TY - CONF A1 - Hupatz, H. A1 - Schröder, H. A1 - Heinrich, Thomas A1 - Lippitz, Andreas A1 - Unger, Wolfgang A1 - Schalley, C. T1 - Deposition of redox-switchable rotaxanes on surfaces N2 - Deposition of Redox-switchable rotaxanes on surfaces Nature has created molecular machines which can perform a variety of different tasks. They exhibit defined operational pathways and order, resulting in directed macroscopic effects. Within the last decades researchers have been developing numerous artificial molecular machines which are so far mostly operating in solution. However, this represents a major obstacle for the generation of a macroscopic output, due to the random orientation of molecules in solution. As a general approach to this problem, interfaces have been used to generate ordered arrays of functional molecules. Recently, we developed a new class of redox-switchable crown ether/ammonium-based [2]- and [3]rotaxanes which incorporate redox-active tetrathiafulvalene and naphthalene diimide units in their wheels resulting in emergent optoelectronic properties. Electrochemical stimuli influence the interactions between the two macrocycles of [3]rotaxanes and induce conformational changes. In a proof-of-principle study [2]pseudorotaxanes were deposited on gold surfaces by “click”-reaction to azide-terminated self-assembled monolayers to generate ordered arrays of redox-active rotaxanes on-surface. X-ray photoelectron spectroscopy (XPS) confirms the successful deposition of a rotaxane monolayer, though angle-resolved near-edge X-ray absorption fine structure spectroscopy (NEXAFS) exhibits poor order of the rotaxanes. Following, new terpyridine-stoppered rotaxanes will be synthesised opening a pathway for the deposition of [2]- and [3]rotaxanes in a layer-by-layer metal-mediated self-assembly procedure. This approach would allow for a programmed sequence of different rotaxanes in multilayers. Electrochemical on-surface switching will be investigated by angle-resolved NEXAFS spectroscopy, XPS, cyclic voltammetry and UV/Vis spectroscopy. A more detailed understanding of the electron-transfer between the surface and the different rotaxane layers as well as of the on-surface switching could give rise to potential applications like optoelectric data-storage devices or potential-driven molecular motors. T2 - Gordon Research Conference - Artificial Molecular Switches & Motors CY - Holderness, NH, USA DA - 11.06.2017 KW - Rotaxane KW - Immobilization KW - XPS KW - NEXAFS PY - 2017 AN - OPUS4-42843 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hupatz, H. A1 - Schröder, H. V. A1 - Heinrich, Thomas A1 - Schalley, C.A. A1 - Unger, Wolfgang T1 - Redox-Switchable Rotaxanes on Surfaces N2 - Nature has created molecular machines which can perform a variety of different tasks. They exhibit defined operational pathways and order, resulting in directed macroscopic effects. Within the last decades researchers have been developing numerous artificial molecular machines which are so far mostly operating in solution. However, this represents a major obstacle for the generation of a macroscopic output, due to the random orientation of molecules in solution. As a general approach to this problem, interfaces have been used to generate ordered arrays of functional molecules. Recently, we developed a new class of redox-switchable crown ether/ammonium-based [2]- and [3]rotaxanes which incorporate redox-active tetrathiafulvalene and naphthalene diimide units in their wheels resulting in emergent optoelectronic properties. Electrochemical stimuli influence the interactions between the two macrocycles of [3]rotaxanes and induce conformational changes. In a proof-of-principle study [2]pseudorotaxanes were deposited on gold surfaces by “click”-reaction to azide-terminated self-assembled monolayers to generate ordered arrays of redox-active rotaxanes on-surface. X-ray photoelectron spectroscopy (XPS) confirms the successful deposition of a rotaxane monolayer, though angle-resolved near-edge X-ray absorption fine structure spectroscopy (NEXAFS) exhibits poor order of the rotaxanes. Following, new terpyridine-stoppered rotaxanes will be synthesised opening a pathway for the deposition of [2]- and [3]rotaxanes in a layer-by-layer metal-mediated self-assembly procedure. This approach would allow for a programmed sequence of different rotaxanes in multilayers. Electrochemical on-surface switching will be investigated by angle-resolved NEXAFS spectroscopy, XPS, cyclic voltammetry and UV/Vis spectroscopy. A more detailed understanding of the electron-transfer between the surface and the different rotaxane layers as well as of the on-surface switching could give rise to potential applications like optoelectric data-storage devices or potential-driven molecular motors. T2 - GDCh-Wissenschaftsforum Chemie CY - Berlin, Germany DA - 10.09.2017 KW - NEXAFS KW - Rotaxane KW - XPS KW - Surface characterization PY - 2017 AN - OPUS4-42848 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -