rupture and other primitive changes that affect the stability of products and reactants, such as resonance, solvation, electrostatic, hydrogen bonding and polarizability effects. The principle states that a product-stabilizing factor whose development lags behind bond changes at the transition state, or a reactant-stabilizing factor whose loss is ahead of bond changes at the transition state, increases the intrinsic barrier and decreases the 'intrinsic rate constant' of a reaction. For a product-stabilizing factor whose development is ahead of bond changes, or reactant factors whose loss lags behind bond changes, the opposite relations hold. The reverse effects are observable for factors that destabilize a reactant or product. hydrogen bonding https://goldbook.iupac.org/terms/view/H02899 imbalance https://goldbook.iupac.org/terms/view/I02945 intrinsic barrier https://goldbook.iupac.org/terms/view/I03135 polarizability https://goldbook.iupac.org/terms/view/P04711 primitive changes https://goldbook.iupac.org/terms/view/P04845 rate constant https://goldbook.iupac.org/terms/view/O04322 resonance https://goldbook.iupac.org/terms/view/R05326 solvation https://goldbook.iupac.org/terms/view/S05747 synchronous https://goldbook.iupac.org/terms/view/S06219 transition state https://goldbook.iupac.org/terms/view/T06468 PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1170 (https://doi.org/10.1351/pac199466051077) https://goldbook.iupac.org/terms/view/S06218/html https://goldbook.iupac.org/terms/view/S06218/json https://goldbook.iupac.org/terms/view/S06218/plain Citation: 'synchronization' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.S06218 The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms. If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org . The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using. 2026-05-10T11:05:00+00:00