Resumen
We report the discovery of three new binary systems containing Hg-Mn stars in open clusters: NGC 2546-10, NGC 3532-155, and NGC 6025-14. We study also the peculiar binary NGC 2287-105 previously known. In the binary system NGC 2546-10 both components are HgMn stars. Besides Hg and Mn overabundance, NGC 6025-14 presents strong P and Ga lines, while NGC 3532-155 and NGC 2287-105 present enhanced Pt and Y. We present radial velocity curves and derive spectroscopic orbits. Their orbital periods are between 14 and 41 days and all of them are kinematic cluster members.
