Direct Experimental Evidence for Substrate Adatom Incorporation into a Molecular Overlayer

P. J. Mouslez, L. A. Rochford, P. T. P. Ryan, P. Blowey, J. Lawrence, D. A. Duncan, H. Hussain, B. Sohail, T.-L. Lee, G. R. Bell, G. Costantini, R. J. Maurer, C. Nicklin, D. P. Woodruff, J. Phys. Chem. C 126, 7346 - 7355 (2022)

"We present the results of a detailed structural study of the Au(111)-F₄TCNQ system, combining surface characterization by STM, low-energy electron diffraction, and soft X-ray photoelectron spectroscopy with quantitative experimental structural information from normal incidence X-ray standing wave (NIXSW) and SXRD, together with dispersion-corrected density functional theory (DFT) calculations. SXRD measurements provide unequivocal evidence for the presence and location of Au adatoms, while the DFT calculations show this reconstruction to be strongly energetically favored"

Design Principles for Metastable Standing Molecules

H. H. Arefi, D.Corken, F. S.Tautz, R. J. Maurer, C. Wagner, J. Phys. Chem. C 126, 6880-6891 (2022)

"Here, we use density functional theory to study 3,4,9,10-perylene-tetracarboxylic dianhydride (PTCDA) standing on the Ag(111) surface as well as on the tip of a scanning probe microscope. We cast our results into a simple set of design principles for such metastable structures, the validity of which we subsequently demonstrate in two computational case studies. Our work proves the capabilities of computational nanostructure design in the field of metastable molecular structures and offers the intuition needed to fabricate new devices without tedious trial and error."

Thermodynamic Driving Forces for Substrate Atom Extraction by Adsorption of Strong Electron Acceptor Molecules

P. Ryan, P. J. Blowey, B. S. Sohail, L. A. Rochford, D. A. Duncan, T.-L. Lee, P. Starrs, G. Costantini, R. J. Maurer, J. Phys. Chem. C 126, 6082-6090 (2022)

"A quantitative structural investigation is reported, aimed at resolving the issue of whether substrate adatoms are incorporated into the monolayers formed by strong molecular electron acceptors deposited onto metallic electrodes. A combination of X-ray standing waves, STM, and DFT show that there is an energetic driving force for adatom incorporation into adsorbate structures of the strong acceptor F₄TCNQ on Ag(100) but not for the weaker acceptor TCNQ."

The stabilization potential of a standing molecule

Marvin Knol, Hadi H. Arefi, Daniel Corken, James Gardner, F. Stefan Tautz, Reinhard J. Maurer, and Christian Wagner, Science Advances 7, eabj9751 (2021)

"Here, we combine scanning probe experiments with ab initio potential energy calculations to investigate the thermal stability of a prototypical standing molecule. We reveal its generic stabilization mechanism, a fine balance between covalent and van der Waals interactions including the latter's long-range screening by many-body effects, and find a remarkable agreement between measured and calculated stabilizing potentials."

Warwick University Press Release

The Structure of VOPc on Cu(111): Does V═O Point Up, or Down, or Both?

P.J.Blowey. R.J.Maurer, L.A.Rochford, D.A.Duncan, J.-H.Kang, D.A.Warr, A.J.Ramadan, T.-L.Lee, P.K.Thakur, G.Constantini, K.Reuter and D.P.Woodruff The Journal of Physical Chemistry C 123, 8101-8111, (2019)

"The local structure of the nonplanar phthalocyanine, vanadyl phthalocyanine (VOPc), adsorbed on Cu(111) at a coverage of approximately one-half of a saturated molecular layer, has been investigated by a combination of normal-incidence X-ray standing waves (NIXSW), scanned-energy mode photoelectron diffraction (PhD), and density-functional theory (DFT), complemented by scanning tunnelling microscopy (STM)."

Switching of an Azobenzene-Tripod Molecule on Ag(111)

Katharina Scheil, Thiruvancheril G. Gopakumar, Julia Bahrenburg, Friedrich Temps, Reinhard J. Maurer, Karsten Reuter, Richard Berndt, J. Phys. Chem. Lett. 7, 2080-2084 (2016)

We observe and interpret the mechanism of multistate switching of an Azobenzene Tripod on Ag(111) using STM, STS and Density Functional Theory.

Spin manipulation by creation of single-molecule radical cations

S. Karan, N. Li, Y. Zhang, Y. He, I-P. Hong, H. Song, J.-T. Lü, Y. Wang, L. Peng, K. Wu, G. S. Michelitsch, R. J. Maurer, K. Diller, K. Reuter, A. Weissmann, and R. Berndt, Phys. Rev. Lett., 116, 027201 (2016)

We investigate magnetic switching of all-trans-retinoic acid adsorbed on a Au(111) surface using Scanning Tunneling Microscopy and Density Functional Theory.

Broken Symmetry of an Adsorbed Molecular Switch Determined by Scanning Tunneling Spectroscopy

T. G. Gopakumar, T. Davran-Candan, J. Bahrenburg, R. J. Maurer, F. Temps, K. Reuter, R. Berndt, Angew. Chem. Int. Ed. 52, 11007-11010 (2013)

Using STM and DFT we investigate the reasons for electronic state splitting for an adsorbed molecular switch