Compounds with both positive and negative charges can be made in abundance thanks to a method developed by scientists in France.   

The molecules, zwitterionic benzoquinonemonoimines, could be used in making colourants or catalysts. 

Unlike previous multi-step approaches this new procedure, where diaminoresorcinol reacts with an amine, can take place in water in a single vessel without organic solvents - thereby being a 'greener' one-pot synthesis. 

This transamination reaction has not been seen for this type of quinine before. Pierre Braunstein and colleagues at the Université Louis Pasteur in Strasbourg found that careful amine choice allowed them to tailor the solubility of the final product and specify its functional groups. 

One product had a long coordinating 'arm' that allowed it to form a complex with zinc ions, others formed supramolecular structures held together by hydrogen bonds. Braunstein expects this type of molecule to 'open new possibilities in coordination and supramolecular chemistry'.   

Michael Smith