Up till now, we know of two types of binding:
ionic -where electrons from one atom hop over to another
covalent -where electrons are shared between atoms
But now, there's a third we know about! (maybe more?)
perpendicular paramagnetic bonding!
"The team first examined how the lowest energy state, or ground state, of a two-atom hydrogen molecule was distorted by the magnetic field. The dumb-bell-shaped molecule oriented itself parallel to the direction of the field and the bond became shorter and more stable, says Helgaker. When one of the electrons was boosted to an energy level that would normally break the bond, the molecule simply flipped so that it was perpendicular to the field and stayed together.
"We always teach students that when an electron is excited like this, the molecule falls apart," says Helgaker. "But here we see a new type of bond keeps the atoms hanging together." The team also reports that a similar effect should occur between helium atoms, which normally don't bond at all.
The atoms are held together by the way their electrons dance around the magnetic-field lines, explains Helgaker. "The way electrons move relative to the field, and their kinetic energy, can become as important for chemical bonding as the electrostatic attraction between the electrons and the nuclei," he says. Depending on their geometry, molecules will turn to allow electrons to rotate around the direction of the magnetic field.
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more info
HERE
