New benzenogenic diene syntheses

3,8-Diphenylpyrene 5 and 3,10-diphenylpyrene 10 were synthesized from 1,5-dibenzylnaphthalene and 1,4-diphenylnaphthalene. Dibenzylnaphthalenes were dehydrogenated to the quinonoid compounds 2 and 7, followed by addition of maleic anhydride and dehydrogenation of the adducts to give the aromatic anhydrides 4 and 9. These were decarboxylated to the corresponding hydrocarbons. By an analogous sequence of reactions 3,9-diphenylanthranthrene and 4,9-diphenyl-1,12-benzoperylene were prepared starting from 3,8-dibenzylpyrene 12 and 3,10-dibenzylpyrene 17 respectively. 1,6-Diphenylcoronene was synthesized by a further benzenogenic diene synthesis starting from 4,9-diphenyl-1,12-benzoperylene.     

Dynamics of sorption of cyclopropane in various H- and Na-zeolites

The frequency response (FR) method has been applied to study the dynamics of cyclopropane adsorption in faujasite, mordenite, beta and ZSM-5 zeolites containing Brönsted or Lewis acid sites in the concentration range of 0.586-0.772 meq/g.     

Benzene Adsorption in Microporous Materials

The adsorption behaviour of benzene in silicalite-1, AlPO₄-5 and EU-1 has been investigated using gravimetric techniques and molecular simulation methods. For the one-dimensional, 12-membered ring (MR) channels of AlPO₄-5 and the unidirectional, 10-MR channels with 12-MR side pockets of EU-1, the isotherms of benzene show simple type I behaviour. For the three dimensional 10-MR channels of silicalite-1, an anomalous behaviour of the benzene molecules sorbed has been observed. Two steps at loadings of ca. 4 and 6 molecules per unit cell [m.(u.c.)⁻¹], respectively, and an hysteresis loop between loadings from 6 to 8 m.(u.c.)⁻¹ can be found in the isotherms of this system. These stepped isotherms can be classified as showing type VI isotherm behaviour but in this system the reasons behind the steps are of a new and novel nature. These abnormal adsorption properties have been ascribed to the subtle interplay of increased sorbate-sorbate interactions and decreases in the entropy of sorption due to the energetically heterogeneous surfaces which are present in silicalite-1. The composition and structure of the silicalite-1 samples also play an important role on the adsorption properties of this system.     

C3 vanadium(V) amine triphenolate complexes: vanadium haloperoxidase structural and functional models

The C 3 vanadium(V) amine triphenolate complex 1f has been characterized as a structural and functional model of vanadium haloperoxidases. The complex catalyzes efficiently sulfoxidations at room temperature using hydrogen peroxide as the terminal oxidant, yielding the corresponding sulfoxides in quantitative yields and high selectivities (catalyst loading down to 0.01%, TONs up to 9900, and TOFs up to 8000 h (-1)) as well as bromination of 1,3,5-trimethoxybenzene (catalyst loading down to 0.05%, TONs up to 1260, and TOFs up to 220 h (-1)).     

On the Asymptotic Behaviour of Some Nonlocal Problems

The goal of this paper is to study diffusion problems associated with nonlinear diffusions of nonlocal type. We give existence and uniqueness results for these kind of problems and investigate the asymptotic behaviour.     

Effects of Traditional and Modern Post-Harvest Withering Processes on the Composition of the Vitis v. Corvina Grape and the Sensory Profile of Amarone Wines

In the Valpolicella area (Verona, Italy) Vitis vinifera cv. Corvina is the main grape variety used to produce Amarone wine. Before starting the winemaking process, the Corvina grapes are stored in a withering (i.e., dehydrating) warehouse until about 30% of the berry weight is lost (WL). This practice is performed to concentrate the metabolites in the berry and enrich the Amarone wine in aroma and antioxidant compounds. In compliance with the guidelines and strict Amarone protocol set by the Consorzio of Amarone Valpolicella, withering must be carried out by setting the grapes in a suitable environment, either under controlled relative air humidity (RH) conditions and wind speed (WS)—no temperature modification is to be applied—or, following the traditional methods, in non-controlled environmental conditions. In general, the two processes have different dehydration kinetics due to the different conditions in terms of temperature, RH, and WS, which affect the accumulation of sugars and organic acids and the biosynthesis of secondary metabolites such as stilbenes and glycoside aroma precursors. For this study, the two grape-withering processes were carried out under controlled (C) and non-controlled (NC) conditions, and the final compositions of the Corvina dried grapes were compared also to evaluate the effects on the organoleptic characteristics of Amarone wine. The findings highlighted differences between the two processes mainly in terms of the secondary metabolites of the dried grapes, which affect the organoleptic characteristics of Amarone wine. Indeed, by the sensory evaluation, wines produced by adopting the NC process were found more harmonious, elegant, and balanced. Finally, we can state how using a traditional system, grapes were characterised by higher levels of VOCs (volatile compounds), whilst wines had a higher and appreciable complexity and finesse.     

Error removal by orthogonal subtraction (EROS): a customised pre‐treatment for spectroscopic data

In some applications of diffuse reflectance spectroscopy there may be substantial variability between the spectra from replicate measurements of what is nominally the same sample. A method called error reduction by orthogonal subtraction (EROS) is proposed to ameliorate the effects of this. The first step is to use principal component analysis (PCA) to identify the structure in the variability of replicate measurements. This is followed by subtraction of the modelled effects from the original spectral data matrix X by projection onto the subspace orthogonal to factors derived from the PCA. An application to the clinical diagnosis of colon lesions is presented, in which pre‐treatment of spectra using the proposed method is successful in reducing the complexity and increasing both the accuracy and interpretability of the subsequent classification model. Copyright © 2008 John Wiley & Sons, Ltd.