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Gold nanoparticles (AuNPs) were functionalized by ruthenium porphyrins through a sulfur/gold covalent bond using a three-steps reaction. The catalyst was characterized by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) in order to control the binding of ruthenium porphyrin on AuNPs’ surface. The catalyst was tested and compared with an analog system not bound to AuNPs in the oligomerization reaction using 1-phenylacetylene as the substrate.

In this research, we investigated the second-order nonlinear optical (NLO) properties of multicomponent hybrid materials formed by meso-tetraphenylporphyrin P (both as free base and ZnII complex), carrying in 2 or 2,12 β-pyrrolic position an electron donor ferrocene (Fc), and/or an electron acceptor fullerene (C60) moiety, connected to the porphyrin core via an ethynyl or an ethynylphenyl spacer. We measured the NLO response by the electric-field-induced second-harmonic generation (EFISH) technique in CH2Cl2 solution with a 1907 nm incident wavelength, recording for all the investigated compounds unexpected negative values of μβ1907. Since density functional theory (DFT) calculations evidenced for P-Fc dyads almost null ground state dipole moments and very low values for P-C60 dyads and Fc-P-C60 triads, our EFISH results suggested a significant contribution to γEFISH of the purely electronic cubic term γ(−2ω, ω, ω, 0), which prevails on the quadratic dipolar orientational one μβ(−2ω, ω, ω)/5kT, as confirmed by computational evidence.

A novel family of nanocarbon‐based materials was designed, synthesized, and probed within the context of charge‐transfer cascades. We integrated electron‐donating ferrocenes with light‐harvesting/electron‐donating (metallo)porphyrins and electron‐accepting graphene nanoplates (GNP) into multicomponent conjugates. To control the rate of charge flow between the individual building blocks, we bridged them via oligo‐p‐phenyleneethynylenes of variable lengths by β‐linkages and the Prato–Maggini reaction. With steady‐state absorption, fluorescence, Raman, and XPS measurements we realized the basic physico‐chemical characterization of the photo‐ and redox‐active components and the multicomponent conjugates. Going beyond this, we performed transient absorption measurements and corroborated by single wavelength and target analyses that the selective (metallo)porphyrin photoexcitation triggers a cascade of charge transfer events, that is, charge separation, charge shift, and charge recombination, to enable the directed charge flow. The net result is a few nanosecond‐lived charge‐separated state featuring a GNP‐delocalized electron and a one‐electron oxidized ferrocenium., Nanocarbon‐based charge‐transfer cascades were designed by integrating electron‐donating ferrocenes with light‐harvesting/electron‐donating (metallo)porphyrins and electron‐accepting graphene nanoplates. The building blocks were bridged through oligo‐p‐phenyleneethynylenes. Physico‐chemical characterization of the multicomponent conjugates revealed a selective photoexcitation triggered cascade of charge transfer events.

The synthesis of CdSe quantum dots (QDs) from a single source precursor is a known way to form a nanocomposite by its thermal decomposition. Recently, some of them have been used to grow QDs by direct laser patterning. Here, the authors report the study of the formation of the CdSe QDs starting from the decomposition of the 2-(N,N-dimethylamino)ethylselenolate of cadmium dispersed in a polymethylmethacrylate film induced both by heating and laser patterning. The formation of the CdSe QDs under annealing at 150 °C is studied as a function of the precursor concentration and molar ratio with respect to two different QD ligands such as oleic acid and oleylamine. The photoluminescent spectra of the formed nanocomposite show that the oleic acid induces the formation of the direct bandgap, while oleylamine shows only a broadband emission. The laser patterning of the film was carried out with a UV laser (355 nm) with a pulse frequency of 40 kHz and a fluence of 1.06 J/cm2. The resulting patterned areas were characterized by a fluorescence microscope showing the formation of a photoluminescence path only when the ligands were present, suggesting the formation of the functional (photoluminescent) QDs.The synthesis of CdSe quantum dots (QDs) from a single source precursor is a known way to form a nanocomposite by its thermal decomposition. Recently, some of them have been used to grow QDs by direct laser patterning. Here, the authors report the study of the formation of the CdSe QDs starting from the decomposition of the 2-(N,N-dimethylamino)ethylselenolate of cadmium dispersed in a polymethylmethacrylate film induced both by heating and laser patterning. The formation of the CdSe QDs under annealing at 150 °C is studied as a function of the precursor concentration and molar ratio with respect to two different QD ligands such as oleic acid and oleylamine. The photoluminescent spectra of the formed nanocomposite show that the oleic acid induces the formation of the direct bandgap, while oleylamine shows only a broadband emission. The laser patterning of the film was carried out with a UV laser (355 nm) with a pulse frequency of 40 kHz and a fluence of 1.06 J/cm2. The resulting patterned areas were chara...

