The chapter reports the thermodynamic theoretical analysis of ethanol steam reforming (ESR) process for hydrogen production. The ideal ESR reaction (C2H5OH + 3H2O → 2CO2 + 6H2) and a set of subreactions, occurring during the ESR process, have been considered, calculating the main thermodynamic parameters (ΔH, ΔS, ΔG, and Keq), as a function of temperature (T, K) and pressure (P, atm). Potential autothermal ESR reactions have been also considered for comparative purposes. The study mainly focused on the identification of the thermodynamically competitive reactions (desired and undesired), and the estimation of the best conditions for obtaining hydrogen as pure as possible, and reducing the possibility to bring about by-products (such as CO, CO2, CH4, …) that are undesired form a technological point of view.

A synthetic procedure has been developed to conjugate ferulic acid (FA) to an important natural polysaccharide derivative such as hyaluronic acid (HA). The activation of FA with 1,1'-carbonyldiimidazole (CDI) has been investigated. Two reactive intermediates, namely monoimidazolide 2 [i.e. (E)-3-(4-hydroxy-3-methoxyphenyl)-1-(1H-imidazol-1-yl)prop-2-en-1-one] and bisimidazolide 3 [i.e. (E)-4-(3-(1H-imidazol-1-yl)-3-oxoprop-1-enyl)-2-methoxyphenyl 1H-imidazole-1-carboxylate] were characterized from the point of view of their structure and reactivity. The ready isolation of bisimidazolide 3 and its reactivity support its potential usefulness in the feruloylation of molecular or macromolecular materials bearing hydroxyl moieties. Bisimidazolide derivative 3 has been found to be an effective reagent in the feruloylation of HA to give HAFA graft copolymers showing different grafting degrees (GD), which could be modulated by varying the reaction conditions. A series of HAFA derivatives showing different GD values has been prepared and submitted to an extensive macromolecular and rheological characterization in order to ascertain that the grafting of HA with FA does not degrade the polysaccharide backbone and to evaluate the role of GD in affecting solubility and rheological properties. The results suggested that relatively low GD values were sufficient to confer physical cross-linking capabilities resulting in the features of a strong gel of HAFA dispersions.

A new biorelevant polymer brush showing a polybenzofulvene backbone was synthesized by a “grafting through” approach based on click chemistry and spontaneous polymerization reactions. The easy polymerization of the relatively complex monomer (6-MOEG-9-TM-BF3k) suggests the existence of a particularly efficient recognition process capable of pre-organizing the monomer molecules for the spontaneous polymerization. 13C-NMR spectroscopy as well as UV-vis and fluorescence spectroscopy suggested for poly-6-MOEG-9-TM-BF3k the features of a vinyl (1,2) π-stacked polymer. The new polybenzofulvene derivative was found to interact with water at room temperature to give clear water solutions, but TEM analysis demonstrated the presence of macromolecular aggregates showing dimensions larger than those suggested by SEC-MALS analysis for the isolated macromolecules. DLS studies confirmed the presence of objects showing average dimensions in the range of 200–300 nm and suggested thermoresponsive colloidal properties for poly-6-MOEG-9-TM-BF3kmacromolecules. Finally, owing to its favourable absorption/emission properties and water solubility, the interaction of poly-6-MOEG-9-TM-BF3k with live cells was studied by fluorescence microscopy experiments, which revealed that the polymer brush was unable to enter live cells and alter cell morphology.

In this article, the results of a study in which a convincing link emerged between geochemistry and archaeology are discussed. Research into the origins of strong arsenic anomalies in southwest Tuscany helped in realising the correlation between ancient mining activities and higher levels of the element. Besides an indication about the source of arsenic pollution in this area, these results indicate that arsenic can be used to trace major archaeoindustrial settlements. This research can provide precious information about the medieval period, when land use and ore extraction were regulated, for the first time, by a mining code. Interesting data can also be obtained about the Etruscan population and their ability to extract and work various metals, which confirmed their predominance in central Italy in the pre-Roman period. This kind of study could also be extended to other substances.

There is a profound debate over how to assign greenhouse gas (GHG) responsibilities; therefore, we have decided to follow IPCC guidelines, as they offer the only standardized method. We have identified each type of greenhouse emission and its level of absorption. We have studied the province and its districts and municipalities. We have determined that the energy sector is that with the highest level of emissions, even if the per capita emissions of the Province of Siena are very low. This is caused by a very low level of industrialization and the presence of a local geothermal production of energy. In order to highlight this aspect, we have considered scenarios both with and without geothermal production. Our research was then focused on single districts (groups of homogenous municipalities) and municipalities, where we found great differences among the greenhouse emissions of the areas. We have constructed a map of the greenhouse emissions of the whole province. It has been interesting to note that there are 14 municipalities with net negative emissions, seven with low positive emissions, 12 with medium positive emissions and three with elevated positive emissions. These latter correspond to the main city and to two of the most industrialized municipalities.

