Isomers and Chirality in Organic Chemistry

These flashcards cover key concepts about isomers, chirality, and stereochemistry from Organic Chemistry.

What are isomers?

Compounds that have the same molecular formula but different structures.

What is a constitutional isomer?

Isomers that differ in the way the atoms are connected.

What are cis–trans isomers?

Isomers that result from restricted rotation, having substituents on the same (cis) or opposite (trans) sides of a double bond or ring.

What defines chiral molecules?

Chiral molecules have an asymmetric center, meaning an atom is attached to four different groups.

What is an enantiomer?

Isomers that are nonsuperimposable mirror images of each other.

What is the absolute configuration of a chiral center?

Determined by R-S sequencing rules based on the priority of substituents.

What is optical activity?

The ability of a chiral compound to rotate the plane of polarized light.

What distinguishes achiral compounds from chiral compounds?

Achiral compounds have superimposable mirror images, indicating they are identical molecules.

Define diastereomers.

Stereoisomers that are not enantiomers and have different physical and chemical properties.

What is a meso compound?

A compound with multiple asymmetric centers that has a superimposable mirror image, making it optically inactive.

What role do double bonds play in isomers?

Double bonds restrict rotation, leading to geometric isomerism (cis-trans).

What is enantiomeric excess?

The measure of the excess of one enantiomer over the other in a mixture.

What are the three types of isomers covered in the notes?

Constitutional isomers, cis-trans isomers, and chiral molecules.

What is the significance of a polarimeter in studying optical activity?

It measures the optical rotation of compounds to determine their specific rotation.

How can chiral chromatography be useful?

It separates chiral compounds based on their different interactions with stationary phases.

What is the general rule for identifying asymmetric centers?

An asymmetric center is attached to four different groups.