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Atomically dispersed iron sites within N-enriched C-networks are promising low-cost catalytic materials for electrochemical applications. At odds with their often-outstanding performance in challenging electrocatalytic processes (i.e. oxygen reduction reaction, ORR) their fabrication strategy frequently relies on trial-and-error approaches. Moreover, the complex chemical nature of these hybrids is often dictated by the use of highly aggressive etching/doping thermo-chemical treatments. Therefore, the development of simplified chemical protocols based on cheap and abundant raw materials ensuring highly reproducible synthetic paths with the prevalent generation of discrete single-atom sites in a definite coordination environment remains a challenging issue to be properly addressed. In this contribution, the synthesis of hierarchically porous and N-enriched C-networks prevalently containing Cl-FeN4 sites is proposed. The outlined procedure takes advantage of citrate ions as carriers for N-sites and a sacrificial C-source for the synthesis of N/C matrices. At the same time, the chelating character of citrate polyions fosters the complexation of transition metals for their ultimate atomic dispersion in C/N matrices. The procedure is finally adapted to the use of common inorganic hard templates and porogens for the control of the material morphology. Avoiding any thermo-chemical etching/doping phase, the as-prepared catalytic material has shown remarkably high ORR performance in an alkaline environment. With a half-wave potential (E1/2) of 0.88 V, a kinetic current density up to 109.6 A g-1 (normalized to the catalyst loading at 0.8 V vs. RHE) and outstanding stability, it largely outperforms commercial Pt/C catalysts and certainly ranks among the most performing ORR Fe-single-atom-catalysts (Fe-SACs) reported so far.

Solvent-assisted ligand incorporation (SALI) of the ditopic linker 5-carboxy-3-(4-carboxybenzyl)thiazolium bromide [(H2PhTz)Br] into the zirconium metal-organic framework NU-1000 [Zr6O4(OH)8(H2O)4(TBAPy)2, where NU = Northwestern University and H4TBAPy = 1,3,6,8-tetrakis(p-benzoic-acid)pyrene], led to the SALIed NU-1000-PhTz material of minimal formula [Zr6O4(OH)6(H2O)2(TBAPy)2(PhTz)]Br. NU-1000-PhTz has been thoroughly characterized in the solid state. As confirmed by powder X-ray diffraction, this material keeps the same three-dimensional architecture of NU-1000 and the dicarboxylic extra linker bridges adjacent [Zr6] nodes ca. 8 Å far apart along the crystallographic c-axis. The functionalized MOF has a BET specific surface area of 1560 m2/g, and it is featured by a slightly higher thermal stability than its parent material (Tdec = 820 vs. 800 K, respectively). NU-1000-PhTz has been exploited for the capture and separation of two pollutant gases: carbon dioxide (CO2) and nitrous oxide (N2O). The high thermodynamic affinity for both gases [isosteric heat of adsorption (Qst) = 25 and 27 kJ mol-1 for CO2 and N2O, respectively] reasonably stems from the strong interactions between these (polar) "stick-like"molecules and the ionic framework. Intriguingly, NU-1000-PhTz shows an unprecedented temperature-dependent adsorption capacity, loading more N2O in the 298 K

A tailor-made benzothiazolium bromide salt functionality (BzTz) is introducedviasolvent-assisted ligand incorporation (SALI) into the mesoporous Zr-based metal-organic frameworkNU-1000. The resultingNU-1000-BzTzcomposite has been thoroughly characterized in the solid state. The functional group loading has been determined through1H NMR analysis of the digested sample (5% HF-DMSO-d6): a maximum value of 1.7BzTzligand per [Zr6] node is achieved. The material preserves its pristine crystallinity after SALI, as witnessed by powder X-ray diffraction. The functionalized MOF has a slightly lower thermal stability than its parent material (Tdec= 780vs.800 K, respectively). The N2adsorption isotherm collected at 77 K disclosed that its BET specific surface area (1530 m2g−1) is lower than that of prisitineNU-1000(2140 m2g−1), because of the space taken and weight added by the dangling benzothiazolium groups inside the pores. A total CO2uptake of 2.0 mmol g−1(8.7 wt% CO2) has been calculated from the CO2adsoprtion isotherm collected atT= 298 K andpCO2= 1 bar. Despite the lower BET area,NU-1000-BzTzshows an increased thermodynamic affinity for CO2(isosteric heat of adsorptionQst= 25 kJ mol−1) if compared withNU-1000(Qst= 17 kJ mol−1), confirming that the presence of a polar functional group in the MOF pores improves the interaction with carbon dioxide. Finally,NU-1000-BzTzhas been exploited as a luminescent sensor for polluting anions (CN−, SCN−, OCN−, and SeCN−as sodium or potassium salts) in aqueous solutions, after bromide exchange. A marked reversible blue shift of its emission band from 490 to 450 nm is observed in all cases, with the associated emission color change from light green to blue under a UV lamp. The detection limit of CN−(1.08 × 10−6M) is much lower than that measured for the other “stick-like” anions considered in this study. The process occurs efficiently even in the presence of other competing ions (i.e.in ordinary tap water), opening promising application perspectives in cyanide luminescence sensing in drinking water.

