Microwave spectroscopy of silver hydrosulfide AgSH

► The rotational spectrum of AgSH was observed in a dc discharge absorption cell. ► The spectra of AgSH correspond to that of a near-prolate asymmetric top. ► A harmonic force field analysis enabled the determination of the rz structure of AgSH and CuSH. ► AgSH and CuSH possess highly bent structures indicating considerable covalent character.