spacer arm

https://doi.org/10.1351/goldbook.09031
Link used in a conjugation to distance the substrate from the active species that otherwise would have its activity affected by steric or other influences.
Source:
PAC, 2022, 94, 559. (Terminology and the naming of conjugates based on polymers or other substrates (IUPAC Recommendations 2021)) on page 563 [Terms] [Paper]