Electrocatalytic hydrogen oxidation (HOR) and evolution (HER) reactions under alkaline conditions are kinetically sluggish processes even when Pt catalysts are employed. Despite having markedly slower kinetics, nanostructured nickel catalysts represent a cheaper and more sustainable alternative to benchmark Pt-based systems. Accordingly, researchers seek to develop Ni nanoparticle-based materials with enhanced electrocatalytic performance through the exploitation of favorable and catalytically advantageous metal-support interactions. In this contribution, we report the study of various N-doped/decorated carbon nanotubes (N-CNTs) as carriers for nickel nanoparticles (Ni-NPs), prepared by the decomposition of Ni(COD)2 as a metal precursor, a synthetic method that does not require organic stabilizers. All materials are thoroughly characterized (XPS, HR-TEM, STEM, and XRD) and tested as electrocatalysts for HOR and HER under an alkaline environment. We demonstrate how an increase in the nanotube surface basicity dictated by the presence of N-basic functional groups tunes the NiOx content of the metallic Ni NP surface, conferring higher electrocatalytic performance to the composites. Ni-NPs supported on N-CNTs prepared by exohedral functionalization of multiwalled carbon nanotubes with NH-aziridine functional groups (Ni/CNT-NAz) exhibit the highest HOR activity (16 A gNi-1 at 150 mV vs RHE). In terms of their performance for H2 evolution, Ni/CNT-NAz exhibits better onset potential and activity compared to its Ni-based counterpart prepared from pure-carbon networks (Ni/CNT). Worthy of note, Ni/CNT-NAz exhibited an HER Tafel slope (66 mV dec-1) approaching that of benchmark Pt electrocatalysts.

© 2017 The Royal Society of Chemistry. Pyridine decorated multi-walled carbon nanotubes (N Py -MW) have been successfully employed as a catalyst for the reduction of carbon dioxide to methyl borinate (R 2 BO-CH 3 ) in the presence of 9-borabicyclo[3.3.1]nonane. N Py -MW represents the first example of a heterogeneous, metal-free and durable catalyst for CO 2 hydroboration to methanol. A mechanistic cycle has been proposed on the basis of targeted blank experiments and a quantum chemical study, highlighting the non-innocent role played by the nanotube carrier in the final N Py -MW catalytic performance.

© 2017 Swiss Chemical Society. The last few years have witnessed a wonderful technological renaissance that boosted the development of carbon-based nanomaterials (CNMs) doped with light heteroelements and featuring hierarchical porous architectures as valuable metal-free catalysts for a number of key industrial transformations. To date, several approaches to their synthesis have been developed, although many of them lack any real control of the final doping and composition. In contrast, chemical functionalization offers a unique and powerful tool to tailor CNMs' chemical and electronic surface properties as a function of their downstream application in catalysis. Different catalytic processes (hydrolysis/esterification/transesterification reactions, C-C bond forming reactions, CO2 derivatization into products of added value and electrochemical oxygen reduction reactions (ORR)) can be conveniently promoted by these materials. In addition, selected examples from this series offer a valuable platform for the in-depth comprehension of the underlying reaction mechanisms. This perspective article offers an overview on the main examples of ad hoc chemically decorated CNMs successfully exploited as metal-free catalysts, highlighting at the same time the importance of the surface chemistry control for the design of more active, metal-free and single-phase heterogeneous catalysts.

© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimActivity and selectivity are key features at the basis of an efficient catalytic system for promoting the steam- and oxygen-free dehydrogenation (DDH) of ethylbenzene to styrene. The catalyst stability under severe reaction conditions, the reduction of leaching of its active sites, and their resistance to deactivation phenomena on stream are other fundamental aspects to keep in mind while synthesizing new catalytic materials for the process. Although the recent use of single-phase (doped or undoped) carbon nanomaterials has significantly contributed to improving this catalysis, the relationship between materials morphology and their chemical surface properties still remains to be addressed. Here, a class of highly microporous, N-doped covalent triazine frameworks (CTFs) with superior activity and stability in the DDH compared to the benchmark systems of the state-of-the-art is reported. Notably, a comparative analysis of their chemico-physical properties has unveiled the role of the “chemically accessible” surface basicity on the catalyst passivation on stream. Finally, the unique properties of the synthesized CTFs are demonstrated by their excellent H2 storage capability and CO2 absorption that rank among the highest reported so far for related systems.

© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Two coordination polymers of assorted dimensionality (1D, 2D) have been prepared, namely [Zn 3 (L 2Th ) 4 (OH) 2 ·2(HL 2Th )] ∞ (1) and [Zn(L 5Th )(OAc)] ∞ (2), starting from Zn II salts and the isomeric forms of the organic linker p-(thiazolyl)benzoic acid: p-(2-thiazolyl)benzoic acid (HL 2Th ) and p-(5-thiazolyl)benzoic acid (HL 5Th ). The isomers have been prepared ad hoc, following straightforward Pd-catalyzed C–C coupling reaction protocols. In 1, the deprotonated ligand is coordinated through its carboxylate group only, with dangling thiazole groups. The –COO – units are bridging adjacent metal centers, thus creating a 1D chain. The Zn 3 cluster is made of one six-coordinate (O h ) and two four-coordinate (T d ) Zn II ions; triple-bridging µ 3 -OH groups are balancing the overall positive charge. The structure of 2 is instead made of Zn 2 (carboxylate) 4 “paddle-wheel” dimers as the constituting inorganic node. The octahedral metal coordination sphere includes two µ-(κ-COO) benzoate spacers, two µ-(κ-COO) acetate ions, the thiazole N atoms coming from adjacent building blocks, and a weak Zn···Zn axial interaction. The resulting final assembly is two-dimensional (2D), where p-(5-thiazolyl)benzoate adopts a genuine µ-[κ(COO):κ(N)] bridging coordination mode. The luminescent properties of both polymers have been analyzed in the solid state; they feature ligand-centered emissions at λ = 434 nm (1) and λ = 427 nm (2). These electronic transitions fall in the visible region, giving the samples a characteristic blue color under an ordinary UV lamp (excitation at λ = 254 nm). The theoretical analysis of the electronic features of the ligands and related molecular orbitals reveals that the observed transitions are mainly of π→π* nature, involving π orbitals delocalized on both aromatic cycles. A significant (reversible) blueshift of the emission maximum of ca. 60 nm, from the visible to the UV region, has been observed for 1 when suspended in water.

© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimBis(amido)–TiIV and –ZrIV complexes stabilized by the bis(amidinate) ligands {C6H4-1,2-[NC(tBu)N(2,6-R2C6H3)]2}M(NMe2)2 [M = ZrIV, R = Me (3), R = iPr (4); M = TiIV, R = Me (5), R = iPr (6)] and {C6H4-1,2-[NC(tBu)N(2,6-Me2C6H3)]2}Zr(NMe2)3H (3·HNMe2) were prepared in fairly good yields by treating a (bis)amidine ligand C6H4-1,2-[NC(tBu)N(2,6-R2C6H3)H]2 [R = Me (1), iPr (2)] with an equimolar amount of the metal precursor M(NMe2)4 (M = ZrIV, TiIV). The salt metathesis reactions between equimolar amounts of the sodium amidinates C6H4-1,2-[NC(tBu)N(2,6-R2C6H3)]2Na2 and ZrCl4(thf)2 were also scrutinized to synthesize the corresponding ZrIV bis(amidinate) dichlorides {C6H4-1,2-[NC(tBu)N(2,6-R2C6H3)]2}ZrCl2 [R = Me (7), iPr (8)]. The coordination mode of the ligand to the MIV ions was strongly affected by the steric hindrance of the amidinate ligand (Me- vs. iPr-substituted aniline moieties) as well as by the nature of the ancillary groups bound to the metal center (NMe2 vs. Cl). The bis(amido) ligand with the 2,6-Me2C6H3 substituents at the amidinate nitrogen atoms coordinates to the zirconium ion in a tetradentate fashion both in solution and in the solid state (3 and 3·HNMe2). The compounds containing the bulkier 2,6-iPr2C6H3 units prefer a tridentate coordination mode (4). With the smaller TiIV ion, the bis(amidinate) ligands from this series are tridentate in the solid state (5 and 6), whereas they reversibly switch their denticity from tridentate to tetradentate (κ3 vs. κ4) in solution depending on the temperature. The ZrIV complex 4, featuring the bulkier bis(amidinate) ligand 2, shows a behavior similar to that of its TiIV analogue, that is, a tridentate ligand coordination in the solid state and a temperature-induced denticity change in solution. The standard thermodynamic parameters for the κ3/κ4 interconversions of the two model compounds 4 and 5 in [D8]toluene solution were determined from the respective linear van't Hoff plots. Finally, the ZrIV bis(chloride) complexes 7 and 8 invariably show a tetracoordinate mode for their bis(amidinate) ligands (1 and 2) in solution and in the solid state.

© 2017 Elsevier B.V.Cationic palladium complexes stabilized by a tridentate neutral (N,N,C) ligand containing a sterically hindered N-heterocyclic carbene (NHC) moiety have been prepared and characterized. The nature of the anionic counterion in the palladium complex has been varied to get crystals suitable for X-ray diffraction. The square planar structure of one of these complexes along with the axial contribution of the sterically hindered NHC fragment has been confirmed by X-ray analysis. In addition, all the isolated [(κ3-N,N,C)PdIICl]+X- [X- =Cl, PF6, BF4, B(C6H3Cl2)4] ion pairs have been scrutinized as catalysts in the cross-coupling Suzuki-Miyaura reaction between phenylboronic acid and variably substituted halo-aryl acceptors. Selected issues from this series have shown improved catalyst turn-over frequencies (TOFs) with respect to structurally related catalytic systems of the state-of-the-art.

© 2016Nanodiamonds (NDs) are recognized as a class of robust metal-free catalysts for the steam-free, direct dehydrogenation (DDH) of ethylbenzene (EB) to styrene (ST). In spite of that, some main drawbacks, such as their powdery form along with their tendency to form aggregates, limit their full exploitation at the industrial level. In this work, we describe the preparation of macroscopically shaped monoliths consisting of silicon carbide-based foams coated with a nitrogen-rich mesoporous carbon matrix (NMC) as a non-innocent glue for highly dispersed ND fillers. The NMC phase is prepared from cheap and non-toxic food-grade components and it prevents the undesired NDs agglomeration thus maximizing the reagents exposure throughout the catalytic DDH tests. Moreover, the NMC phase represents a key source of surface basicity capable of inhibiting the occurrence of EB cracking side reactions during the catalytic runs. As a result, the ND@NMC/SiC composite shows excellent dehydrogenation performance already at low ND loading if compared with the powdery NDs and/or the SiC-supported NDs of the state-of-the-art. Noteworthy, the ND@NMC/SiC composite presents its best catalytic performance under DDH conditions close to those used in industrial plants (reaction temperture up to 600 °C and EB concentrations up to 10 vol.%) with high ST rates (λcatal. of 9.9 mmolST gcat−1 h−1), ST selectivity over 96% and long term stability on stream.

