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Nel contributo, si ricorda la figura del Professor Angelo Mangini, attivo presso la Facoltà di Chimica Industriale dal 1938 al 1978. In particolare, vengono sottolineati i suoi rapporti con importanti scienziati internazionali nel campo della chimica organica.

5-Hydroxy-4-keto-2-pentenoic acid (HKPA) is characterized by the presence in its chemical structure of four different chemical groups (hydroxyl, keto, carboxylic and unsaturated groups) that render it a possible intermediate or monomer in the chemical industry. The production of this compound is studied by the sensitized photo-oxidation of 5-hydroxymethylfurfural (5-HMF) in aqueous solution at acidic pH. 5-HMF can be easily obtained through the degradation of saccharides such as fructose or inulin. The system reactivity is influenced by the concentration of methylene blue (BM) which is used as the photosensitizer and the oxygen dissolved in the solution. Only moderate consumptions of the sensitizer are recorded during the oxidation experiments thus suggesting the possibility to recover and reuse it in new runs. No differences in the reactivity of the system and/or selectivity for HKPA are observed as a result of changes in the starting concentration of the substrate and/or pH. A simplified reaction scheme of photo-oxidation of 5-HMF is proposed. Two kinetic models are developed according to this scheme to simulate the photo-oxidation processes of the substrate in the absence and in the presence of methylene blue. A validation of these models is carried out by means of the experimental data, collected at pH = 6.0, at different initial concentrations of 5-HMF and BM. © 2009 Elsevier B.V. All rights reserved.

Supramolecular chemistry gives powerful tools to scientists for fabrication of new functional materials. Constant studies over nature of multiple interactions in biological systems, their application in chemistry and material science, finally fabrication of new devices available for wide community, allow progress and help humanity in everyday life. The present thesis is focused on design of applied supramolecular architectures for fascinating applications in material science, synthesis of building blocks for these systems and final assembly of subunits into functional materials, when possible. Main part of thesis harvest exceptional complexation properties of tetraphosphonate cavitands towards charged organic ammonium salts. They have been employed for building hierarchical luminescent complexes on silicon (Chapter 3), synthesis of luminescent dyes aligning in liquid crystal displays (Chapter 4), sensing of charged amines in water environment (Chapter 7), and their model compound, metal bridged cavitands, have been synthesized as building blocks for metal organic frameworks (Chapter 2). Second part of thesis is focused on chemistry of phthalocyanines, synthetic macromolecules with particular optical and electronic properties, which upon proper functionalization and organization on the surfaces can find applications in organic photovoltaics as very strong light absorbents and electron donors/acceptors (Chapter 5). Sandwich complexes with terbium opened area of new applications in spintronics due to its single molecule magnet properties (Chapter 6), where rational organization on surfaces is crucial.

In this thesis the design, synthesis and characterization of cavitand based receptors for chemical sensing and environmental analyses is discussed. The thesis is organised in three main topics: (1) Design and synthesis of novel Qx-BOX receptors for Benzene detection in air (Chapter 1) The development of a cavitand-based selective pre-concentrator unit for benzene detection in air. The cavitands developed for this propose are quinoxaline-based cavitands blocked in rigid vase configuration, obtained blocking the four quinoxaline walls with aliphatic linkers. The performances of these quinoxaline cavitands in detecting benzene at sub ppb level has been confirmed by SPME analyses. This new class of cavitands resulted fluorescent and the studies confirmed the increase of the fluorescent intensity upon BTEX complexation. (2) Water soluble Phosphonate cavitands (Chapter 4) The synthesis of a water-soluble tetraphosphonate cavitands to be used in human fluids for the detection of monometylated species as potential cancer marker is reported. Different synthetic approaches have been tested to synthesise a water soluble tetraphosphonate cavitand The best strategy resulted to functionalize the cavitand at the upper rim with four ethylphosphonate bridging units and at the lower rim with four pendant amino groups. (3) Lanthanides inclusion in molecular containers (Chapter 5) The aim of this study was the self-assembly of supramolecular cages incorporating luminescent lanthanide complexes. The ability of different molecular cavities to coordinate luminescent Lanthanide complexes has been studied both in solution and in the solid state. Different approaches were undertaken to encapsulate Lanthanide complexes in different cages like: solvent free assembly, hydrophobic effect using water soluble molecular container and multiples interactions with metal ions.

