Surface chemistry for organic-inorganic interfaces – a quantum chemical perspective

Ralf Tonner

Fachbereich Chemie & Material Sciences Center, Philipps-Universität Marburg, Germany

The interface between a solid inorganic substrate and an ordered adsorbate layer of organic molecules is of continued interest for the experimental and theoretical physics and chemistry community due to their promised application range, e.g. for building chemical sensors. Many fundamental aspects of these interfaces are not yet well understood and concerted efforts of the aforementioned communities are currently being undertaken.

Among the most challenging aspects in this context is the controlled formation of a highly ordered layer of organic molecules covalently bound to the semiconductor surface.[1] The high reactivity of the surface, the need for at best barrier-less adsorption of the organic molecule in the orientation required for further functionalization and the understanding of non-Langmuir behavior of multiple adsorption are some examples here.

Experimental endeavors can help to rationalize some of these aspects but some key quantities, for example reaction barriers and transition state structures, are available only to first principles methods. The talk will highlight aspects of surface chemistry for organic-inorganic interfaces that can be approached by theoretical methods. Special emphasis will be on the successful transfer of concepts from molecular chemistry to surface reactions that can lead to surprising insights in this field.[2]

Examples from our work on surface adsorption, reactivity and chemical bonding[3] of organic molecules with the silicon(001) surface will be used to highlight the strength of the approach.

[1] a) G. Mette, M. Dürr, R. Bartholomäus, U. Koert, U. Höfer, Chem. Phys. Lett. 556, 70 (2013); b) B. Shong, T. E. Sandoval, A. M. Crow, S. F. Bent, J. Phys. Chem. Lett. 6, 1037 (2015); c) G. Mette, M. Reutzel, R. Bartholomäus, S. Laref, R. Tonner, M. Dürr, U. Koert, U. Höfer, ChemPhysChem 15, 3725 (2014).

[2] J. Pecher, R. Tonner, submitted.

[3] M. Raupach, R. Tonner, J. Chem. Phys., 142, 194105 (2015).