Fresh evidence suggests there exists a type of chemical bond that nobody has ever seen before, Chemistry World reports.
Not that they haven't looked. In the early 1980s, chemists searched for--but couldn't find--evidence of this type of bond after some theorized it should exist. The bond occurs between two heavy atoms with a hydrogen atom, which is light, in the middle. Normally, chemical bonds only happen when the bonding reduces the potential energy of the system. In this case, the potential energy of the system is higher after bonding. Still, the bond appears because something called the vibrational zero point energy decreases so much, it stabilizes the system. The bond is called a vibrational bond.
Now, two recent experiments found evidence of a bromine-hydrogen-bromine molecule with vibrational bonding, Chemistry World reports. One found the bond by creating exotic versions of hydrogen. The discovering team created isotopes of hydrogen by replacing hydrogen's electrons with exotic particles called muons. Only muonium made vibrational bonds with the bromine atoms.