What are isomers?

Isomers are compounds with the same molecular formula, which means that although they are composed of the same number of atoms of the same type, they are different in spatial structure or arrangement For example, pentane is an organic compound composed of five carbon atoms and 12 hydrogen atoms The two isomers of pentane include unbranched pentane (carbon arranged in a linear chain), and isopentane or methyl butane There are four carbon atoms arranged in a linear chain, and the fifth one branches from one of the internal carbon atoms These pentanes all have the same molecular formula, but the actual arrangement of atoms is different Isomers are important because compounds with different structures can have very different chemical properties even if they contain the same atoms Compounds with the same molecular formula may be completely different in structure First of all, the structural isomers are different in the actual molecular structure arrangement The groups that make up the compound are combined in different ways and arrangements On the other hand, the group positions of stereoisomers are arranged in the same way, but the spatial relative positions are different For example, two molecules with the same atom and structure, but if they are non overlapping images, they are also isomers Although there is no difference in the appearance of stereoisomers, their chemical properties may be completely different For example, a compound is an important active component of a drug, but its non overlapping mirror isomer may be invalid or even harmful Compounds with different arrangements often react with other atoms and compounds in different ways Many chemical reactions produce mixtures of different isomers, which is especially common in stereoisomers, so chemists often use different methods to separate specific isomers Many methods based on different chemical properties can be used to separate isomers For example, some compounds with the same molecular formula will boil at different temperatures, so they can be separated by distillation Other reactions with different compounds, such as chemical reactions, can be used to remove an isomer, leaving only the desired compound.