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Un nuovo sistema donatore-accettore bisaddotto bitiofene fulleropirrolidi na (bis-C60Bi) è stato elettropolimerizzato su ITO/PET(ossido di Indio-Sta gno)/PoliEtilene Tereftalato per cronoamperometria. E’ stato applicato un potenziale anodico di 1.5V alla soluzione di monomero per un certo tempo ¿QR DOO¶RWWHQLPHQWR GL XQ ¿OP VRWWLOH SROLPHULFR VXO VXEVWUDWR &DUDWWHUL]]D zioni XPS, UV-vis hanno confermato la presenza del polimero sull’elettrodo. ...

The synthesis of innovative catalysts based on different carbon nanoforms (CNFs), namely fullerene C60 and carbon nanotubes (CNTs), and their application in Suzuki and Heck C-C coupling reactions, constitutes the common thread of the first part (Chapter 1 and 2) of this thesis. C60 and CNTs were functionalized with ionic liquids (ILs) and poly-amidoamine (PAMAM) dendrimers, respectively, and used as supports for palladium nanoparticles (PdNPs). Moreover, additional supported catalytic systems based on one of the synthesized C60-IL hybrids were prepared and successfully employed in the title coupling reactions. The final part (Chapter 3) of the thesis deals on the microwave-mediated synthesis optimization of some fullerene-based acceptors species for organic photovoltaics (OPV). In such a way, the main C60- and C70-based acceptor derivatives for organic solar cells, such as PCBM, DPM6, BHN and ICBA, were obtained in higher yields and shorter reaction times with respect to the data reported in literature. These findings represent a step forward toward the wide production of cheaper organic solar cells as a consequence of the cost abatement of the acceptors given by higher yields, lower waste production, and reduced reaction time which means a strong energy saving.

Carbon nanotubes have been covalently functionalized with catechol moieties through the formation of the corresponding aryl radicals obtained by reacting 4-aminocatechol with isoamyl nitrite. The functionalized multiwalled carbon nanotubes have been in turn used to immobilize Pd(II) ions on its surface forming catechol-Pd complexes, which were reduced to Pd nanoparticles (NPs). The so-obtained hybrid material has been characterized by means of thermogravimetric analysis coupled with differential scanning calorimetry (TGA-DSC), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). This latter technique allowed to estimate the nanoparticle size (5.7 +/- 2.8 nm) whereas a palladium loading of 20.3 wt % has been found by inductively coupled plasma optical emission spectroscopy (ICP-OES). The carbon nanotube-catechol-Pd hybrid was used as catalyst in two C-C coupling reactions, namely Suzuki and Heck reactions, resulting recyclable for at least 9 times in the latter process. During the reuse Pd nanoparticles increase their dimension to 19.3 +/- 11.7 nm.

The increased awareness of the catastrophic consequences caused by the accumulation of greenhouse gases into the atmosphere has generated a large mobilization aimed at CO2 mitigation. Herein, in the spirit of the transformation of a waste as CO2 into value added products, we propose an efficient preparation of two different hybrid systems based on aluminum chloride tetrastyrylporphyrin (TSP-Al-Cl) and 1,4-butanediyl-3,3′-bis-1-vinylimidazolium dibromide copolymerized in the presence (MWCNT-TSP-AlCl-imi) and in absence (TSP-AlCl-imi) of multi-walled carbon nanotubes (MWCNTs) for the CO2 utilization in the synthesis of cyclic carbonates. The so-prepared materials have been thoroughly characterized by means of several spectroscopic and analytical techniques. The MWCNT-TSP-AlCl-imi heterogenous catalyst enabled the highly efficient chemical transformation of CO2 and epoxides into cyclic carbonates with high turnover number (TON) and frequency (TOF) values at low temperature down to 30 °C in solvent-free conditions. MWCNT-TSP-AlCl-imi proved to be a very stable and reusable heterogeneous catalyst in consecutive cycles without the need of any reactivation procedure and no leaching phenomena. Furthermore, the optimal morphology of MWCNT-TSP-AlCl-imi, with the crosslinked polymer uniformly distributed onto MWCNTs backbone, resulted in a more active catalyst with a TON double than the unsupported one. The enhanced activity of MWCNT-TSP-AlCl-imi can be ascribed to its higher surface area that permits fully accessible catalytic sites. Interestingly, MWCNT-TSP-AlCl-imi also showed a catalytic activity comparable to a reference homogeneous catalytic system, proving that synergism occurred between the metal centers and the nucleophilic sites due to their close proximity.

