Matters are not so clear on the physical side

According to ontological reductionism, molecular chemistry refers, at last, to the quantum ontology; therefore, the ontological commitments of chemistry turn out to be finally grounded on quantum mechanics. The main problem of this position is that nobody really knows what quantum ontology is. The purpose of this work is to argue that the confidence in the existence of the physical entities described by quantum mechanics does not take into account the interpretative problems of the theory: in the discussions about the relationship between chemistry and physics, difficulties are seen only on the side of chemistry, whereas matters highly controversial on the side of physics are taken for granted. For instance, it is usually supposed that the infinite mass limit in the Born-Oppenheimer approximation leads by itself to the concept of molecular framework used in molecular chemistry. We will argue that this assumption is implicitly based on an interpretative postulate for quantum mechanics, which, in turn, runs into difficulties when applied to the explanation of the simplest model of the hydrogen atom.     

Carboxylation of a linear low density polyethylene via gamma irradiation in presence of carbon dioxide in subcritical and supercritical conditions

In this work the molecular modifications induced in a linear low density polyethylene gamma irradiated in presence of carbon dioxide both in subcritical and supercritical conditions are presented. The obtained results indicate that this process can be a new and interesting way in order to graft oxidized groups in the polyethylene chains. Moreover it is worth noting that, together with these functionalization reactions, also a significant crosslinking occurs, with improvement in some mechanical tensile behaviour.     

Transfer processes of alkoxyl groups in iron carbonyl complexes

The mass spectra of Fe₂(CO)₆C₄(COOCH₃)₄ and Fe₂(CO)₆C₄(COOC₂H₅)₄ are reported. Transfer processes of alkoxyl groups and hydrogen rearrangements are observed, and confirmed by deuterium labelling and the observation of metastable transitions. Fe₃(CO)₈C₄(COOCH₃)₄ and Fe₃(CO)₈C₄(COOC₂H₅)₄ give similar breakdown patterns. Likely fragmentation schemes are suggested.     

Magnetic heat capacity of an amorphous Gd-Al alloy

The magnetic specific heat of amorphous GdAl₂ shows a broad maximum near 17.5 K, the temperature of the spin-glass-like cusp in the magnetic susceptibility. At low temperatures it varies as $\text{T}{}^{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$, with a small negative intercept. This is interpreted in terms of ferromagnetic spin waves excited in regions some 35 Å in size.     

Contribution à l'étude thermodynamique du système ternaire aluminum—gallium—étain

The heats of mixing of ternary liquid aluminum—gallium—tin alloys have been measured in a high temperature microcalorimeter at 995 K. The partial free energy of aluminium of such alloys have been obtained from e.m.f. measurements.These results, combined with the thermodynamic properties of the binary systems, enable the calculation of such properties in the whole composition range from which the phase diagram is derived.     

Room-temperature carbonization of poly(diiododiacetylene) by reaction with Lewis bases

Poly(diiododiacetylene) (PIDA) is a conjugated polymer containing an all-carbon backbone and only iodine atom substituents. Adding a Lewis base to the blue PIDA suspension at room temperature leads first to rapid disappearance of the absorption peaks attributed to PIDA, followed more slowly by release of free iodine. The resulting solid material gives a Raman scattering spectrum consistent with graphitic carbon, and it has a much higher conductivity than PIDA itself. Further investigation has led to the discovery of a previously unreported transformation, the reaction of a Lewis base such as pyrrolidine with a trans-diiodoalkene to form the corresponding alkyne. The generality of this iodine elimination further suggests that reaction of PIDA with Lewis bases dehalogenates the polymer, presenting a new method to prepare carbon nanomaterials at room temperature under very mild conditions.     

Preparation of99mTc-thiourea complex as a precursor for Tc(III) labeled compounds

Ligand exchange is one of the possible synthetic routes to obtain^99mTc coordination compounds. However, the success of this route depends on the availability of good precursors. The objective of this work is the preparation of the complex [^99mTc(tu)₆]³⁺ (tu = thiourea), as a potential precursor for^99mTc(III) coordination compounds. The preparation was successfully performed in acidic conditions, the excess of tu serving as reducing agent. At pH values higher than 3, the compound becomes unstable and on addition of polydentate ligands new Tc(III) complexes are formed. With edta, the complex^99mTc(III)-edta was obtained in high yield.     

The formal redox potential of the Ti(IV, III) couple at 25 degrees C in 1 M HCl 2 M NaCl medium

The formal redox potential of the Ti(IV, III) couple has been determined at 25 degrees C in 1 M HCl, 2 M NaCl aqueous medium, by emf measurements of a junction-free cell with glass and mercury electrodes. Ti(III) and Ti(IV) concentrations were changed by controlled electrolysis. The mean value of the searched formal potential, in a large range of total titanium concentration, is 9 +/- 1 mV against the molar hydrogen electrode in the same ionic medium.