2021 AIP summer meeting

The AIP summer meeting was a hybrid event this year 6-9 Dec. ’21 with the border restrictions still in place preventing us from travelling to Brisbane.

Iolanda kindly invited me to talk about Marina’s MgPc hybridization work as well as new results of orbital tomography performed at the Australian Synchrotron (in preparation).

Ben Lowe contributed a talk to the scanning probe microscopy focus session, with an update on how we’re closing in on understanding the mechanism of formation for some unusual metal-organic products identified with ncAFM measurements.

Thanks also to Peggy Schönherr, Peggy Zhang, Peter Jacobson, and Iolanda DiBernardo for contributing talks to the SPM focus session.

Bernard Field talked about how he’s pushing forward how we can rationalise our observations of self-assembled MOF structures, stemming from our recently published experimental results that Agustin talked about in the MOF focus session.

MgPc-MgPc Hybridization

ncAFM atomic registration of MgPc molecule on Ag100
nc-AFM atomic registration of single MgPc molecule on Ag100 (surface atoms top and bottom stripes)

Marina Castelli studied the phthalocyanine containing magnesium (MgPc) via 5K scanned probe microscopies extensively during her PhD.

‘Routine’ STM characterisation showed that the molecules were interacting with one another on the Ag100 surface.

ncAFM showed identical contrast for all molecules, pointing to an electronic origin to the observed changes in appearance.

Our key observation was to track the shape of the occupied LUMO for different pairwise distances, an electronic feature that otherwise remained isoenergetic.

With multipass dI/dV mapping we were able to quantitatively track from four- to two-fold rotational symmetry, over distances out to ~3 nm. We found the spatial extent of this attractive hybridization quite surprising.

“Long-Range Surface-Assisted Molecule-Molecule Hybridization”, Small (2021). 10.1002/smll.202005974

FLEET PR
ArXiv link

STM image of MgPc molecules on Ag100 surface
STM image showing the neighbor-induced symmetry reduction