The present thesis deals with the application of molecular recognition in materials science. In particular, we report the formation of supramolecular polymers and sensor harnessing the outstanding recognition properties of tetraphosphonate cavitands towards N-methylpyridinium and N-methylammonium salts. The first part reports the self-assembly of a stimuli responsive supramolecular homopolymer, obtained by synthesizing a sarcosine derived cavitand monomer. The self-assembly and stimuli responsive properties of the homopolymer have been demonstrated with several techniques (NMR spectroscopy, light scattering, TEM). This host-guest counterpart were embedded in real polymers (PS and PBMA) as comonomers, to test their ability to promote polymer blending, and to investigate the responsiveness of this complex in a truly polymeric material. The second topic concerns the selective sensing of illicit drugs like methamphetamines and cocaine without interference from other molecules bearing N-methylated groups like sarcosine. To this purpose a new fluorescent tetraphosphonate cavitand chemosensor bearing two distal pyrene unit has been designed, synthesized and tested. The fluorescence results indicated that the cavitand is an efficient chemosensor for the family of illicit drugs in aqueous solution. In the final topic we studied the self-assembly of differently charged supramolecular vesicles driven of a ternary host-guest complex based on cucurbit[8]uril. The vesicles size distribution and morphology have been characterized in details by DLS, TEM and ESEM. La presente tesi si occupa delle applicazioni del riconoscimento molecolare nella scienza dei materiali. In particolare si riportano la formazione di polimeri supramolecolari e sensori sfruttando le selettive proprietà di riconoscimento molecolare dei cavitandi tetrafosfonati verso sali di N-metil-piridinio e di N-metil-ammonio. Nella prima parte della tesi è stato studiato il self-assembly di un omopolimero supramolecolare reversibile con stimoli acido-base. Il polimero è stato ottenuto sintetizzando un monomero basato su un cavitando tetrafosfonato funzionalizzato con sarcosina. Le proprietà di self-assembly e di reversibilità sono state dimostrate con differenti tecniche di caratterizzazione (spettroscopia NMR, light scattering, TEM). Questa coppia host-guest è stata successivamente incorporata come comonomero in due polimeri (PS e PBMA), per testare la loro abilità di promuovere la formazione di blend polimerici, e per investigare la loro capacità di rispondere a stimoli esterni allo stato solido. La seconda parte della tesi si occupa del sensing selettivo di droghe come metamfetamina e cocaina. A questo scopo è stato sintetizzato e testato un nuovo sensore supramolecolare basato su un cavitando fluorescente funzionalizzato con due molecole di pirene in posizione distale. I dati di fluorescenza raccolti in questo lavoro indicano che il cavitando è un efficiente chemo-sensore per la classe di molecole delle droghe N-metilate. Nell’ultima parte della tesi e’ stato studiato il self-assembly di vescicole cariche supramolecolari. Questi aggregati sono stati costruiti su un complesso host-guest ternario a base di cucuribit[8]urili. Le dimensioni e morfologia delle vesicole sono state caratterizzate in dettaglio attraverso esperimenti DLS, TEM and ESEM.

The base of supramolecular chemistry rests on molecular recognition, that is the selective recognition of substrate molecules (guest) by synthetic receptors (host). The present thesis deals with the selective recognition properties of tetraphosphonate cavitands towards N-methylpyridinium and N-alkylammonium salts. In the first part of the thesis an extensive study of the thermodynamics of the complexation properties of tetraphosphonate cavitands towards N-methylpyridinium salts in solution via Isothermal Titration Calorimetry (ITC) is reported. The information obtained by the ITC in the recognition process of the receptor towards N-methylpyridinium salts were then exploited for the design of a new type of non-covalently linked-cavitand-stopped rotaxane. In the second part of the work, the complexation properties of cavitands were assessed towards N-alkylammonium salts at the solid-liquid interface via microcantilevers reaching an unprecedented real-time label-free selectivity. ITC was used as an independent tool for confirmation and rationalization of the results obtained with microcantilevers-based sensor. This approach has been then benchmarked by differentiating biological important molecules like sarcosine and glycine in water, reaching unique performances. The results obtained for the N-alkylammonium salts series opened the route to use microcantilevers for the online monitoring and the label-free sensing of biologically active ammonium-based molecules like drugs. The first experiments performed to test the recognition properties of tetraphosphonate cavitands towards drugs at the solid-liquid interface are described. La base della chimica supramolecolare risiede nel riconoscimento molecolare, cioè nel selettivo riconoscimento delle molecola di substrato (guest) da parte del recettore sintetico (host). La presente tesi si occupa delle selettive proprietà di riconoscimento dei cavitandi tetrafosfonati verso i sali di N-metilpiridinio e di N-alchilammonio. Nella prima parte della tesi è riportato uno studio estensivo relativo alla termodinamica delle proprietà complessanti dei cavitandi tetrafosfonati verso i sali di N-metilpiridinio tramite Titolazione Calorimetrica Isoterma (ITC). Le informazioni ottenute tramite ITC riguardanti il processo di riconoscimento del recettore con i sali di N-metilpiridinio sono state successivamente sfruttate per il design di una nuova tipologia di rotaxano, utilizzando i cavitandi come stopper non covalentemente legati all'asse. Nella seconda parte del lavoro sono state studiate le proprietà complessanti dei cavitandi nei confronti dei sali di N-alchilammonio all'interfaccia solido-liquido via microcantilever, raggiungendo una selettività label-free in tempo reale senza precedenti. La calorimetria, in questo caso, è stata usata come strumento indipendente per la conferma e la razionalizzazione dei risultati ottenuti tramite microcantilever. Questo approccio è stato poi testato differenziando molecole biologiche chiave come sarcosina e glicina in acqua, raggiungendo performance uniche. I risultati ottenuti per la serie di sali di N-alchilammonio ha aperto la strada per l'utilizzo dei microcantilever nel monitoraggio on-line e nel sensing label-free di molecole contenenti il gruppo amminico biologicamente attive come le droghe. Nell'ultima parte del lavoro vengono descritti gli esperimenti preliminari eseguiti per testare le proprietà di riconoscimento dei cavitandi tetrafosfonati verso le droghe all'interfaccia solido-liquido.

The food industry has a direct interest into bitter-tasting substances either for the identification of negative off-flavors or for the monitoring of a desired organoleptic quality. The present thesis takes its place in this context, and it deals with four main topics: 1) the simultaneous detection of xanthines and polyphenols, as bitter taste molecular markers, through a novel RP-HPLC-MS confirmatory method; 2) the xanthines and polyphenols detection in solid phase using a novel FT-NIR rapid method; 3) the polyphenols detection in liquid phase using a PEDOT based electronic tongue and a RAMAN based methods; 4) the development of a Design of Experiment oriented to demonstrate and quantify the correlation between different bitter taste molecular markers (polyphenols, xanthines, sugars and Maillard compounds) investigated with various analytical techniques (FT-NIR, RP-HPLC-MS, colorimetry and fluorescence) and the overall bitterness sensation measured by a panel group (PAA) in bakery products. L’industria alimentare ha un interesse nella determinazione delle sostanze responsabili del sapore amaro sia per l’identificazione di sapori sgradevoli che per il monitoraggio della qualità del sapore del prodotto finito. La presente tesi si colloca in questo contesto e si occupa di quattro tematiche principali: 1) la determinazione simultanea di xantine e polifenoli, come markers molecolari del sapore amaro, attraverso un nuovo metodo RP-HPLC-MS; 2) la loro determinazione in fase solida usando un nuovo metodo rapido basato su FT-NIR; 3) la determinazione dei markers molecolari del sapore amaro in fase liquida usando una lingua elettronica basata sul PEDOT e su un metodo RAMAN; 4) lo sviluppo di un disegno sperimentale volto a dimostrare la connessione tra i diversi markers molecolari (polifenoli, xantine, zuccheri e composti di Maillard) e il sapore amaro nei prodotti da forno.

Supramolecular chemistry is the ultimate strategy for the fabrication of innovative materials devote to accomplish advanced tasks. Mastering the weak interactions that held together the molecular components, a sophisticated structures appear. The present thesis deals with the formation of supramolecular networks via molecular recognition, covering three main topics: 1) the realization of hybrid organic-inorganic material, by polymer controlled association of gold nanoparticles; 2) the fabrication of sensor device, by combining molecular recognition functions with electrical properties of carbon nanotubes, and 3) the formation of polymer blending, as macroscopic expression of molecular recognition. All the topics have been exploited moving in the frame of cavitand chemistry. Several and complementary techniques, both in solution and in the solid state, allow for the comprehensive characterization of the formed networks, at different scale, ranging from molecular to macroscopic level. La chimica supramolecolare è la miglior strategia per la fabbricazione di materiali innovativi, importarti per svolgere funzioni avanzate. Grazie alla possibilità di scegliere e prevedere le interazioni che legano i componenti molecolari, è possibile costruire architetture molto sofisticate. Questa tesi si colloca all’interno di questo contesto affrontando tre linee di ricerca: 1) la realizzazione di materiali ibridi organici-inorganici, attraverso l’associazione controllata di nano particelle d’oro; 2) la fabbricazione di un sensore, inserendo funzioni di riconoscimento molecolare, in materiali grafici quali nano tubi di carbonio e 3) la formazione di miscele polimerica, per mezzo dell’espressione macroscopica del riconoscimento molecolare. Le nuove strutture ottenute sono state studiate attraverso diverse e complementari tecniche di caratterizzazione, muovendosi lungo la scala che collega il mondo microscopico a quello macroscopico.