The territory of Colline Metallifere, in SW Tuscany, is characterized by the presence of strong arsenic anomalies. Some hypotheses, formulated in the last 20 years, based on geological and mineralogical factors have failed to explain the peculiar distribution of this toxic element in soil, fluvial sediments and ground water. Our research group has been studying for four years the problem of arsenic pollution in this district to investigate the origin and the mechanism of As diffusion in the environment. In particular we started a comparative study based on the extensive sampling of the stream sediments of the main waterways of Colline Metallifere (Pecora, Bruna and Cornia and their tributaries). In this work we focused our attention on the stream sediments and the soil of the Cornia basin. The comparative analysis of Cornia and the other rivers of the area, together with the investigation of historical series of data, provided important information about the origin of contamination of the territory and the impact of ancient mining settlements on this phenomenon.

The macromolecular and aggregate structures of poly[ethyl 1-methylene-3(4-methylphenyl)-l-H-indene-2-carboxylateI (poly-BF1; a new polymer based on a functionalized benzofulvene moiety showing interesting properties, i.e., thermoreversible polymerization/depolymerization behavior, high solubility in the most common organic solvents, and susceptibility to molecular manipulation) have been investigated with NMR spectroscopy, absorption and emission spectrophotometry, and transmission electron microscopy (TEM). Moreover, the polymerization mechanism has been studied to obtain further information on the polymer structure. The collected evidence is consistent in indicating for poly-BF1 a vinyl (1,2) polymer structure stabilized by means of aromatic stacking interactions. Furthermore, TEM studies performed on metal replicas have shown that the polymer is liable to give nanostructured aggregates. (c) 2005 Wiley Periodicals, Inc.

In this article we report the physicochemical characterization of cationic liposomes loaded with orthocarborane and two of its sugar-containing derivatives. Carboranes are efficient boron delivery agents in boron neutron capture therapy, an anti-cancer treatment based on neutron absorption by 10B nuclei. Cationic liposomes were prepared using the positively charged DOTAP and the zwitterionic DOPE, as a helper lipid. These liposomes are currently used in gene therapy for their ability in targeting the cell nucleus; therefore they can be considered appropriate vectors for boron neutron capture therapy, in the quest of reducing the high boron amount that is necessary for successful cancer treatment. Boron uptake was determined by an original in situ method, based on neutron absorption. The structural properties of the loaded liposomes were studied in detail by the combined use of small angle x-ray scattering and small angle neutron scattering. These techniques established the global shape and size of liposomes and their bilayer composition. The results were discussed in term of molecular properties of the hosted drugs. Differences found in the insertion modality were correlated with the preparation procedure or with the specific shape and lipophilic-hydrophilic balance of each carborane.

The Colline Metallifere in SW Tuscany are characterized by strong anomalies in arsenic concentrations and distribution. The area is sparsely populated and largely wild, though it has been subject to human impact due to mining and metal processing since Etruscan and Roman times. In the Middle Ages it was exploited intensively for silver and copper. Until 1995, pyrite (FeS2) was mined and roasted to produce sulphuric acid and iron. Hypotheses based on geological and mineralogical factors formulated in the last 20 years have failed to explain the peculiar distribution of arsenic in the Colline Metallifere. Here we report preliminary results of widespread sampling and analysis of the fluvial sediments of rivers originating in this mining area. The data was analysed in relation to the archaeological features of the area, since the presence of ancient mining and ore processing sites can shed light on the peculiar distribution of arsenic. Comparison of data from two rivers and their respective contaminated and uncontaminated coastal lagoons also clarified the general mechanisms of arsenic mobility, pinpointing the source of arsenic contamination. The study methods also promise to be useful for discovering unknown archaeological sites.

Italian law concerning the remediation of polluted areas forces the responsible party of the contamination to provide the complete characterization of the site, the project and the operative tasks for cleaning up soils and waters. In this context, determining the origin of pollution is mandatory for a correct approach to the whole remediation process.Our research group has been studying for two years the problem of Arsenic pollution in the area of an industrial plant for the production of sulphuric acid (SA) from pyrite roasting. The plant is located in a former wetland, in Scarlino, southwest of Tuscany.Horizontal distribution shows an almost regular decrease in the As concentration going, far from the plant, but with the presence of "hot spots" ([As]> 600 ppm) at large distance. Other irregularities in the vertical distribution of As concentration in the clay-rich soil, were found.Several evidences identified the SA plant wastes as largely responsible for the high Arsenic levels of the soil, but other theories were suggested. One of the prominent explanations concerned the natural Arsenic anomaly of the area; this was proposed to explain the wide distribution of the element and its irregular trend. This hypothesis was supported by the fact that the site under study is relatively close (about 15 km south-west) to the "Colline Metallifere" mine field, from which pyrite and blended sulfides were extracted. In fact, As enriched sediments could be transported from the river and stream beds which originate in that area.In order to verify the basis of these theories and the mechanism of As diffusion in the environment, we started an extensive sampling of the stream sediments of several rivers which originate in the mining field area.Comparing all the data for Arsenic and other elements we were able to demonstrate that: i) the natural Arsenic levels were significantly lower than the values recorded in the site under study; ii) other wetlands with similar geo-mineralogical origin as the former Scarlino wetland did not present Arsenic and other metal anomalies; iii) all the high Arsenic values found in the stream sediments of the stream beds studied and in the soil were correlated with the presence of ancient mining sites or iron smelter.The results obtained are in favour of an anthropogenic source of the high Arsenic level in the site under study.

