https://doi.org/10.1351/goldbook.08824
Constitutional isomerism of polymeric (oligomeric) chains composed of identical non symmetric repeating units consisting in different orientations of the units.
Notes:
- In the repeating unit of a vinyl polymer: \(\ce{-CHR-CH2\bond{-}}\), the substituent-bearing group \(\ce{CHR}\) is denoted 'head' (H) while the other one 'tail' (T). There exist three modes how two such units can be linked in a chain: head-to-tail (HT), head-to-head (HH) and tail-to-tail (TT).
- The uniformity/non-uniformity of repeating units’ orientation determines the regularity/irregularity of macromolecules.
See also: regioregular polymer
Source:
PAC, 2022, 94, 15. 'Glossary of terms relating to electronic, photonic and magnetic properties of polymers (IUPAC Recommendations 2021)' on page 34 (https://doi.org/10.1515/pac-2020-0501)
PAC, 2022, 94, 15. 'Glossary of terms relating to electronic, photonic and magnetic properties of polymers (IUPAC Recommendations 2021)' on page 34 (https://doi.org/10.1515/pac-2020-0501)