open-chain

IPA/ˈəʊpəntʃˈeɪn/
IPA/ˈoʊpəntʃˈeɪn/

open-chain — phrase

1. describing or naming a molecular structure made of connected atoms whose two end

1.phraseC2
Definition

describing or naming a molecular structure made of connected atoms whose two ends stay separate instead of closing into a ring

Example

Professor Lin drew an open-chain sugar on the board before showing its ring form.

contrast: open-chain form vs ring form

The lab sheet calls fructose open-chain only when the ends stay apart.

used for a molecule whose ends do not join

Common collocations
  • open-chain structure
  • open-chain form
  • open-chain compound
  • open-chain molecule
  • open-chain sugar
Synonyms
  • acyclic

    is the technical near-equivalent and is common in formal scientific writing

  • noncyclic

    is a more explicit scientific label that directly contrasts with cyclic forms

Antonyms
  • cyclic

    describes a structure whose atoms join to form a ring

  • ring-shaped

    is a broader plain-English description of a ring form

Grammar Patterns

open-chain structure

open-chain form

open-chain molecule

Usage Note

Mainly used in chemistry to contrast a straight or branched chain with a cyclic structure. It often appears before nouns such as form, structure, compound, or molecule.

Common Mistakes

The diagram shows a chain-open form.
The diagram shows an open-chain form.
In chemistry this idea is normally expressed with the fixed order 'open-chain'.

Etymology

English

The term combines open with chain to describe a chain of atoms that does not close back on itself. In chemistry it became the standard contrast to ring or cyclic structures.