Search results for "OCT"
showing 10 items of 3052 documents
Experimental and theoretical studies of the molecular and crystal structures of trialkoxy- and chlorodialkoxy-stibanes
2001
The molecular structures of triisopropoxystibane, Sb((OPr)-Pr-i)(3), and chlorodiisopropoxystibane, SbCl((OPr)-Pr-i)(2), were determined in the solid state by single crystal X-ray diffraction. Sb((OPr)-Pr-i)(3) forms discrete centrosymmetric dimers in the solid state via Sb . . .O-Sb interactions, leading to pseudo trigonal bipyramidal configurations of the four co-ordinate Sb atoms, while SbCl((OPr)-Pr-i)(2) forms chains via Sb . . .O-Sb and Sb . . . Cl-Sb bridges, resulting in five-co-ordinate Sb atoms with pseudo octahedral configurations. Comparison of the solid state structures and the density functional optimized molecular structures of Sb(OMe)(3), SbCl(OMe)(2) and their dimers reveal…
Octahedral distortion caused by hydrogen bonding in tris(diethylammonium) hexachloridoantimonate(III).
2010
The factors influencing the distortion of inorganic anions in the structures of chloridoantimonates(III) with organic cations, in spite of numerous structural studies on those compounds, have not been clearly described and separated. The title compound, [(C(2)H(5))(2)NH(2)](3)[SbCl(6)], consisting of isolated distorted [SbCl(6)](3-) octahedra that have C(3) symmetry and [(C(2)H(5))(2)NH(2)](+) cations, unequivocally shows the role played by hydrogen bonding in the geometry variations of inorganic anions. The organic cations, which are linked to the inorganic substructure through N-H...Cl hydrogen bonds, are clearly responsible for the distortion of the octahedral coordination of Sb(III) in …
Perfluoroalkyl substances in Breast milk, infant formula and baby food from Valencian Community (Spain)
2016
Environmental and human exposures to perfluoroalkyl substances (PFASs) are of emerging concern since they are persistent and bioaccumulative. The present study reports PFASs levels in human milk, infant formulas and baby food (dry cereals and pots) from the Valencian Community (Spain) in order to evaluate the infant exposure to these substances through the diet. The results show that perfluorobutanoic acid (PFBA) and perfluorooctanoic acid (PFOA) were in all the samples of the four selected matrices (except PFOA in one sample of dry cereal baby food). Perfluoroheptanoic acid (PFHpA) and perfluorodecanoic acid (PFDA) were also detected in 70% of the breast milk samples. In infant formulas, P…
Emerging dynamics in surfactant-based liquid mixtures: octanoic acid/bis(2-ethylhexyl) amine systems.
2012
This work focuses on the dynamic phenomena emerging in self-assembled transient intermolecular networks formed when two different surfactants are mixed. In particular, the relaxation processes in liquid mixtures composed by bis(2-ethylhexyl)amine (BEEA) and octanoic acid (OA) in the whole composition range has been investigated by dielectric spectroscopy and Brillouin spectroscopy. A thorough analysis of all the experimental data consistently suggests that, mainly driven by acid-base interactions arising when the two surfactants are mixed, supra-molecular aggregates formation causes the slowing down of molecular dynamics. This, in turn, reflects to longer-range relaxations. These changes ha…
New phosphathiamacrocycles containing polypypiridine units
2006
Abstract A new 2,2′-bipyridine-based phosphadithiamacrocycle: 3,3′-5-phenyl-2,8-dithia-5-phospha[9]-2,2′-bipyridinophane (L) has been synthesized by reacting 6,6′-bis(bromomethyl)-2,2′-bipyridine and dilithium 3-phenyl-3-phosphapenta-1,5-dithiolate. The phosphoryl derivative: 3,3′-5-oxo-5-phenyl-2,8-dithia-5-phospha[9]-2,2′-bipyridinophane (Lox) synthesized by direct oxidation of L at open atmosphere. Both compounds have been isolated as white solids containing different amounts of LiBr. The reaction of acetonitrile solutions of these solids with Fe(II) perchlorate gave the complexes [FeBr(L)](ClO4) · 2H2O and [FeBr(Lox)](ClO4) · 3H2O, which were crystallized as [FeBr(L)]Br · H2O and [ FeBr…
Apoteosis ideológica / 4
2004
Performance and modelling of retention in microemulsion liquid chromatography
2020
Abstract The capability of liquid chromatography with microemulsions (MEs) as mobile phases was studied for the analysis of four parabens (butylparaben, ethylparaben, methylparaben, and propylparaben) and seven β-adrenoceptor antagonists (acebutolol, atenolol, carteolol, metoprolol, oxprenolol, propranolol, and timolol). MEs were formed by mixing aqueous solutions of the anionic surfactant sodium dodecyl sulphate, the alcohol 1-butanol that played the role of co-surfactant, and octane as oil. In order to guarantee the formation of stable MEs, a preliminary study was carried out to determine the appropriate ranges of concentrations of the three components. For this purpose, mixtures of varia…
Gaining or losing PhDs: What are the effects on firms' linkages with universities?
2023
PhD graduates can help companies transfer knowledge from universities to firms. Scholars have analysed the determinants of PhD recruitment by firms and its effects on their innovation activities. However, little is known about what happens when a firm loses employees with PhDs. The aim of this paper is to compare the effects on the relationships of firms with universities when these firms lose PhDs versus when they hire PhDs to work in R&D. These effects may be symmetrical or non-symmetrical depending on the abilities of firms to retain the connections and knowledge acquired by hiring PhDs. We consider four types of relationships: collaboration with universities, universities as a source of…
In-Between discourse and genre: doctor-patient interaction in online communication. Formal and informal features in CMC
2012
Abstract This paper presents the results of a corpus-based study which investigates the genre of medical eexchanges between doctors and medical website users. Three conversational routines (greetings, politeness, formal and informal linguistic features) are analyzed. The framework of the study is what some researchers refer to as net linguistics (Posteguillo 2003), consisting of the linguistic study of Computer Mediated Communication (CMC). The findings indicate that health posts are a relatively informal type of d/p interaction which is largely influenced by e-mails and chat conventions.