Definition

Noun: 1. The state or condition of being an isomer: In chemistry, this refers to the phenomenon where two or more chemical compounds share the same molecular formula (same number and types of atoms) but have different arrangements of atoms in space, leading to distinct physical and/or chemical properties. 2. The complex of chemical and physical phenomena characteristic of isomers: This encompasses the study and observable effects resulting from the structural or spatial differences between isomers, such as variations in boiling point, reactivity, or biological activity.

Usage Examples

• The difference in sweetness between glucose and galactose is a classic example of isomerism in biochemistry.
• Understanding isomerism is fundamental to organic chemistry and drug design.
• The isomerism observed in these compounds explains their different behaviors in the reaction.

Advanced Usage

• Stereoisomerism: A subtype of isomerism where molecules have the same molecular formula and sequence of bonded atoms (constitution), but differ in the three-dimensional orientations of their atoms in space. This includes enantiomers (mirror-image isomers) and diastereomers.
  • The different pharmacological effects of the drug are due to stereoisomerism.
• Structural Isomerism (or Constitutional Isomerism): A subtype where molecules with the same molecular formula have atoms connected in a different order.
  • Butane and isobutane demonstrate structural isomerism.

Variants and Related Words

• Isomer (n): One of the compounds that exhibits isomerism.
  • These two molecules are isomers of each other.
• Isomeric (adj): Relating to or characterized by isomerism.
  • The substances have isomeric structures.
• Stereoisomer (n): An isomer related by stereoisomerism.
• Constitutional isomer (n): An isomer related by structural isomerism.

Synonyms

• Isomeric state
• Isomeric phenomenon

Related Phrases and Concepts

• Optical isomerism: A form of stereoisomerism involving molecules that are non-superimposable mirror images (enantiomers), often related to the rotation of plane-polarized light.
  • The study of optical isomerism is crucial for understanding chirality.
• Geometric isomerism (cis-trans isomerism): A form of stereoisomerism, often in alkenes or rings, where groups are positioned differently around a rigid structure.
  • The geometric isomerism in this compound affects its polarity.

Noun

1. the state of being an isomer; the complex of chemical and physical phenomena characteristic of isomers