We probed a series of multicomponent electron donor2-donor1-acceptor1 conjugates both experimentally and computationally. The conjugates are based on the light harvester and primary electron-donor zinc-porphyrin (ZnP, donor1) to whose β positions a secondary electron-donor ferrocene (Fc, donor2) and the primary electron-acceptor C60-fullerene (C60, acceptor1) are attached. Linking all of them via p-phenylene-acetylene/acetylene bridges of different lengths to gain full control over shuttling electrons and holes between C60, ZnP, and Fc is novel. Different charge-separation, charge-transfer, and charge-recombination routes have been demonstrated, both by transient absorption spectroscopy measurements on the femto, pico-, nano-, and microsecond time scales and by multiwavelength and target analyses. The molecular wire-like nature of the p-phenylene-acetylene bridges as a function of C60-ZnP and ZnP-Fc distances is decisive in the context of generating distant and long-lived C60•--ZnP-Fc•+ charge-separated states. For the first time, we confirm the presence of two adjacent charge-transfer states, a C60-ZnP•--Fc•+ intermediate in addition to C60•--ZnP•+-Fc, en route to the distant C60•--ZnP-Fc•+ charge-separated state. Our studies demonstrate how the interplay of changes in the reorganization energy and the damping factor of the molecular bridges, in addition to variation in the solvent polarity, affect the outcome of the charge-transfer and corresponding rate constants. The different regions of the Marcus parabola are highly relevant in this matter: The charge recombination of, for example, the adjacent C60•--ZnP•+-Fc charge-separated state is located in the inverted region, while that of the distant C60•--ZnP-Fc•+ charge-separated state lies in the normal region. Here, the larger reorganization energy of Fc relative to ZnP makes the difference.

The Poster is realised within the Research Night 2019 (September 27 2019 Frascati) Nanotechnologies and photonics are a new field of research that is gradually becoming part of our daily life even though we are not always aware of them. In the presentation to the public we want to show in a simple and intuitive way these two concepts and how they decline in everyday reality. &nbsp

Carbon spheres of nanometric dimension are known since the first studies on the synthesis of fullerenes. Their shape originates from the curvature of a carbon sheet similar to fullerenes, but with numerous graphitic rings that regulate the inside structure and the formation of open edges at the surface. This paper focuses on the structural and electronic characterization of carbon spheres obtained from a chemical vapor deposition synthesis process. Two different sets of samples are analyzed in detail, in particular, electron microscopies and Raman spectroscopy help understanding the morphology and the graphitic-sp2 arrangement of the carbon atoms in the architectures. In addition, the iron catalyst used during the reaction process confers the carbon spheres a ferromagnetic response at room temperature. Therefore, both the structural properties of the samples and the active contribution of iron mark the difference in the measured photoresponse as well as in the electrochemical behavior. The X-ray photoelectron spectroscopy study addresses these points by giving information on the composition and the iron chemical state in the assembly. The collected results underline the advantages offered by this nanomaterial for sustainable applications.