The hydrolysis of 3-ammoniumpropylbis(catecholato)silicate 1, giving two different silica-based materials containing different amounts of tris(catecholato)silicate, is reported. The latter species can be formed through an attack of catechol to the silicon atom in the pentacoordinate complex, in which the silicon-carbon bond is further activated toward electrophilic proton cleavage. The Knoevenagel reaction was used as a probe in order to test the availability of functional groups on the surface of such materials.

The aim of this Perspective is to start a discussion about the real usefulness of more or less sophisticated catalytic systems for the Knoevenagel reaction with malononitrile, a reaction that can take place under mild conditions without the need of a catalyst. From a sustainable viewpoint the questions are: Is it useful to increase the rate of a reaction that already occurs under mild conditions? Is it useful to spend resources and time in designing, characterizing and realizing complex catalytic systems for such reaction? Does it make sense to carry out the reaction under conditions such as to have a slower reaction rate and therefore to find a catalyst that is able to increase it?

Two heterogeneous catalysts were prepared with the aim of following the promising path of CO2 fixation into epoxides. The synthetic procedure involves a radical copolymerization of an octavinylsilsesquioxane as inorganic core building block and tetrastyrylporphyrin aluminum chloride monomer (TSP-AlCl) in presence (POSS-TSP-AlCl-imiBr) or in absence (POSS-TSP-AlCl) of a bis-vinylimidazolium bromide salt (bis-imiBr), in order to investigate if the bifunctional heterogeneous material can display better catalytic performance than the separate species. All the solids were fully characterized and tested in the synthesis of cyclic carbonates starting from CO2 and several epoxides. The synergic cooperation of the two co-catalytic species (Lewis acid/imiBr) was observed. POSS-TSP-AlCl-imiBr showed to be a recyclable material with an excellent activity and TON and TOF values up to 16,000 and 5000, respectively. These excellent results, even under mild reaction and solvent-free conditions, were attributed to a twofold effect: the proximity between the two active sites due to the direct covalent bond between the porphyrin and the imidazolium component and the increasing local concentration of active sites effect that is obtained by functionalizing the silica cage at all its vertices.

Three different carbon nanoforms (CNFs), single-walled and multi-walled carbon nanotubes (SWCNTs, MWCNTs) and carbon nanohorns (CNHs), have been used as supports for the direct polymerization of variable amounts of a bis-vinylimidazolium salt. Transmission electron microscopy confirmed that all CNFs act as templates on the growth of the polymeric network, which perfectly covers the nanocarbons forming a cylindrical (SWCNTs, MWCNTs) or spherical (CNHs) coating. The stability of these hybrid materials was investigated in the conversion of CO2 into cyclic carbonate under high temperature and CO2 pressure. Compared with the homopolymerized monomer, nanotube-based materials display an improved catalytic activity. Beside the low catalytic loading (0.05–0.09 mol%) and the absence of Lewis acid co-catalysts, all the materials showed high TON values (up to 1154 for epichlorohydrin with SW-1:2). Interestingly, despite the loss of part of the polymeric coating for crumbling or peeling, the activity increases upon recycling of the materials, and this behaviour was ascribed to their change in morphology, which led to materials with higher surface areas and with more accessible catalytic sites. Transmission electron microscopy analysis, along with different experiments, have been carried out in order to elucidate these findings.

