Positive-positive: They said it couldn't be done

Positively charged molecules repel each other – at least that’s how it typically works. A recent experiment suggests, however, there are exceptions to the rule.

For the first time a team from the University of Copenhagen’s (UCPH) chemistry department has bonded positively charged phosphorus atoms with positively charged hydrogen ones. Their insight may prove pivotal to understanding how biologically important molecules such as DNA and proteins form properly.

Function follows form where proteins are concerned. Whether they serve as signaling agents, catalysts, or biological building blocks, proteins are only effective if their molecular structure is spot on.

Their composition is largely dependent on hydrogen atoms in the molecules, and the ability of these to create hydrogen bonds with other elements.

An entirely new understanding

Previously, researchers assumed that positively charged hydrogen could only create hydrogen bonds with negatively charged elements like oxygen, fluorine, and nitrogen.

The discovery that positive hydrogen can also bind to positive phosphorus provides the basis for an entirely new understanding of how atomic charge works.

”It was thought that atomic charge was global, that is, as something that was uniform and spherically shaped. But our experiment demonstrates, as clear as day, that charge is asymmetric – that small areas of positive charge exist upon atoms which are in fact negative,” says Henrik Kjaergaard, a chemistry professor at UCPH.

Kjaergaard and colleagues describe the work in the Journal of Physical Chemistry Letters.

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