kekule structure
C2Technical/Scientific
Definition
Meaning
A specific representation of the molecular structure of benzene as a six-membered carbon ring with alternating single and double bonds, proposed by August Kekulé.
In modern chemistry, the term often refers to any of the two equivalent resonance structures of benzene, or more broadly, to the classical line-bond representation of aromatic compounds before the full adoption of delocalized orbital theory.
Linguistics
Semantic Notes
The term is highly specific to organic chemistry. It denotes a historical model that is now understood as a resonance hybrid, not an accurate depiction of electron distribution. It is often used when teaching the concept of aromaticity and resonance.
Dialectal Variation
British vs American Usage
Differences
No significant differences in meaning or usage. Spelling of 'Kekulé' may sometimes appear without the accent in informal American texts.
Connotations
Identical in both dialects: carries connotations of foundational chemical history, simplification, and pedagogical stepping stone.
Frequency
Used with identical frequency in academic and research chemistry contexts in both the UK and US.
Vocabulary
Collocations
Grammar
Valency Patterns
the Kekulé structure for [compound]the Kekulé structure proposed by [scientist]a Kekulé structure representationVocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “It's a Kekulé nightmare (humorous, for a complex aromatic system)”
Usage
Context Usage
Business
Not used.
Academic
Used in chemistry textbooks, lectures, and papers when discussing the history of aromaticity or teaching basic organic chemistry.
Everyday
Virtually never used.
Technical
Core term in organic chemistry education and historical discussions; used by chemists.
Examples
By Part of Speech
verb
British English
- We need to kekulise the naphthalene system to draw its classical forms.
- Early chemists attempted to kekulise all aromatic compounds.
American English
- The student was asked to Kekulize the aromatic molecule.
- You can't properly Kekulize a molecule like pyridine without considering the heteroatom.
adverb
British English
- The molecule was depicted kekule-style in the textbook.
- He thought kekule-ly about the bonding problem.
American English
- It's drawn Kekule-fashion, with alternating bonds.
- The compound is represented Kekule-wise for simplicity.
adjective
British English
- The kekulean representation is a useful teaching tool.
- He had a kekulean insight about the ring's structure.
American English
- The Kekulean model predates quantum mechanics.
- Her explanation was purely Kekulean in nature.
Examples
By CEFR Level
- The Kekulé structure shows a ring with double bonds.
- Benzene has a special structure called a Kekulé structure.
- Although the Kekulé structure is not perfectly accurate, it helps visualise benzene.
- You must draw the two possible Kekulé structures for benzene to demonstrate resonance.
- The historical significance of Kekulé's proposal lies in his postulation of alternating single and double bonds, a concept that paved the way for resonance theory.
- Critics of the simple Kekulé structure point to its failure to account for benzene's lack of reactivity towards addition reactions.
Learning
Memory Aids
Mnemonic
Imagine a snake (the Ouroboros from Kekulé's dream) biting its tail to form a ring with alternating segments of skin (single bonds) and scale patterns (double bonds).
Conceptual Metaphor
HISTORICAL MODEL IS A SNAPSHOT (It captures a static, simplified image of a dynamic, complex reality).
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Avoid translating 'structure' as 'строение' in a general sense; the term is a fixed name. 'Структура Кекуле' is the direct equivalent.
- Do not confuse with 'формула Кекуле', which is also acceptable.
Common Mistakes
- Pronouncing it as 'keh-koo-lee'.
- Using it to describe the modern, delocalized model of benzene.
- Writing 'Kekule' without the accent when formal accuracy is required.
Practice
Quiz
What does the Kekulé structure primarily represent?
FAQ
Frequently Asked Questions
It is a useful but incomplete model. It correctly represents the connectivity of atoms in benzene but inaccurately depicts the bonding, which is delocalized. It is best understood as one of two contributing resonance structures.
It is named after August Kekulé, a German chemist who, in 1865, proposed the cyclic structure with alternating single and double bonds for benzene, solving a major problem in understanding its formula.
Benzene has two equivalent Kekulé structures. They differ only in the placement of the three double bonds and are used together to describe the molecule's resonance hybrid.
Yes, but primarily as a pedagogical tool to introduce the concept of benzene and resonance. In advanced research, the delocalized molecular orbital model is standard, though Kekulé forms may still be used in shorthand or mechanistic drawings.