Free Republic

Raman spectroscopy souped up with scanning tunnelling microscopy hones in on individual atoms and bonds. Prepare to take flight across the surface of a molecule. An unprecedented window on the nanoscale world lets you feel the heft of the atoms beneath and test the strength of the chemical bonds that hold them together. This vision is now a reality, thanks to a system reported in this week's Nature1 that combines the best features of two imaging techniques: Raman spectroscopy and the scanning tunnelling microscope (STM). “It enables you to look at the guts of a molecule,” says Joanna Atkin, a...

Enlarge Image Shadow of the orbitals. The pictures on the left show the highest occupied molecular orbital (top) and the lowest unoccupied molecular orbital (bottom) of pentacene, as mapped by the STM. The pictures on the right show the same orbital structures, calculated mathematically. Credit: Adapted from L. Gross et al., PRL, 107 (2011) If you took high school chemistry, then you undoubtedly recall the bizarre drawings of the "orbitals" that describe where in an atom or a molecule an electron is likely to be found. Resembling strange clouds with multiple lobes, the shapes and orientation of the orbitals...