Halogen bonds (X-bonds) are shown to be geometrically perpendicular to and energetically independent of hydrogen bonds (H-bonds) that share a common carbonyl oxygen acceptor. This orthogonal ...

Astronomers finally found molecular oxygen beyond the Milky Way, but they had to look at a galaxy far, far away: the quasar Markarian 231, shown here in an image from the Hubble Space Telescope.