Supported imidazolium modified polyhedral oligomeric silsesquioxanes (POSS) on SBA-15 have been used as platform for Pd(II) species. The so-obtained material was firstly characterized by means of TGA, solid state NMR, TEM, XPS, SAXS, porosimetry and ICP-OES and it was successfully tested as pre-catalyst in C−C cross couplings, namely Suzuki-Miyaura and Heck reactions. In both cases, the solid proved to be highly efficient and easily recoverable from the reaction mixture. The recyclability was verified for up to seven cycles without showing any activity decrease. Interestingly, only Pd(II) was detected in the reused catalyst in the Heck reaction. Therefore, the versatility of the material was investigated by using various aryl halides. Our palladium nanocomposite was able to promote both Suzuki and Heck reactions down to 0.0007 mol% showing outstanding turnover frequency (TOF) values of 114,286 and 32,381 h −1 , respectively. Comparison with the palladium catalyst on SiO 2 -POSS-imidazolium support showed interesting differences in terms of stabilization of Pd species and recyclability. The excellent outcome of the reactions could be ascribed to the textural properties of the SBA-15 support and the presence of the imidazolium-POSS nanocage within the pores of SBA-15, that worked as a sort of nanoreactor. (Figure presented.).

A straightforward and economic procedure has been developed for the synthesis of a new polydopamine-like silica-based material that has been obtained by oxidation of catechol with KIO4 followed by reaction with 3-aminopropyltrimethoxysilane. All techniques adopted for characterization showed that the obtained material is rich in different functional groups and the morphological analyses revealed dimensions in the nanometric range. The hybrid material has been characterized by several techniques showing its polydopamine-like nature, and preliminary observations for dye adsorption have been reported., University of Palermo PRIN2017- 2017YJMPZN

Multiwalled carbon nanotubes (MWCNTs) were easily and efficiently functionalised with highly cross-linked polyamines. The radical polymerisation of two bis-vinylimidazolium salts in the presence of pristine MWCNTs and azobisisobutyronitrile (AIBN) as a radical initiator led to the formation of materials with a high functionalisation degree. The subsequent treatment with sodium borohydride gave rise to the reduction of imidazolium moieties with the concomitant formation of secondary and tertiary amino groups. The obtained materials were characterised by thermogravimetric analysis (TGA), elemental analysis, solid state 13C-NMR, Fourier-transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), potentiometric titration, and temperature programmed desorption of carbon dioxide (CO2-TPD). One of the prepared materials was tested as a heterogeneous base catalyst in C-C bond forming reactions such as the Knoevenagel condensation and Henry reaction. Furthermore, two examples concerning a sequential one-pot approach involving two consecutive reactions, namely Knoevenagel and Michael reactions, were reported. This journal is

A new class of copolymers containing oligothiophene moieties with different lengths and fullerene units have been designed and prepared by an easy and inexpensive one-step synthetic approach. The incorporation of small quantities of these copolymers into bulk heterojunction (BHJ) solar cells with donor regioregular polythiophene (P3HT) and an acceptor fullerene derivate (PCBM) results in good control of the phase separation process without further affecting the BHJ optoelectronic properties. Indeed, under thermal annealing these copolymers allow the modulation of the growth of domains whose size depends on the length of the copolymer repetitive units. Domain size on the same length scale as the P3HT exciton diffusion length with a good continuity between the electrodes gives efficient exciton dissociation and charge mobility. Thus by employing copolymers containing oligothiophenic chains with a size of about 8 nm, the power conversion efficiency (PCE) (4.46%) and short current density (JSC) (16.15 mA cm−2) values are the highest reported so far for P3HT:PCBM solar cells on plastic substrates.

