C7H5Cl3O

C7H5Cl3O is the chemical formula representing several isomeric chlorinated anisoles, a class of aromatic ethers derived from anisole (methoxybenzene) with three chlorine substituents. The most well-known isomer with this formula is 2,4,6-trichloroanisole (TCA). In this structure, the methoxy group is attached to the benzene ring, with chlorine atoms at the 2, 4, and 6 positions, giving a symmetrical arrangement around the ring.

TCA and related isomers are typically colorless solids or liquids with low water solubility and notable volatility. They are renowned for their very low odor thresholds, capable of producing perceptible musty or moldy aromas at trace levels. Because of their volatility and persistence, these compounds can migrate from contaminated sources into consumer products such as wine, where they are most famously associated with cork taint.

Occurrence and formation: TCA can form during cork processing or storage through reactions involving chlorinated compounds and anisole precursors, as well as via microbial processes in cork environments. While TCA is the best-known member of this formula class due to sensory impact, other 2,4,6- or positional isomers (and related trichloroanisoles) also share the same molecular formula.

Applications and safety: There are no major industrial uses for TCA beyond its study as a sensory contaminant and environmental odorant. It is not considered highly toxic, but its potent odor makes it a significant concern in enology and food/beverage quality control. See also cork taint and trichloroanisoles.