Stereoisomers have the same connectivity but different spatial arrangements from "summary" of Organic Chemistry by John E. McMurry
Stereoisomers are compounds that have the same molecular formula and connectivity of atoms, but differ in the spatial arrangement of their atoms. This difference in spatial arrangement can result in stereoisomers having different physical and chemical properties. For example, stereoisomers may have different melting points, boiling points, solubility, and biological activity, even though they have the same atoms bonded together in the same order. One type of stereoisomer is known as geometric isomers or cis-trans isomers. Geometric isomers have restricted rotation around a double bond or ring, leading to different spatial arrangements of atoms. In cis isomers, similar groups are on the same side of the double bond or ring, while in trans isomers, similar groups are on opposite sides. This difference in spatial arrangement can result in different physical and chemical properties between cis and trans isomers. Another type of stereoisomer is known as optical isomers or enantiomers. Enantiomers are non-superimposable mirror images of each other, meaning that they are like left and right hands. Enantiomers have the same physical properties, such as melting points and boiling points, but differ in their interaction with plane-polarized light. One enantiomer will rotate plane-polarized light clockwise (dextrorotatory), while the other enantiomer will rotate plane-polarized light counterclockwise (levorotatory).- The concept of stereoisomers having the same connectivity but different spatial arrangements is crucial in understanding the diversity and complexity of organic compounds. By recognizing and studying stereoisomers, chemists can gain insights into how slight changes in spatial arrangement can lead to significant differences in properties and reactivity.
