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One of the most detrimental loss mechanisms in Luminescent Solar Concentrators (LSCs) is reabsorption of emitted light from the luminophore. Silicon Nanocrystals (SiNCs) offer a solution due to the high apparent Stokes shift, but the poor absorption properties limit their performance as LSC luminophores. Coupling an organic dye to SiNCs represents a smart approach to obtain sensitization of SiNC luminescence by the organic dyes, thus, resulting in tunable and improved optical properties of LSCs. In particular, 9,10-diphenylanthracene was employed as a UV sensitizer for SiNCs in order to produce LSCs with an aesthetic appearance suitable to smart window application and optical efficiency as high as 4.25%. In addition, the role of the energy transfer process on LSC performance was elucidated by a thorough optical and photovoltaic characterization.

Silicon nanocrystals (SiNCs) synthesized by plasma-induced or high temperature processes (e.g., thermal disproportionation of hydrogen silsesquioxane at T > 1100 °C) display bright (photoluminescence quantum yield up to 70%) and long-lived luminescence (hundreds of μs), which can be tuned from green to red and near-infra-red spectral regions according to nanocrystal dimensions. The present review focuses on the parameters affecting the optical properties of these SiNCs, namely size, shape, surface, degree of crystallinity, and on a method to increase their brightness by functionalising SiNCs with dyes to build up a light-harvesting antenna. The final discussion presents some of the most recent examples of applications, which take advantage of the luminescence properties of SiNCs: energy conversion devices, sensors, and bioimaging probes.

Two molybdenum(VI) complexes bearing a C3 symmetrical amino tris-tert-butylphenolate ligand have proved to be air- and water-tolerant catalysts that efficiently catalyse, in high yields and selectivity, the oxidation of sulfides, olefins and halides. In particular high turnover frequencies and turnover numbers (TOF and TON) have been obtained for the cyclooctene epoxidation (catalyst loading down to 0.05%, TONs up to 88,000 and TOFs up to 7500 h−1)

Within the developing interface between free radicals and supramolecular chemistry, nitroxides play a special role because they are stable and easy to functionalize. This Focus Review summarizes recent progress in the design and synthesis of paramagnetic host‐guest complexes characterized by the presence of a nitroxide label covalently linked to the organic macrocycle. Examples include the synthesis of open‐shell, mechanically interlocked molecules (MIMs), such as rotaxanes, in which the dumbbell, the wheel, or both are tagged with nitroxide radicals, and how electron spin resonance (ESR) spectroscopy methods have been used for detecting and identifying the assemblies and for clarifying their structure and properties.

Photoluminescence of silicon nanocrystals (SiNCs) in the presence of a series of quinone electron acceptors and ferrocene electron donors is quenched by oxidative and reductive electron transfer dynamic processes, respectively. The rate of these processes is investigated as a function of (a) the thermodynamic driving force of the reaction, by changing the reduction potentials of the acceptor or donor molecules, (b) the dimension of SiNCs (diameter = 3.2 or 5.0 nm), (c) the surface capping layer on SiNCs (dodecyl or ethylbenzene groups), and (d) the solvent polarity (toluene vs dichloromethane). The results were interpreted within the classical Marcus theory, enabling us to estimate the position of the valence and conduction bands, as well as the reorganization energy (particularly small, as expected for quantum dots) and electronic transmission coefficients. The last parameter is in the range 10 −5 −10 −6 , demonstrating the nonadiabaticity of the process, and it decreases upon increasing the SiNC dimensions: this result is in line with a larger number of excitons generated in the inner silicon core for larger SiNCs and thus resulting in a lower electronic coupling with the quencher molecules.

Fluorinated monolayers on the surface of gold NPs display enhanced binding affinities for hydrophobic fluorinated compounds with respect to hydrogenated ones.

In vivo studies demonstrated tumor accumulation of luminescent SiNCs, 48 hours clearance and a 3-fold improvement of signal-to-noise ratio in time-gated imaging compared to steady-state acquisition, demonstrating their potentiality for luminescence guided surgery.