Gero Grunewald

Pyridyl-endcapped molecular wires with photoexcitable subphthalocyanines attached to a rigid ethynylphenylene scaffold

Molecular electronics is a diverse field of research aimed at replacing parts of the traditional electronics architecture,^[1] such as switches, rectifiers, transistors and wires by individual molecules or molecular ensembles.^[2]

Molecular wires are distinct organic molecules that have appreciable electric conductivity and can therefore serve as elementary building blocks for nanoscale devices.^[3] In general, conductivity is achieved by applying a potential bias along a conjugated π-system.^[4] A second prerequisite for efficient molecular wiring is a so-called anchor group which ultimately connects the molecular wire to the metallic electrodes of the device.  In most cases, these electrodes consist of elemental gold,^[5] and typical connectors are thiol, amino or, less frequently, pyridyl groups.^[4]

The focus of my work is the synthesis and the characterization of a photoswitchable molecular wire with ethynyl phenylene backbone that is endcapped by pyridyl anchor groups. Photoactive subphthalocyanines (SubPc) will be attached to that backbone, in an effort to modulate the electron density and hence the conductivity along the wire by light irradiation.

[1]   F. C. Grozema, L. D. A. Siebbeles, Charge and Exciton Transport through Molecular Wires, 
        Wiley-VCH Verlag, 1. Ed., Weinheim, Germany, 2011.
[2]   J.-U. Holzhauer, Dissertation, Universität Kassel, 2016.
[3]   D. M. Guldi, H. Nishihara, L. Venkataraman, Chem. Soc. Rev. 2015, 44, 842–844.
[4]   P. Moreno-García, M. Gulcur, D. Z. Manrique, T. Pope, W. Hong, V. Kaliginedi, C. Huang, 
        J. Am. Chem. Soc. 2013, 135, 12228–12240.
[5]   C. Wang, A. S. Batsanov, M. R. Bryce, S. Martín, R. J. Nichols, S. J. Higgins, 
        V. M. García-Suárez, C. J. Lambert, J. Am. Chem. Soc. 2009, 131, 15647–15654.

G. Grunewald, S. Greve, R. Faust
“Molecular wires with pyridine anchor groups”, CINSaT autumn colloquium, Kassel, October 16, 2019.

G. Grunewald
“Molekulare Drähte mit Phenylenethinyl-Grundgerüst und Pyridyl-Endgruppen”, Masterarbeit, Universität Kassel, 2018.

G. Grunewald
“Kationische Chromophore durch S_N-Reaktionen an Polyphenylverbindungen”, Bachelorarbeit, Universität Kassel, 2015.