orthomethyl

Ortho-methyl is a term used in organic chemistry to describe the position of a methyl group substituent on an aromatic ring that is adjacent to another substituent. This specific positional isomerism is part of a larger system of nomenclature for disubstituted aromatic compounds, which also includes meta and para. In the ortho position, the two substituents are located on carbon atoms that are next to each other, often referred to as the 1,2 positions on the ring. This proximity of substituents can influence the chemical reactivity and physical properties of the molecule due to steric and electronic effects. For example, the ortho position can lead to increased steric hindrance, potentially affecting the rate or outcome of reactions occurring at or near these substituents. The electronic effects can involve inductive or resonance interactions between the two adjacent groups, modifying the electron density distribution of the aromatic ring. While "ortho-methyl" itself is descriptive, it is typically used in conjunction with the name of the parent aromatic compound and the other substituent to fully identify a specific chemical substance. For instance, ortho-methylanisole refers to anisole with a methyl group at the ortho position.