Two different carbon nanoforms (CNFs), namely multi-walled carbon nanotubes (MWCNTs) and carbon nanohorns (CNHs), have been chosen as support for the direct polymerization of a bis-vinylimidazolium salt. Transmission electron microscopy analyses revealed a templating effect of the CNFs on the growth of the polymeric network, which perfectly covers their whole surfaces creating a cylindrical or spherical coating for MWCNTs and CNHs, respectively. Subsequently, the CNFs-polyimidazolium have been used as stabilizers for Pd nanoparticles (Pd NPs), and the obtained materials have been characterized by means of analytical and spectroscopic techniques and then employed as easily recoverable and recyclable catalysts for Suzuki and Heck reactions. Quantitative conversions have been obtained in almost all the explored reactions, even employing low loading of catalyst (down to 0.007 mol%). Suzuki reactions were carried out in pure water under aerobic conditions. Both materials showed excellent activity and recyclability for the investigated C-C coupling reactions, with the CNHs-based material resulting slightly more active than the MWCNTs-based one due to a higher superficial exposure of Pd NPs.

Polyhedral oligomeric silsesquioxanes (POSS) have been employed as molecular building blocks for the synthesis of imidazolium cross-linked networks, to be used as heterogeneous catalysts for the conversion of carbon dioxide into cyclic carbonates. Two hybrid materials with different nucleophilic species (bromide and iodide) have been prepared and characterized by means of elemental analysis, 13C and 29Si solid-state NMR spectroscopy, thermogravimetric analysis and IR spectroscopy. The solids were tested as the sole catalyst under metal- and solvent-free reaction conditions showing full selectivity toward the formation of cyclic carbonates. High turnover number (TON) and productivity values, up to 5502 and 1081 respectively for glycidol conversion at 100 °C and up to 4942 and 1122 for epichlorohydrin conversion at 150 °C after 3 h, were obtained. Such outstanding productivity values were ascribed to the optimal organic/inorganic (i. e., imidazolium moiety/POSS support) weight ratio. The recyclability of the materials was successfully verified for five consecutive runs allowing their consideration as promising candidates for continuous flow technologies.

The application of nanocarbons as useful scaffolds for the production of a wide range of catalytic systems is an ever-growing field as witnessed by the huge amount of research on this topic. Both covalent and non-covalent modifications of nanocarbons represent the main routes to gain access to hybrid nanostructured catalysts. In this chapter the attention will be focused on nanocarbons, namely, fullerene, nanotubes, and graphene, employed for catalytic purposes covering both organocatalytic and metal-based (metal nanoparticles, organometallic complexes) reactions, whereas simple physical mixtures of nanocarbons and metal nanoparticles as well as examples dealing with electrocatalysis or photocatalysis are out of the scope of the present chapter. Because of the large number of publications in this field, we dealt some recent examples that represent a short overview on this topic that are not meant to be exhaustive but merely representatives of the subject.

We report the synthesis and catalytic properties of single-walled carbon nanotube-polyamidoamine dendrimers hybrids (SWCNT-PAMAM), prepared via a convergent strategy. The direct reaction of cystamine-based PAMAM dendrimers (generations 2.5 and 3.0) with pristine SWCNTs in refluxing toluene, followed by immobilization and reduction of [PdCl4](2-), led to the formation of highly dispersed small palladium nanoparticles homogeneously confined throughout the nanotube length. One of these functional materials proved to be an efficient catalyst in Suzuki and Heck reactions, able to promote the above processes down to 0.002 mol % showing a turnover number (TON) of 48 000 and a turnover frequency (TOF) of 566 000 h(-1). In addition, the hybrid material could be recovered and recycled for up to 6 times. No leaching of the metal has been detected during the Suzuki coupling. Additional experiments carried out on the spent catalyst permitted to suggest that a "release and catch" mechanism is operative in both reactions, although during Heck reaction small catalytically active soluble Pd species are also present.