Herein, we report the synthesis of several magnetic carbon structures starting from spheres (CSs) to more elongated structures to get tubes and fibers by customizing chemical vapour deposition parameters. These CSs-based products, ranging from nano-to micro-size, were investigated by morphological point of view using scanning electron microscopy, energy dispersive x-ray spectroscopy, and Raman spectroscopy. These carbon structures were combined with screen-printed electrodes highlighting their electrochemical effectiveness towards the detection of several species, i.e. ferricyanide, ascorbic acid, dopamine, cysteine, serotonin, and NADH. The presence of iron nuclei within the carbonaceous lattices, besides having improved the electrochemical performances at the printed electrodes, might confer these CSs-based structures a future application in the field of remediation/sensing. Herein, some preliminary applications were provided showing that these materials can be easily employed to collect species and, successively, coupled with printed electrochemical sensors.

Carbon spheres of nanometric dimension are known since the first studies on the synthesis of fullerenes. Their shape originates from the curvature of a carbon sheet similar to fullerenes, but with numerous graphitic rings that regulate the inside structure and the formation of open edges at the surface. This paper focuses on the structural and electronic characterization of carbon spheres obtained from a targeted chemical vapor deposition synthesis process. Two different set of samples are analyzed in detail, in particular, the electron microscopies and Raman spectroscopy help understanding the morphology and the graphitic-sp2 arrangement of the carbon atoms in the architectures. In addition, the iron catalyst used during the reaction process confers the carbon spheres a ferromagnetic response at room temperature. Therefore, both the structural properties of the samples and the active contribution of iron mark the difference in the measured photoresponse as well as in the electrochemical behavior. The X-ray photoelectron spectroscopy study addresses these points by giving information on the composition and the iron chemical state in the assembly. The collected results underline the advantages offered by this synthesis route and the properties of the carbon spheres as active nanomaterial for sustainable applications.

Ruthenium(II) 5-(4[Formula: see text]-sulfanylmethylphenyl)-10,15,20-triphenylporphyrin (Ru-TPP-SH) and manganese(III) 5-(4[Formula: see text]-sulfanylmethylphenyl)-10,15,20-triphenylporphyrin (Mn-TPP-SH) were synthesized, spectroscopically characterized and drop casted to modify screen-printed electrodes (SPEs). The modified SPEs were then tested against the redox target [Fe(CN)6][Formula: see text] in comparison with the bare SPE and SPE modified with the free porphyrin. The best performing one, [Formula: see text]. Mn-TPP-SH was used for the electrochemical detection of 1,4–benzoquinone, serotonin, caffeic and ascorbic acids, the latter also in association with uric acid, showing good electrocatalytic properties. The tunability of the metal-TPP-SH through the choice of the coordinating metal, the drop casting conditions and possible further functionalization make this type of porphyrin a good candidate for further developments of porphyrin-modified SPEs.

Meso-tetraphenylporphyrin connected with a ferrocene molecule in the beta-position of the macrocycle through a triple carbon@carbon bond has been bound to carbon spheres using the Prato@Maggini reaction. The ethynyl or/and phenylene ethynylene subunits were chosen as a linking bridge to give a high conjugation degree between the donor (i. e., ferrocene), the photoactive compound (i. e., porphyrin), and the acceptor (i. e., carbon spheres). The molecular bridges have been directly linked to the beta-pyrrole positions of the porphyrin ring, generating a new example of a long-range donor@acceptor system. Steady-state fluorescence studies together with Raman and XPS measurements helped understanding the chemical and physical properties of the porphyrin ring in the new adduct. The spectroscopic characteristics were also compared with those obtained from a similar compound bearing fullerene instead of carbon spheres. &nbsp

The 2,12 pyrrole positions of meso-tetraphenylporphyrin were functionalized through triple carbon–carbon bonds by C60 and ferrocene giving new electron donor–acceptor triads which have been characterized and studied by photophysical methods. The fluorescence spectra of the new compounds have been compared to those previously reported for similar compounds giving as a result an increase of the quantum efficiency based on the larger separation of fullerene from the porphyrin ring. On the contrary the efficiency decreases with the presence of a phenylene spacer between ferrocene and the macrocycle.