The structure of folic acid in solution was investigated by nuclear magnetic resonance (NMR) and theoretical calculations. Dynamical information and geometrical constraints were obtained by carbon-13 relaxation study, homo-nuclear NOESY spectra and hetero-nuclear 1H-13C NOE experiments. This set of experimental data was used for the molecular mechanics and molecular dynamic calculations. The accuracy of the final structure was established by the R(NMR) factor, which was calculated comparing the experimental NOESY cross-peaks intensities and the corresponding values simulated by using the complete relaxation matrix analysis (CORMA) approach.

The formation of intramolecular (CHX)-X-...(N,O) bonds and their persistence in solution were studied by Xray crystallography and NMR techniques in two different rotamers of a molecule containing the ortho-carborane cage, an amide group and a quinoline ring. Experimental data were confirmed by theoretical ab initio calculations. From the resolved structure of the two forms of this potentially active drug for boron neutron capture therapy, accurate bonding and geometric parameters were extracted for this non-classic hydrogen interaction, and their strength was calculated. These findings provided new insight in the theory of (CHX)-X-... bonds, which appear stronger and less rare than it was previously thought.

We report the analysis of the structure and dynamics of the calix[4]arene bis-crown derivative (Dc3) and the host-guest system formed by Dc3 and acetonitrile in a chloroform solution. NMR spectral measurements, molecular mechanics, and molecular dynamics calculations have been used. Results showed that the host-guest complex in solution has chemical shift values that are considerably different from those of the pure compounds and from the Dc3-acetonitrile mixture. Molecular mechanics simulations showed that Dc3 has a cavity with an almost circular cone shape and that the CN group of acetonitrile in the host-guest complex pointed toward the Outside of the cavity. This orientation appeared energetically favored. The value of the generalized order parameter (S-2) from C-13-NMR relaxation rates also showed that the methyl group of acetonitrile behaved as a free rotor in the Dc3 cavity with reorientational motion of almost two orders of magnitude faster than the aromatic carbons.

The solution structure of rifaximin and its derivative rifaximin OR (open ring) was determined by combining NMR experimental results, theoretical simulation of two-dimensional NMR spectra by complete relaxation matrix analysis (corma), and molecular dynamics calculations. In this study the structural rearrangements due to the opening of the aliphatic chain of rifaximin after the reduction process to form rifaximin OR were investigated. Close spatial proximity of CH(3)(14) and H28b protons detected by 2D-ROESY spectrum of rifaximin OR, which was not present in rifaximin and the down-field shift of CH(3)(34) protons in rifaximin OR (1)H spectrum were crucial to understand the structural modifications, which occurred within the system. The aliphatic chain of rifaximin OR was found to be no longer symmetrical with respect to the aromatic moiety. Although no dramatic structural rearrangements were detected, the aliphatic chain moved toward CH(3)(14), causing a reduction of the aromatic shielding contribution in particular on CH(3)(34).

The SPIn-Eco project has been proposed and funded with the aim of studying the Province of Siena (Italy) and the 36 municipalities into which it is divided from the viewpoint of sustainable development. Several sustainability indicators are used to point out the weak and the strong points for the territory with respect to sustainability. In this paper we have focused our attention on the following methodologies: emergy evaluation, ecological footprint, greenhouse gases balance. The sustainability analysis made during the SPIn-Eco project has produced a data set that allows a practical comparison among these approaches by means of a correlation analysis. The correlations among several indicators based on the above data set are shown. The aim of this paper is to underline the similarities and differences among the three methodologies through correlation analysis. Important correlations were found between ecological footprint and CO2 emissions as well as with the non-renewable exogenous part of emergy flow. No correlation was found between total emergy flow and total ecological footprint.

The structure-activity relationship studies on 2-quinolinecarboxamide peripheral benzodiazepine receptor (PBR) ligands have been refined with the aim of using these ligands as carriers of radionuclides and boron atoms. Some new ligands show enhanced affinity and steroidogenic activity with respect to reference compound 1 and are interesting candidates for radiolabeling and PET studies. Moreover, carborane derivative 3q, representing the first example of PBR ligand bearing a carborane cage, can be useful to explore an alternative mechanism in BNCT.

A new polymer based on a functionalized benzofulvene moiety has been synthesized by spontaneous polymerization of the monomer in the solid state. This polymer shows a very high molar mass, high solubility in the most common organic solvents, and thermoreversible polymerization properties. An interesting application in synthesis is reported.

In this communication, the presence of a persistent intramolecular C-H....O bond in solution, has been evidenced by NMR spectroscopy and theoretical calculations. The molecules under study were o-carboranyl beta-glycoside derivatives, in which, the donor group was the activated CH of the carboranyl residue and the acceptor atom was the glycosidic oxygen. The strength of the interaction and the geometry of the atoms involved were determined by ab initio calculations.