A thermo-responsive polymer such as poly(N-isopropylacrylamide) (PNIPAAM) was covalently grafted on the external surface of halloysite nanotubes (HNTs) by means of microwave irradiation. This nanomaterial was used as a support and stabilizer for palladium nanoparticles. The obtained HNT–PNIPAAM/PdNPs was characterized by means of TGA, SEM, EDS and TEM analyses. The palladium content of the catalyst was estimated to be 0.4 wt%. The stability of the catalytic material at different temperatures (below and above the PNIPAAM lower critical solution temperature) was tested in the Suzuki reaction under microwave irradiation. In addition, TEM analysis after five consecutive runs was performed. The catalyst showed a good catalytic activity toward the Suzuki cross-coupling reaction between phenylboronic acid and several aryl halides in aqueous media under microwave irradiation and low palladium loading (0.016 mol%, 8 mg of Pd). Turnover numbers (TONs) and frequencies (TOFs) up to 6250 and 37 500 h1, respectively, were reached. The catalyst was easily separated from the reaction mixture by centrifugation and reused for five consecutive cycles with a small drop in its catalytic activity.

Supported ionic liquids (SILs) represent a class of materials with peculiar properties and a huge potential regarding their possible applications in different fields of chemistry. Herein, we report our ongoing research about the use of SILs as support for organocatalysts, their role as catalysts themselves, and their application as support and stabilizers of palladium nanoparticles (PdNPs). The use of SILs based materials allowed achieving good results. Moreover, in some cases, after the functionalization of the catalytic species with an ion-tag moiety, a release and catch approach was employed in order to improve the catalytic activity and to facilitate the recovery of the hybrid system formed by the catalyst adsorbed onto SILs materials. All the reported examples demonstrate the versatility of such SILs materials, which can represent powerful tools able to exert a large number of functions.

A C60-ionic liquid hybrid has been covalently linked to three different solid supports, namely amorphous silica, SBA-15 and Fe2O3@SiO2, and the resulting materials have been employed as covalently supported ionic liquid phases (cSILP) in order to immobilize and stabilize palladium nanoparticles (PdNPs). These novel hybrid materials are based on a sort of "matryoshka" system (PdNPs@imidazolium-salt@C60@support) in which the imidazolium-based moieties have not been directly linked to the surface of the support, but they are present in an octopus-like spatial arrangement on the uniformly surface-distributed fullerenes. These materials have been fully characterized and successfully employed as catalysts in C-C bond forming reactions showing, in the case of Suzuki cross-coupling, an outstanding catalytic activity both under classical heating and by irradiating with microwaves. Turn-over frequencies (TOFs) of up to 3640000 h-1 have been achieved and the silica-based catalyst showed full recyclability even after 10 cycles.

Primary and secondary benzylic alcohols and secondary aliphatic alcohols were oxidized to the corresponding aldehydes and ketones by using [bis(acetoxy)iodo]benzene (BAIB) and a catalytic amount of bromide ions, from tetrabutylammonium bromide or KBr, in ethyl acetate. The catalytic role of the bromide ions was also highlighted in the oxidation of primary aliphatic alcohols and secondary allylic alcohols carried out in the presence of 1 mol% TEMPO.

A novel fullerene (5:1)hexakisadduct bearing two 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) radicals and ten 1-propyl-3-methylimida- zolium bromide moieties has been synthesized and characterized. Such an C60IL10TEMPO2 hybrid has been successfully employed as a catalyst in the se- lective oxidation of a wide series of alcohols and is highly active at just 0.1 mol% loading. Moreover, it can be easily recovered by adsorption onto a multi- layered covalently-linked SILP phase (mlc-SILP) through a "release and catch" approach and reused for up to 12 cycles without loss in efficiency. Inter- estingly, a catalytic synergistic effect of TEMPO and imidazolium bromide moieties combined in the same hybrid has been clearly shown.

A modular approach has been followed for the synthesis of a series of fullerene-ionic-liquid (IL) hybrids in which the number of IL moieties (two or twelve), anion, and cation have been varied. The combination of C60 and IL give rise to new unique properties in the conjugates such as solubility in water, which was higher than 800 mg mL(-1) in several cases. In addition, one of the C60 -IL hybrids has been employed for the immobilization of palladium nanoparticles through ion exchange followed by reduction with sodium borohydride. Surprisingly, during the reduction several carbon nanostructures were formed that comprised nano-onions and nanocages with few-layer graphene sidewalls, which have been characterized by means of thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy/energy-dispersive X-ray analysis (SEM-EDAX), and high-resolution transmission electron microscopy (HRTEM). Finally, the material thus obtained was successfully applied as catalyst in Suzuki and Mizoroki-Heck reactions in a concentration of just 0.2 mol %. In the former process it was recyclable for five runs with no loss in activity.