© 2016 The Royal Society of Chemistry.In this paper, we describe the combination of two different synthetic approaches to carbon nanotube N-decoration/doping: the chemical functionalization with tailored N-pyridinic groups and the classical Chemical Vapor Deposition (CVD) technique. Accordingly, CVD-prepared N-doped CNMs (NMWs) and their N-decorated (chemically functionalized) counterparts (NMW@N1,2) have been prepared and used as metal-free electrocatalysts for the oxygen reduction reaction (ORR). It has been demonstrated that chemical functionalization occurs on the NMW surface sites responsible for their inherent electrochemical properties and "switches them off". As a result, the ORR promoted by NMW@N1,2 is fully controlled by the appended N-heterocycles. A comparative analysis of N-functionalized samples and N-doped (CVD prepared) materials is used to foster the hypothesis of a unique N-configuration (N-pyridinic) responsible for the overall electrochemical performance in NMWs. In addition to that, original electrochemical insights unveiled during the study are discussed and the truly metal-free action of NMW in ORR catalysis is demonstrated.

© 2016 American Chemical Society.A challenging task of modern and sustainable catalysis is to rethink key processes at the heart of renewable energy technology in light of metal-free catalytic architectures designed and fabricated from cheap and easily accessible building blocks. This contribution describes the synthesis of highly N doped, carbon nanotube (CNT)-netting composites from cheap raw materials. With physical mixtures of CNTs and food-grade components as the starting materials, their thermal treatment generates foamy, N-doped carbon-based architectures. The mesoporous nature of the N-doped carbon phase grown around intertwined carbon nanotube networks and the easy control of the final material 3D shape make the protocol highly versatile for its full exploitation in the production of materials for catalysis. In addition to offering unique advantages with respect to the classical N-doped CNT powders, the 3D metal-free composites are highly versatile systems for a number of liquid-phase and gas-phase catalytic processes, under a wide operative temperature range. In this paper we demonstrate their excellent and to some extent unique catalytic performance in two fundamental and catalyst-demanding processes: (i) the electrochemical oxygen reduction reaction (ORR) and (ii) the direct, steam-free dehydrogenation of ethylbenzene (EB) to styrene (ST).

Chemical hydrogen storage with small lightweight and hydrogen-rich molecules like ammonia-borane (NH3?BH3, AB, 19.3 wt.% H2) or amino boranes of general formula RNH2?BH3 (R = alifatic chain or cycle) is a topic of great interest, as witnessed by the exponential growth of the number of papers published in the recent literature. Transition metal complexes can catalyze H2 release from these species under mild conditions and offer great potential as H-storage materials. The reactions of assorted Co(I), Ir(I), Pd(II) and Ru(II) polyphosphine (Figure 1) and pincer type complexes with AB and amine boranes have been analyzed experimentally through variable-temperaure multinuclear (11B, 31P, 1H) NMR spectroscopy, kinetic rate measurements and kinetic isotope effect (KIE) determination with deuterated isotopologues. At the same time, a DFT modeling of the reaction mechanisms has been carried out, starting from the experimental data available. The results will be presented.

© The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.The novel class of bis-arylaminoacenaphthylenes (Ar-BIANH2) was employed for the preparation of zirconium and yttrium complexes to be used as catalysts for cyclohydroamination of a number of primary and secondary aminoalkenes. The complex [(2,6-iPr2C6H3-BIAN)Zr(NMe2)2(η1-NHMe2)] was isolated and completely characterized, including X-ray diffraction analysis. Despite its easy and almost quantitative isolation, it showed only moderate catalytic performance in the intramolecular hydroamination, irrespective of the cyclization precursor used. On the other hand, in situ generated YIII complexes obtained using the same class of ligands were found to be very active, leading to the hydroamination of substrates including those normally reluctant in undergoing cyclization such as those featuring an internal non-activated C...C double bond. Electron donating substituents and especially steric hindrance on the ligand improve the performance of the catalysts, allowing us to decrease the catalyst loading to 1 mol% in the latter case.

© 2016 American Chemical Society.The high pressure structural and reactive beahvior of graphene oxide (GO) in the presence of Ar, N2, and NH3 was studied in diamond anvil cells (DAC) by X-ray diffraction (XRD) and vibrational spectroscopy (FTIR and Raman), with the purpose of investigating the use of pressure for N-doping and functionalization of GO in high-density conditions. The pressure evolution of the interlayer d-spacing of GO during room temperature compression and decompression indicates the pressure-induced insertion of the selected systems between the GO layers and the stability of the GO layered structure at high pressure. Thermal and photoinduced reactivity was studied in GO with N2 and in GO with NH3 in different pressure conditions. The comparison of the infrared spectra of the recovered samples at ambient conditions with respect to the starting GO provides evidence for the occurrence of chemical reactivity of N2 and NH3 with GO, leading to N incorporation and GO functionalization, as also confirmed by the Raman spectra. The observed reactivity opens new perspectives for the high-pressure chemistry of GO and carbon-based nanostructured systems.

