configurational base unit

in polymers
https://doi.org/10.1351/goldbook.C01250
A @[email protected] in a @[email protected], a @[email protected], @[email protected] or a regular @[email protected], the configuration of which is defined at least at one site of @[email protected] in the @[email protected]
Source:
PAC, 1996, 68, 2287. (Glossary of basic terms in polymer science (IUPAC Recommendations 1996)) on page 2291 [Terms] [Paper]