With the introduction of single-molecule force spectroscopy (SMFS) it has become possible to directly access the interactions of various molecular systems. A bottleneck in conventional SMFS is collecting the large amount of data required for statistically meaningful analysis. Currently, atomic force microscopy (AFM)-based SMFS requires the user to tediously 'fish' for single molecules. In addition, most experimental and environmental conditions must be manually adjusted. Here, we developed a fully automated single-molecule force spectroscope. The instrument is able to perform SMFS while monitoring and regulating experimental conditions such as buffer composition and temperature. Cantilever alignment and calibration can also be automatically performed during experiments. This, combined with in-line data analysis, enables the instrument, once set up, to perform complete SMFS experiments autonomously.

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Titanium‐based catalysis in single electron transfer (SET) steps has evolved into a versatile approach for the synthesis of fine chemicals and first attempts have recently been made to enhance its sustainability by merging it with photo‐redox (PR) catalysis. Here, we explore the photochemical principles of all‐Ti‐based SET‐PR‐catalysis, i.e. in the absence of a precious metal PR‐co‐catalyst. By combining time‐resolved emission with ultraviolet‐pump/mid‐infrared‐probe (UV/MIR) spectroscopy on femtosecond‐to‐microsecond time scales we quantify the dynamics of the critical events of entry into the catalytic cycle; namely, the singlet‐triplet interconversion of the do‐it‐all titanocene(IV) PR‐catalyst and its one‐electron reduction by a sacrificial amine electron donor. The results highlight the importance of the PR‐catalyst's singlet‐triplet gap as a design guide for future improvements.

The shear force from a gold or a graphite sample acting on an approaching near-field optical probe is studied in detail. The adiabatic and dissipative contributions to the force are clearly distinguished by monitoring the amplitude as well as the phase of the tip vibration when the tip approaches the surfaces. We also take into account that not only the damping and the resonance frequency but also the mass of the system changes when the tip approaches the surface. The relative strength of the contributions to the force varies differently but characteristically with the distance of the two samples, starting at a much larger distance in the case of graphite. The adiabatic contribution is larger in the case of the gold sample. Measurements at various temperatures are performed using the gold sample, showing a dependence of the shear force on the varying conditions.

SummaryThe shear force between a gold and a graphite sample and an approaching near-field optical probe using tuning fork detection is studied in detail. The adiabatic and dissipative contributions are clearly distinguished by monitoring the amplitude as well as the phase of the tip vibration when approaching the surfaces. Their relative strengths vary differently but characteristically with the distance. The interaction starts in case of graphite at a much larger distance. The adiabatic contribution is larger in the case of gold, whereas graphite shows mostly dissipative interaction. Measurements at various temperatures are performed using a gold sample, showing a dependence of the shear force on the temperature.