© 2016 The Royal Society of Chemistry.To demonstrate the potential of azido-substituted carbon nanotubes for application in nanomedicine, multiple-decorated oxidized multi-walled carbon nanotubes as drug delivery systems have been synthesized. These DDSs were able to carry doxorubicin inside breast MCF-7 cancer cell lines resulting in an enhanced cytotoxic effect with respect to the free drug. Decoration of the carbon nanotubes was accomplished through both covalent and non-covalent approaches: versatile click reactions and π-π interactions were exploited. To assess the internalization of the carbon nanotubes inside cells, decoration with a BODIPY fluorescent molecule was performed. Furthermore, the nanotubes were decorated with a biotin selector molecule to increase the uptake of the system by cancer cells. Comparative studies were performed on the complete drug delivery system to highlight its effect with respect to the free drug and the contribution of the selector in the internalization efficiency. Finally, preliminary in vivo tests were performed on MCF-7 inoculated mice. A net improvement in efficiency, concerning the minor growth of the tumors, has been found when using doxorubicin loaded on our drug delivery system with respect to free doxorubicin.

© 2015 Elsevier Ltd. All rights reserved. A pressure induced lattice expansion of Graphite Oxide (GO) in presence of NH3 was observed by X-ray diffraction during room temperature compression and decompression up to 7 GPa in a diamond anvil cell (DAC). A remarkable increase (∼11%) of the interlayer d-spacing of GO was observed between 0.2 and 1.1 GPa in the liquid phase of NH3, indicating the occurrence of molecular insertion between the GO layers. The expansion is reversible with the release of pressure, thus leading to a pressure induced breathing of the GO lattice. The presence of high density NH3 between the GO layers opens new perspectives for N-doping and chemical functionalization of GO and for designing new advanced carbon based nanostructured materials.

© The Royal Society of Chemistry 2015. The straightforward "dressing" of macroscopically shaped supports (i.e. β-SiC and α-Al2O3) with a mesoporous and highly nitrogen-doped carbon-phase starting from food-processing raw materials is described. The as-prepared composites serve as highly efficient and selective metal-free catalysts for promoting industrial key-processes at the heart of renewable energy technology and environmental protection.

© 2015 American Chemical Society. Palladium complexes of the novel unsymmetrical phosphine pyrazole-containing pincer ligands PCNH (PCNH = 1-[3-[(di-tert-butylphosphino)methyl]phenyl]-1H-pyrazole) and PCNMe (PCNMe = 1-[3-[(di-tert-butylphosphino)methyl]phenyl]-5-methyl-1H-pyrazole) have been prepared and characterized through single-crystal X-ray diffraction and multinuclear 1H, 13C{1H}, and 31P{1H} NMR spectroscopy. In preparations of the monomeric hydroxide species (PCNH)Pd(OH), an unexpected N detachment followed by C-H activation on the heterocycle 5-position took place resulting in conversion of the monoanionic {P,C-,N} framework into a dianionic {P,C-,C-} ligand set. The dinuclear hydroxide-bridged species (PCNH)Pd(μ-OH)Pd(PCC) was the final product obtained under ambient conditions. The "rollover" activation was followed via 31P{1H} NMR spectroscopy, and dinuclear cationic μ-OH and monomeric PdII hydroxide intermediates were identified. DFT computational analysis of the process (M06//6-31G∗, THF) showed that the energy barriers for the pyrazolyl rollover and for C-H activation through a σ-bond metathesis reaction are low enough to be overcome under ambient-temperature conditions, in line with the experimental findings. In contrast to the PCNH system, no "rollover" reactivity was observed in the PCNMe system, and the terminal hydroxide complex (PCNMe)Pd(OH) could be readily isolated and fully characterized. (Chemical Equation Presented).

© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. A series of azido-dyes were synthesized through Knoevenagel reactions of an azido-BODIPY with aromatic aldehydes. The nature of the substituents allowed the fine tuning of their spectroscopic properties. The dyes were used to decorate oxidized multiwalled carbon nanotubes (ox-MWCNTs), bearing terminal triple bond groups, by CuAAC reactions, affording fluorescent materials. This decoration allowed the efficient determination of the internalization of the ox-MWCNT derivatives by different model cancer cells, such as MCF7.

A facile and efficient method based on electrochemistry for the production of graphene-based materials for electronics is demonstrated. Uncharged acetonitrile molecules are intercalated in graphite by electrochemical treatment, owing to the synergic action of perchlorate ions dissolved in acetonitrile. Then, acetonitrile molecules are decomposed with microwave irradiation, which causes gas production and rapid graphite exfoliation, with an increase in the graphite volume of up to 600 %. Upon further processing and purification, highly dispersible nanosheets are obtained that can be processed into thin layers by roll-to-roll transfer or into thicker electrodes with excellent capacitance stability upon extensive charging/discharging cycles. The good exfoliation yield ( > 50 % of monolayers), minimal oxidation damage and good electrochemical stability of the nanosheets obtained were confirmed by scanning force and electron microscopy, as well as Raman spectroscopy and galvanostatic analyses.

© 2014 American Chemical Society. Neutral bis(alkyl)-organolanthanide complexes supported by tridentate {N-,N,N} monoanionic 5-methylthiazole- or benzothiazole-amidopyridinate ligands have been prepared and completely characterized: (LThiaMe2)Ln(CH2SiMe3)2 [Ln = Lu3+ (3), Er3+ (7), Yb3+ (8)] and (LBnThMe2)Lu(CH2SiMe3)2 (5). Similarly to related Y3+ systems, the nature of the thiazole unit controls the ultimate catalyst stability in solution. In the diamagnetic Lu3+ complex 5, a progressive and complete rearrangement of its metal coordination sphere takes place through a metal-to-ligand alkyl migration with subsequent benzothiazole ring-opening and generation of the Lu3+ mono(alkyl)-arylthiolate species stabilized by a tetradentate {N-,N,N,S-} dianionic ligand. On the other hand, the 5-methylthiazole-containing complexes 3, 7, and 8 showed no evidence of any ligand rearrangement. Complexes 3-8 have been tested as homogeneous catalysts in isoprene (IP) polymerization, after activation with selected organoborates. Binary systems 3/TB and 7/TB [TB = tritylium tetrakis(pentafluorophenyl)borate] show the highest activity and living character toward IP polymerization, affording polymers with relatively high trans-1,4-selectivity (up to 76.4%), moderate molecular weights (Mn up to 146′000 g/mol), and narrow polydispersities (Mw/Mn). Depending on the rare-earth ion of choice, a prevalent trans-1,4 (Lu3+, Er3+, Yb3+; up to 76.4%) or a dominant 3,4 (Y3+; 92.7%) polymer structure is observed. The influence of the ligand type, metal ion, and activator(s) on the ultimate catalyst activity and selectivity is discussed.

Stimuli-responsive biomaterials have attracted much attention for their prospective application in several fields including biomedicine, biotechnology and biosensing. On the basis of our previous work [1], we have succeeded in fabricating an implantable device for on demand chemical release in the form of a light-activated nanocomposite sponge [2]. The sponge consists of a porous chitosan scaffold containing a dispersion of gold nanorods (GNRs), which acts as an absorber of an incoming laser light, and of thermosensitive PCL-PEG-PCL micelles, which serve as a reservoir for the drug molecules to be released. The photothermal response of the GNRs contained inside the sponge triggers a contraction in proximal micelles, thus promoting the expulsion of the drug that in turn is released to the external environment. The peculiar features of the nanocomposite sponges impart a number of interesting characteristics to this drug release system, including the possibility of spatially confining the therapeutic treatment as well as of a precise control over the amount of released drug as a function of duration and power of the excitation light. [1] Matteini P et al. ?Chitosan films doped with gold nanorods as laser-activatable hybrid bioadhesives?. Adv Mater 22 4313 (2010) [2] Matteini P et al. ?Light-responsive nanocomposite sponges for on demand chemical release with high spatial and dosage control? J Mater Chem B DOI: 10.1039/C2TB00310D (2013)