Although coiled carbon nanofibers can be synthesized on large scale, the selective synthesis of coiled carbon nanotubes is still a challenge for the scientific community. In the present work we aimed to produce helically coiled CNTs (HCNTs) in at least 10% of the product, taking in consideration previous works. Alumina-, sepiolite and silica supported Co-; Fe-; Co-Fe and Co-Pr catalysts were prepared and tested in CNT synthesis reactions applying different conditions. Sepiolite and alumina supported catalysts showed low activity in the synthesis of HCNTs. The helices were maximum 1-2% of all the synthesized CNTs. A more detailed study was carried out with silica supported catalysts. The catalysts were prepared with the ion-adsorption-precipitation (IAP) method. A preliminary study was carried out to observe the behavior of different silica supported catalysts. Co-; Fe-; Co-Fe and Co-Pr catalysts were prepared with different metal loadings. Special attention was dedicated to the Co-Pr catalysts that showed higher activity in the HCNT production. The 2.5%Co-2.5%Pr; 4%Co-1%Pr and the 1%Co-4%Pr catalysts were chosen for a more detailed study. The effect of the temperature, the carbon source flow and the carrier gas flow variation was tested in the synthesis of helically coiled carbon nanotubes. The most favorable reaction conditions for the HCNT synthesis in our conditions are presented in table 1. Catalyst Reaction temperature (°C) C2H2 flow (ml/min) N2 flow %HCNTs 2.5%Co-2.5%Pr 700 30 300 15 4%Co-1%Pr 650 30 300 14-15 4%Co-1%Pr 700 30 600 14-15 1%Co-4%Pr 700 30 300 15-17 1%Co-4%Pr 700 30 600 14-15 Table 1.: Most favorable reaction conditions for HCNT formation over 5%Co-Pr catalysts with different metal ratios The synthesis products contain approximately 15% helically coiled MWCNTs. This gives the possibility to apply the synthesized HCNTs in nanocomposite materials, and exploit the peculiar properties of these structures. However, the purification process of the samples should be optimized. The characteristics, such as coil diameter and coil pitch, of the helices produced on 5%Co- Pr/SiO2 catalysts were analyzed. The morphology of these helices vary from wavy coils, Sshaped tubes, to tight helices and loose telephone-cord-like nanotubes. Their coil diameter varies from 25 nm to 270 nm but the most frequent values are present in the range of 25-50 nm. The coil pitch varies from 20 nm to 300 nm. The most frequent coil pitch values ae between 20-130 nm. Occasionally, helical tubes with coil pitch higher than 300 nm were found in the samples. In most of the samples S-shaped elongated coils are prevalent, however, tight coils are typical for the synthesis using 1%Co-4%Pr and the 4%Co-1%Pr catalysts applying different nitrogen flows. The aim of this work to obtain more than 10% of helically coiled carbon nanotubes in the synthesized product was achieved, however further study is needed to understand the formation of the helices and the role of the different reaction parameters Dottorato di Ricerca in Ingegneria Chimica e dei Materiali, Ciclo XXIII, a.a. 2007-2010 Università della Calabria

