Metal-free stereoselective additions of activated nucleophiles to β-nitrostyrenes were investigated under continuousflow conditions in microreactors, in the presence of a chiral bifunctional catalyst. Optimization of the experimental setup gave excellent enantioselectivities (up to 85% e.e.) and higher productivities if compared to the flask syntheses. The potential of this flow chemistry approach was demonstrated by the successful synthesis of an advanced intermediate for the preparation of the GABA B receptor agonist Baclofen.

We report the use of microfluidics to functionalize suspended reduced graphene oxide flakes through the addition of aryl radical, generated in situ by reaction between aryl amines and isopentyl nitrite. Microfluidic enabled a tight control of temperature, reaction times, and stoichiometric ratios, making it possible to tune the growth of oligomers on the surface of the flakes, which in turn affects the interactions of the functional material with the surrounding environment. The results suggest that shear stress phenomena within the reactor may play a role in the chemistry of graphene materials by providing a constant driving force toward exfoliation of the layered structures. Scale-up of the functionalization process is also reported along with the grafting of dyes based on squaric acid cores. Photophysical characterization of the dye-modified flakes proves that the microfluidic approach is a viable method toward the development of new materials with tailored properties.

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The synthesis of a new class of robust squaraine dyes, colloquially named 1,2-hemisquarimines (1,2-HSQiMs), through the microwave-assisted condensation of aniline derivatives with the 1,2-squaraine core is reported. In CH3CN, 1,2-HSQiMs show a broad absorption band with a high extinction coefficient and a maximum at around λ=530 nm, as well as an emission band centered at about λ=574 nm, that are pH dependent. Protonation of the imine nitrogen causes a redshift of both absorption and emission maxima, with a concomitant increase in the lifetime of the emitting excited state. Encapsulation of the chromophore into a cucurbit[7]uril host revealed fluorescence enhancement and increased photostability in water. The redox characteristics of 1,2-HSQiMs indicate that charge injection into TiO2 is possible; this opens up promising perspectives for their use as photosensitizers for solar energy conversion.

Through ac ycloaddition reaction, fullerene( C 60 )w as derivatized with an ovel organic compound 5-(benzo [b]thiophen-3-yl)pyridine-3-carbaldehyde to form the processable and stable 3-(benzo [b]thiophene-3yl)-5-fullero-1-methylpyrrolidinepyridine (BTFP) compound. BTFP exhibits close similarities to phenyl-C61-butyric-acid-methyl-ester (PCBM)i nt erms of first reduction potentialv alues (À0.62 and À0.61 Vv s. Ag/AgCl, for BTFP and PCBM, respectively)a nd lowest occupied molecular orbital (LUMO) energy level values (3.93 eV in both cases). In chloroform, BTFP exhibits ab athochromic shift in the l max of BTFP (l max, BTFP = 290 nm and l max, PCBM = 260 nm), owing to the graftedb enzo [b]thiophene-3-yl)pyridinem oiety.D espite the similarityi nL UMO (3.93 eV) energy values, BTFP and PCBM differ in their luminescence-quenching ability.T he bathochromic shift in the l max of BTFP (relative to PCMB) is likely to contribute to improved light absorption of as uitable donor for photovoltaic applications.The uniquenesso fc losed-cage, nearly spherical C 60 and related fullerenem olecules has attracted considerable attention. The icosahedrals ymmetry [1] and numerousp ossibilities of functionalizationa llow the modulation of their optoelectronic properties, [2] leading to unabated interest in these intriguing carbon allotropes. The chemistry of fullerenes is that of electron-poor olefins, with sp 2 carbon atoms constrained into apyramidalized geometry.M ultiple double bonds are available on the carbon backbone, making multiple functionalization [3] an interesting route towards new functional materials.This has led to avariety of novel compoundsw ithf inely tunable features thath ave found applicationsa sc atalysts [4] and antioxidants, [5] as well as in sensors [6] and solar cells. [2a, 7] The functionalization of fullerenes does not only modifyt heir properties, but converts them into more processable forms, as pristine C 60 is only sparselys oluble in most solvents, making it intractable. Indeed, the quest for soluble fullerenes was (and still is) one of the main driving forces in the field of covalent modification of carbon nanostructures. Phenyl-C61-butyric-acid-methyl-ester (PCBM), af ullerened erivative, is as olution-processable n-type organic semiconductor,w hich is commonly blended with ptype conjugated polymers to make photovoltaic( PV) cells. However,o wing to the dependence of PV properties on frontier orbital energy levels of donor and acceptors, the application of PCBM to all donorp olymers irrespective of their optoelectronic properties leads to untrue PV properties. For instance,r eports by Susarova et al. [8] and Kästnere tal. [9] compared the PV responses of as et of polymers with PCBM and other functionalized fullerenes and observed that PCBM gave just moderate efficiencies in combination with the polymers, whereas the best PV performances were obtained with ab lend of each polymerw ith specific fullerened erivatives possessing better-suiting molecularstructures. Herein, we describe afulleropyrrolid...

In the attempt to improve optical limiting of cw lasers by exploiting the thermo-optic effect exhibited by gold nanostructures, we investigated two coupled systems consisting of either gold nanoparticles (AuNPs) or gold-silica coreshell (AuNSs), both functionalized with a thiolated-fulleropyrrolidine (C60Py). We measured the optical limiting behavior under cw illumination at 514 and 647 nm, resonant with the surface plasmon resonance at around 520 of AuNPs and at 650 nm of AuNSs, respectively. Temporal response analysis shows the variation of transmitted irradiance in a 300 milliseconds time interval, corresponding to the blinking time of the human eye. Comparing the present results we those previously obtained for AuNPs 1 we demonstrate an improvement of the response of functionalized nanoparticles (AuNPsC60Py) with respect to bare AuNPs.