{"term":{"id":"09603","title":"core unit","longtitle":"IUPAC Gold Book - core unit","doi":"10.1351\/goldbook.09603","code":"09603","status":"current","definitions":[{"id":1,"text":"Constitutional unit in a dendrimer molecule, from which the dendron(s) emanate(s).","notes":{"1":"The structure of the core unit may be identical to that of the constitutional repeating units.","2":"Occasionally, a dendrimer molecule may consist of two dendrons directly connected together.","3":"In a hyperbranched macromolecule obtained by the \\({\\rm{AB}}_{x}\\mbox{-}\\rm{type}\\) monomer + \\({\\rm{B}}_{y}\\mbox{-}\\rm{type}\\) monomer polycondensation approach, where \\(\\rm{A}\\) and \\(\\rm{B}\\) refer to mutually reactive groups, the terms core molecule (not acceptable) and core unit refer to the \\({\\rm{B}}_{y}\\mbox{-}\\rm{type}\\) unit, even though the structure of the macromolecule does not comprise dendrons."},"exams":{"1":" Representation of a regular dendrimer molecule highlighting the core unit and the dendrons. "},"links":[{"term":"dendrimer molecule","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/09605"},{"term":"dendrons","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/09611"}],"sources":["PAC, 2019, 91, 523. 'Nomenclature and terminology for dendrimers with regular dendrons and for hyperbranched polymers (IUPAC Recommendations 2017)' on page 527 (https:\/\/doi.org\/10.1515\/pac-2016-1217)"]}],"altoutputs":{"html":"https:\/\/goldbook.iupac.org\/terms\/view\/09603\/html","xml":"https:\/\/goldbook.iupac.org\/terms\/view\/09603\/xml","plain":"https:\/\/goldbook.iupac.org\/terms\/view\/09603\/plain"},"citation":"Citation: 'core unit' 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.09603","license":"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.","collection":"If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org .","disclaimer":"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.","accessed":"2026-07-25T18:36:31+00:00"}}