In this thesis we have investigated the crucial role of H-bonding interactions in supramolecular sensing and ion-channels formation. In the first case, we have demonstrated how the presence of a preorganized receptor, which bears specific functionalities, is essential for an effective molecular recognition process. In detail, we have conceived tetraphosphonate and mixed bridged thio-phosphonate cavitands, and probed their molecular recognition properties toward alcohols at the gas solid interface by using QCM sensor devices. On one hand, these receptors have shown a very high sensibility toward all alcohols and on the other, a good selectivity for short chain alcohols. In the second part of the thesis, we have directed the attention on different supramolecular structures able to self-assemble in ion-channel. We have conceived a ditopic guanosine-sterol derivative and we have tested its aggregation ability by using planar lipid bilayer experiments. Finally, we have demonstrated how the combination of the hydrophobic and hydrophilic aspects of this compound, affords the self-assembly of large and stable transmembrane ion-channels In questo lavoro di tesi, si è analizzato il ruolo fondamentale delle interazioni di legame di idrogeno nei sensori supramolecolari e nella formazione di ion channels. Nel primo caso, si è dimostrato che per un efficace riconoscimento molecolare è necessaria la presenza di un recettore dalla struttura preorganizzata e caratterizzata da specifiche funzionalità. In particolare, si sono realizzati cavitandi tetrafosfonati e tiofosfonati a ponti misti, e si sono testate le loro proprietà di riconoscimento molecolare all’interfaccia gas-solido verso gli alcoli, utilizzando sensori QCM. Da un lato questi recettori hanno mostrato un’ elevata sensibilità verso tutti gli alcoli e dall’altro una buona selettività per gli alcoli a catena corta. Nella seconda parte di questa tesi, si è rivolta l’attenzione verso differenti strutture supramolecolari capaci di auto-assemblarsi in ion channels. In questo caso si è sintetizzato un derivato steroideo di topico della guanosina e si sono testate le sue capacità di aggregazione in membrane lipidiche. Si è dimostrato come la somma degli aspetti idrofobici ed idrofilici di questo composto portano alla formazione di grandi e stabili canali ionici trans membrana.

The design, synthesis, and characterization of cavitand based materials for application in chemical sensing and environmental analyses are the main topic of this thesis. The thesis is organized in three main projects: (1) The development of a portable miniaturized system for environmental monitoring of benzene in outdoor air. Using quinoxaline cavitands as preconcentration unit, it is possible to detect benzene at ppb level with MOX sensors. The sensor has shown efficient performances not only in laboratory tests but also in real world measurements. (2) The development of a coating, with molecular recognition ability, for solid phase microextraction fibers (SPME) for aromatic VOCs from aqueous samples. With this coated fibers it is possible to sample and selectively desorb aromatic analytes at ppt level in presence of aliphatic interferents. (3) The design and characterization of highly specific fluorescent molecular receptors for short chain alcohols. The introduction of an appropriate fluorescent probe allows the specific detection of alcohols complexed into the cavity in the solid state. Il principale argomento di questa tesi è la progettazione, preparazione e caratterizzazione di materiali a base di cavitandi per applicazioni in campo sensoristico ed analitico. La tesi è stata sviluppata in tre temi principali: (1) Creazione di un sistema miniaturizzato portatile per il monitoraggio ambientale del benzene in aria. Utilizzando cavitandi chinossalinici come unità di preconcentrazione è stato possibile rilevare, con sensori MOX, benzene a livello di ppb direttamente dall’ambiente esterno. Il sensore realizzato si è dimostrato efficiente non solo nei test in laboratorio ma anche nelle prove in ambiente reale. (2) Realizzazione di un coating con proprietà di riconoscimento molecolare, mediante tecnica sol-gel, di fibre per microestrazione in fase solida (SPME) per analiti aromatici da campioni acquosi. Con questo materiale si possono campionare e desorbire selettivamente analiti aromatici a livello di ppt in presenza di interferenti alifatici. (3) Progettazione e caratterizzazione di recettori molecolari fluorescenti altamente specifici per la rilevazione di alcoli lineari a catena corta. L’introduzione di un gruppo fluorescente opportuno permette la determinazione specifica di alcoli in cavità allo stato solido.

Dottorato di Ricerca in: Ingegneria Chimica e dei Materiali, Ciclo XX,a.a. 2006-2007 Università della Calabria

Tra gli anniversari d'interesse chimico caduti nel 2007, rientrava a pieno titolo il centenario della pubblicazione del primo numero della rivista "La Chimica nell'Industria" da parte dell'editore Lavagnolo di Torino (1° gennaio 1907). L'evento, dimenticato anche dai chimici, è motivo d'orgoglio per l'editoria tecnica italiana. La rivista torinese, da non confondere con "La Chimica e l'Industria", organo ufficiale della Società Chimica Italiana, ha una storia interessante, brevemente rivissuta in questo articolo commemorativo.