Hydrohalogenic

Hydrohalogenic is an adjective relating to hydrohalic acids or processes involving hydrogen halides. In practice, it is often used to describe reagents, conditions, or reactions that involve hydrogen halides such as HCl, HBr, HI, or HF. The term is less common in modern usage; more standard terms are hydrohalic and hydrohalogenation.

In organic chemistry, hydrohalogenation refers to the electrophilic addition of a hydrogen halide to unsaturated substrates, especially alkenes and alkynes. The reaction forms a carbon–halogen bond and a saturated product, typically following Markovnikov regioselectivity for most HX additions. For example, ethene reacting with hydrogen chloride yields chloroethane. The presence of peroxides can switch the outcome for HBr to anti-Markovnikov orientation.

Hydrohalic acids are strong acids in aqueous solution, and hydrogen halide reagents are widely used to install halogen atoms into molecules, to open rings, or to activate substrates in various synthetic sequences. HF is notably hazardous and requires special handling due to its unique chemistry with silicon and its toxicity; HCl, HBr, and HI are corrosive gases or liquids handled under controlled conditions.

In summary, hydrohalogenic describes activities or reagents involving hydrogen halides, with hydrohalogenation being a foundational reaction type in organic synthesis. The term emphasizes the relationship to hydrohalic acids, but is often supplanted by more specific language referring to the particular reagent or reaction.