diff --git a/docs/snc4mz.md b/docs/snc4mz.md index 1fb1381..fde0ac7 100644 --- a/docs/snc4mz.md +++ b/docs/snc4mz.md @@ -769,7 +769,24 @@ A **polyamide** has monomers connected via an amide linkage on both ends. !!! warning There should be a hydrogen attached to the nitrogen at the end of the amine. -### E-Z isomers +### E/Z isomers + +E/Z isomers are a generalised form of cis-trans isomers, where priority is determined by atomic number. If both sides with the higher atomic number are on the **same** side, the isomer is a Z-isomer (German: *ze zame zide*). E/Z isomers are placed at the beginning surrounded by parentheses. + +!!! example + (Z)-2-bromo-1-chloro-1-fluoroethene: + (Source: Kognity) + +If the atoms are of equal priority, the sum of atomic numbers that they are directly connected to are compared (double bonds count twice), repeating as necessary. + +!!! example + (Z)-1-chloro-1-fluoro-2-methyl-1-butene (left) and (E)-1-chloro-1-fluoro-2-methyl-1-butene (right). + (Source: Kognity) + +If there are multiple E/Z isomers, they are separated by commas and numbered according to their earliest position on the main chain. + +!!! example + (2Z, 3E)-R ### Optical isomers