Directionality of electron transfer and long-lived charge separation are of key importance for efficient photocatalytic water splitting. Knowledge of the processes that follow photoexcitation is essential for the optimization of supramolecular assembly designs in order to improve the efficiency of photocatalytic hydrogen generation. Photoinduced intramolecular electron transfer processes within the hydrogen-evolving photocatalyst [Ru(bpy) 2 (tpy)Pd(CH 3 CN)Cl] 2+ (RuPd; bpy = bipyridine, tpy = 2,2′:5′,2″-terpyridine) have been studied by resonance Raman, femtosecond transient absorption, and time-resolved photoluminescence spectroscopies. Comparison of the photophysical properties of RuPd with those of the mononuclear precursor [(bpy) 2 Ru(tpy)] 2+ (Ru) enables establishment of a photophysical model ranging from the femtosecond to the submicrosecond domain. Optical excitation of Ru and RuPd populates both bpy-and tpy-based 1 MLCT (metal-to-ligand charge transfer) singlet states, from where intersystem crossing (ISC) into corresponding 3 MLCT triplet states occurs. Electron density localized on the peripheral bpy ligands can subsequently flow to the tpy bridging ligand by interligand electron transfer, which process occurs with a time constant of 32.5 (±1.5) ps for RuPd. Not all electron density undergoes this process, most likely due to a competing loss channel on the bpy ligand caused by vibrational relaxation occurring at a time scale of 9.1 (±0.4) ps. The relaxed 3 MLCT bpy and 3 MLCT tpy states have excited state lifetimes of 400 (±1) ns and 88 (±1) ns, respectively. Electron transfer from the tpy ligand to Pd may take place on a ∼100 ns time scale, but it is also possible that the final relaxed excited state is delocalized over the tpy ligand and the Pd center. The insight that optical excitation populates both the peripheral bpy ligands and the bridging tpy ligand, and that part of the electron density subsequently flows from the former to the latter, is important for the realization of efficient photocatalytic hydrogen generation. The next step is to make the interligand electron transfer process faster, by functionalizing the peripheral ligands with electron-donating moieties, and adapting the nature of the bridging ligand and the catalytic metal center.

The oxidation of alkenes, alkanes, and alcohols with H 2 O 2 is catalyzed efficiently using an in situ prepared catalyst comprised of a Mn II salt and pyridine-2-carboxylic acid (PCA) together with a ketone in a wide range of solvents. The mechanism by which these reactions proceed is elucidated, with a particular focus on the role played by each reaction component: i.e., ketone, PCA, Mn II salt, solvent, etc. It is shown that the equilibrium between the ketone cocatalysts, in particular butanedione, and H 2 O 2 is central to the catalytic activity observed and that a gem-hydroxyl-hydroperoxy species is responsible for generating the active form of the manganese catalyst. Furthermore, the oxidation of the ketone to a carboxylic acid is shown to antecede the onset of substrate conversion. Indeed, addition of acetic acid either prior to or after addition of H 2 O 2 eliminates a lag period observed at low catalyst loading. Carboxylic acids are shown to affect both the activity of the catalyst and the formation of the gem-hydroxyl-hydroperoxy species. The molecular nature of the catalyst itself is explored through the effect of variation of Mn II and PCA concentration, with the data indicating that a Mn II :PCA ratio of 1:2 is necessary for activity. A remarkable feature of the catalytic system is that the apparent order in substrate is 0, indicating that the formation of highly reactive manganese species is rate limiting.

This manuscript describes the production of Molecularly Imprinted Polymer nanoparticles (nanoMIPs) for the cardiac biomarkers heart-fatty acid binding protein (H-FABP) and ST2 by solid-phase synthesis, and their use as synthetic antibodies in a multiplexed sensing platform. Analysis by Surface Plasmon Resonance (SPR) shows that the affinity of the nanoMIPs is similar to that of commercially available antibodies. The particles are coated onto the surface of thermocouples and inserted into 3D-printed flow cells of different multiplexed designs. We demonstrate it is possible to selectively detect both cardiac biomarkers within the physiologically relevant range. Furthermore, the developed sensor platform is the first example of a multiplex format of this thermal analysis technique which enables simultaneous measurements of two different compounds with minimal cross selectivity. The format where three thermocouples are positioned in parallel exhibits the highest sensitivity, which is explained by modelling the heat flow distribution within the flow cell. This design is used in further experiments and proof-of-application of the sensor platform is provided by measuring spiked fetal bovine serum samples. Due to the high selectivity, short measurement time, and low-cost of this array format, it provides an interesting alternative to traditional immunoassays. The use of nanoMIPs enables a multi-marker strategy, which has the potential to contribute to sustainable healthcare by improving reliability of cardiac biomarker testing.

An efficient and simple method for selective oxidation of secondary alcohols and oxidation of alkanes to ketones is reported. An in situ prepared catalyst is employed based on manganese(II) salts, pyridine-2-carboxylic acid, and butanedione, which provides good-to-excellent conversions and yields with high turnover numbers (up to 10 000) with H2 O2 as oxidant at ambient temperatures. In substrates bearing multiple alcohol groups, secondary alcohols are converted to ketones selectively and, in general, benzyl C-H oxidation proceeds in preference to aliphatic C-H oxidation.

The effect of the catalytic moiety on the early-time photodynamics of Ru/M (M=Pt or Pd) bimetallic photocatalysts is studied by ultrafast transient absorption spectroscopy. In comparison to the Ru/Pd photocatalyst described earlier, the Ru/Pt analogue shows complex excited-state dynamics with three distinct kinetic components ranging from sub-ps to 10(2)  ps, requiring a more sophisticated photophysical model than that developed earlier for the Ru/Pd complex. In the Pu/Pt photocatalyst, an additional lower-lying excited state is proposed to quench the hot higher-lying triplet metal-to-ligand charge-transfer states. Furthermore, a strong excitation wavelength dependence on the population of excited states is observed for both the Ru/Pt and Ru/Pd complexes, indicating a non-equilibrated distribution even on the 10(2)  ps timescale. These insights shed light on the significant impact of the catalytic moiety on the fundamental early-time photophysics of Ru-based photocatalysts.