mesomerism: meaning, definition, pronunciation and examples
Low / Very TechnicalHighly technical/scientific, formal
Quick answer
What does “mesomerism” mean?
The phenomenon in chemistry where the true structure of a molecule is represented as a weighted average (resonance hybrid) of two or more contributing structures (resonance structures), due to the delocalization of electrons.
Audio
Pronunciation
Definition
Meaning and Definition
The phenomenon in chemistry where the true structure of a molecule is represented as a weighted average (resonance hybrid) of two or more contributing structures (resonance structures), due to the delocalization of electrons.
The concept describing electron delocalization in molecules, leading to stabilization and properties that cannot be represented by a single Lewis structure. In a broader, less common sense, it can refer to a middle state or intermediate condition in other fields.
Dialectal Variation
British vs American Usage
Differences
The term 'mesomerism' and the 'mesomeric effect' are more prevalent in British and European chemical literature. In American English, 'resonance' and the 'resonance effect' are overwhelmingly preferred.
Connotations
Identical scientific meaning, but regional preference in terminology signals the educational background of the speaker/writer.
Frequency
'Mesomerism' is very low frequency in general English but has moderate frequency in UK/EU chemical texts. It is rare in US chemical texts, where 'resonance' is standard.
Grammar
How to Use “mesomerism” in a Sentence
The mesomerism of [molecule/ion] + [verb e.g., stabilises, explains, results in][Property/Phenomenon] is attributed to mesomerism.Mesomerism accounts for [observation].Vocabulary
Collocations
Examples
Examples of “mesomerism” in a Sentence
verb
British English
- The molecule is mesomeric, with the charge delocalised across the ring.
American English
- The structure is described as having resonance; 'mesomerize' is not a standard verb.
adjective
British English
- The mesomeric effect of the nitro group withdraws electron density.
- We must consider all mesomeric structures.
American English
- The resonance structures are crucial for understanding stability. ('Mesomeric' is rarely used.)
Usage
Meaning in Context
Business
Not used.
Academic
Exclusively in advanced chemistry textbooks, papers, and lectures, particularly in physical and organic chemistry.
Everyday
Never used.
Technical
Core term in theoretical chemistry for describing molecular structure and stability.
Vocabulary
Synonyms of “mesomerism”
Strong
Neutral
Weak
Vocabulary
Antonyms of “mesomerism”
Watch out
Common Mistakes When Using “mesomerism”
- Pronouncing it /ˈmiːzəʊmərɪzəm/.
- Using it in non-chemical contexts.
- Thinking it describes a molecule rapidly switching between forms (it's a static hybrid).
FAQ
Frequently Asked Questions
Yes, in their core scientific meaning, they describe the same concept of electron delocalization. 'Mesomerism' is favoured in British/European English, while 'resonance' is standard in American English.
No. This is a common misconception. Mesomerism/resonance describes a single, stable hybrid structure with delocalized electrons. The contributing structures are not real, independent entities.
It is a specialized term used almost exclusively in chemistry, particularly in organic and physical chemistry, to explain molecular structure and stability.
No. It is a very low-frequency, highly technical term not encountered outside of advanced chemistry education or research literature.
The phenomenon in chemistry where the true structure of a molecule is represented as a weighted average (resonance hybrid) of two or more contributing structures (resonance structures), due to the delocalization of electrons.
Mesomerism is usually highly technical/scientific, formal in register.
Mesomerism: in British English it is pronounced /mɪˈzɒmərɪz(ə)m/, and in American English it is pronounced /məˈzɑːməˌrɪzəm/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “No established idioms”
Learning
Memory Aids
Mnemonic
Think 'ME-so-ME-rism': the true molecule is a MEan (average) of ME (multiple electronic) structures.
Conceptual Metaphor
A SINGLE AVERAGE PHOTOGRAPH (the real molecule) created by merging/blending several slightly different portrait sketches (the resonance contributors).
Practice
Quiz
Which term is most synonymous with 'mesomerism' in chemistry?