Two different processes, namely the Bamford–Stevens and [4 + 2] Diels Alder reactions, have been optimized under microwave irradiation for the functionalization of fullerenes. In this manner, all the main C60- and C70-based acceptor derivatives for organic solar cells such as PCBM, DPM, BHN and ICBA, have been prepared in higher yields and shorter reaction times with respect to the reported data. These findings represent a step forward toward the wide production of cheaper organic solar cells as a consequence of the cost abatement of the acceptors given by higher yields, lower waste production, and reduced reaction time which means a strong energy saving.

Three different resin-supported catalysts have been prepared by using the well established post-modification approach by means of thiol-ene coupling reaction. Two catalysts were tested for the first time in the asymmetric α-selenenylation of propanal, while the third catalyst was used in the Michael addition reaction. While the preliminary results are not encouraging in the case of supported Jørgensen’ catalyst, interesting data have been collected with both for the supported MacMillan and prolyl-prolinol catalysts. In fact, these catalysts displayed good activity and selectivity. A reversed enantioselectivity in the α-selenenylation was observed by changing the polarity of the solvent. Finally, these materials were easily recovered, and used four and five times, respectively.

Piezoresistive sensors are considered among the fundamental components of the future wearable electronic devices, given their potential applications in artificial skin, motion capture and personalized medicine.[1-5] Here, we present a cost-effective, viable fabrication approach to realize piezoresistive sensors using a novel polymeric biotiophene fulleropyrrolidine system (bis-C60Bi) synthesized on flexible ITO/PET supports by electrochemical chronoamperometry. By applying an anodic potential (1.5 V) to a solution containing the monomer, it is possible to obtain a homogeneous semi-transparent thin film on the ITO/PET surface (see Figure). AFM, XPS, UV-vis have been employed to characterize the morphology and chemical composition of the new synthesized polymeric thin films, confirming the chemical structure and showing a nanoscale surface roughness of about 25 nm. The resulting polymer-based device shows good resistance variation on bending in the semi-static regime, outperforming current ITO/PET resistive sensors [6] and well matching commercial devices based on opaque amorphous carbon materials.[7] The durability of the sensor has been validated over almost one hundred cycles. This new class of polymeric piezoresistive sensors may open new applications in the field of kinematic acquisition or of sensor monitoring, with several potential applications as well as in medicine, robotics and physiotherapy. Bibliography 1 M. Ricci, G. Di Lazzaro, A. Pisani, N. B. Mercuri, F. Giannini, G. Saggio, IEEE Journal of Biomedical and Health Informatics, 2019, doi: 10.1109/JBHI.2019.2903627 2 G. Arrabito, V. Errico, Z. Zhang, W. Han, C. Falconi, Nano Energy, 2018, 46, 54. doi: 10.1016/j.nanoen.2018.01.029 3 G. Saggio, G. Orengo, A. Pallotti, V. Errico, M. Ricci, IEEE International Symposium on Medical Measurements and Applications (MeMeA), 2018, doi: 10.1109/MeMeA.2018.8438767 4 N. Jasoon, M.D. Ho, W. Cheng, J. Mater. Chem. C, 2017, 5, 5845. 5 G. Saggio ; G. Orengo ; A. Pallotti ; V. Errico ; M. Ricci, International Symposium on Networks, Computers and Communications (ISNCC) 2018 doi: 10.1109/ISNCC.2018.8531054 6 T. Lee, Y. W. Choi, G. Lee, P. V. Pikhita, D. Kang, S.M. Kim and M. Choi, J. Mater. Chem. C, 2016, 4, 9947. 7 G. Saggio, G. Orengo, Sensors and Actuators A, 2018, 273, 221.