metaisomers
Metaisomers are a specific type of constitutional isomer in organic chemistry. Constitutional isomers, also known as structural isomers, are molecules that share the same molecular formula but differ in the connectivity of their atoms. Metaisomers are a subclass of constitutional isomers that specifically arise when two functional groups of the same type are positioned meta to each other on a benzene ring. The "meta" position refers to the 1,3 substitution pattern on the aromatic ring. For example, if you have a benzene ring with two methyl groups attached, the molecule where the methyl groups are at positions 1 and 3 is a metaisomer. This is in contrast to ortho isomers (1,2 substitution) and para isomers (1,4 substitution). The difference in the relative positions of these functional groups leads to distinct physical and chemical properties for the metaisomers compared to their ortho and para counterparts, even though they have the same number of each type of atom. This distinction is crucial in understanding the behavior and reactivity of substituted aromatic compounds.