���˾þ�

���˾þ�s in Germany are claiming to have created the world’s smallest
chemical reaction. Saw-Wai Hla and his colleagues at the Free University of
Berlin (Physical Review Letters, vol 85, p 2777)
blasted electrons at iodobenzene molecules (C₆H₅I) and
separated and herded away the iodine using a scanning tunnelling microscope tip.
Next, they dragged two phenyl (C₆H₅) free radicals together
and squirted electrons at them to make them react. This welded them together to
form a biphenyl (C₁₂H₁₀) molecule. The technique could be used
for making new molecules not found in…