Topicity
（重定向自Homotopicity）
![Figure 1. Diastereotopic hydrogens in achiral compounds.](/Images/godic/202501/18/DIASTERE2922.png")
![Figure 2. Diastereotopic hydrogens in a chiral metal complex.](/Images/godic/202501/18/DIASTER22922.png")
In stereochemistry, topicity is the stereochemical relationship between substituents and the structure to which they are attached. Depending on the relationship, such groups can be heterotopic, homotopic, enantiotopic, or diastereotopic.