C₃H₉S⁺ is the chemical formula for the propylthio cation, which consists of three carbon atoms, nine hydrogen atoms, and one sulfur atom. This positively charged ion is often encountered in organic chemistry and can be formed through the protonation of propylthiol, a compound containing a sulfur atom bonded to a propyl group. The presence of the sulfur atom gives C₃H₉S⁺ unique properties, making it important in various chemical reactions. It can act as a nucleophile or participate in substitution reactions, contributing to the synthesis of more complex organic molecules in fields like pharmaceuticals and materials science.