Sulfonamide
= Sulfonamide
A <sulfonamide> contains a sulfur(VI)-nitrogen linkage of the form $\mathrm{R-SO_2-NR'R''}$. It differs from a carboxamide, whose nitrogen is attached to a carbonyl carbon.
The sulfonyl group strongly influences nitrogen's electronic environment and acid-base behavior. Substituent choice can alter acidity, hydrogen bonding, and molecular recognition, so sulfonamide denotes a functional family rather than one compound.