Class of helix

Term · Chemistry · MLC-T-CHM-002100

The count of backbone atoms in one residue of a helical chain, where the residue is the unit repeated by the helical symmetry. Isotactic polypropylene, whose residue is one monomer unit with two backbone atoms, is a class 2 helix, whereas polytetrafluoroethylene, with one backbone atom per residue, is class 1. It is separate from the u/t notation, such as 3/1, which gives the number of residues in a number of turns.

Table 1. Record
Identifier	MLC-T-CHM-002100
Field	Chemistry
Subject	Polymer
References	Purple Book, 1st ed., p. 79 (http://old.iupac.org/publications/books/author/metanomski.html)
See also	Helix

Record as JSON

{
  "id": "MLC-T-CHM-002100",
  "term": "Class of helix",
  "field": "Chemistry",
  "definition": "The count of backbone atoms in one residue of a helical chain, where the residue is the unit repeated by the helical symmetry. Isotactic polypropylene, whose residue is one monomer unit with two backbone atoms, is a class 2 helix, whereas polytetrafluoroethylene, with one backbone atom per residue, is class 1. It is separate from the u/t notation, such as 3/1, which gives the number of residues in a number of turns.",
  "subject": "Polymer",
  "see_also": [
    "helix"
  ],
  "references": [
    "Purple Book, 1st ed., p. 79 (http://old.iupac.org/publications/books/author/metanomski.html)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/class-of-helix/"
}

Record 2,249 of 13,676 in Chemistry terminology (MLC-0109). Request the full dataset.