Search results for " FT-IR"

Effect of Organic Amendments on the Evolution of Soil Organic Matter in Soils Stressed by Intensive Agricultural Practices

2013

Losses of soil organic carbon often occur because of intensive agricultural practices that lead to removal of organic carbon following harvest production and to insufficient inputs. Organic amendments can be a very appropriate matrix for enhancing organic carbon content in very stressed agricultural soils. In general, they, enhancing soil organic matter, play an important role in environmental matrices due, for example, to their capacity in retaining water, in interacting with organic and inorganic pollutants, and in enhancing nutrient availability to plants. For this reason, the understanding of the mechanisms with which organic amendments interact with other chemicals in the environment i…

Confinement of chiral molecules in reverse micelles: FT-IR, polarimetric and VCD investigation on the state of dimethyl tartrate in sodium bis(2-ethy…

2008

Abstract The state of d and l -dimethyl tartrate confined within dry sodium bis(2-ethylhexyl) sulfosuccinate (AOT) reverse micelles dispersed in CCl 4 has been investigated by FT-IR spectroscopy, polarimetry, and vibrational circular dichroism (VCD). Measurements have been performed at 25 °C as a function of the solubilizate-to-surfactant molar ratio ( R ) at a fixed AOT concentration (0.158 M). The analysis of experimental data is consistent with the hypothesis that both enantiomers of dimethyl tartrate are mainly entrapped in the reverse micelles and located in proximity to the surfactant head-group region. The formation of this interesting self-organized chiral nanostructure involves som…

Structural investigations on diorganotin and triorganotin(IV) phosphomycin derivatives.

2008

Abstract Four new diorganotin(IV), (R = Me, Bu), and triorganotin(IV), (R = Me, Ph), derivatives of the phosphomycin disodium salt antibiotic[(1R,2S)-1,2-epoxypropylphosphonate]Na2 have been synthesized and their solid state configuration studied by X-ray crystallography, FT-IR, Mossbauer, UV–Vis spectroscopies. The X-ray diffraction investigation, performed on the bis[trimethyltin(IV)]phosphomycin, showed that the coordination geometry at all the Sn atoms is trigonal bipyramidal. The structure of the complex forms an unusual polymeric zig-zag planar network. The FT-IR and the 119Sn Mossbauer studies supported the formation of trigonal bipyramidal (Tbp) molecular structures, both in the dio…

Volatiles in pantellerite magmas: A case study of the Green Tuff Plinian eruption (Island of Pantelleria, Italy)

2013

Abstract The Green Tuff (GT) Plinian eruption, the largest in magnitude at Pantelleria, erupted 3 to 7 km3 DRE of pantellerite magma and a small volume of trachyte. Fifty-nine anorthoclase-hosted melt inclusions from the two basal pumice members were analyzed by FT-IR spectroscopy in order to assess the pre-eruptive H2O content in the pantellerite melt. Microanalytical methods were used to determine major element, Cl, F and S contents. Melt inclusions and glassy groundmasses have a nearly homogeneous pantelleritic composition (peralkaline index = 1.9-2.2) and variable water contents ranging from 1.4 to as high as 4.2 wt %, i.e. much higher than the 1.4 wt % of earlier published studies. The…

Petrographic and spectroscopic (FT-IR) study of Western Mediterranean obsidians geological sources and of a lithic collection from Ustica Island (Sic…

2019

I n this study we applied petrochemical methods (SEM-EDS; FT-IR) in order to characterize a group of obsidian flakes collected at Ustica island (Sicily). Despite the absence of obsidian geological outcrops, a lot of obsidian fragments still emerging from the lands of Ustica testify that the island was a major import center of obsidian during the prehistory. On this island, there are some prehistoric settlements, dated from the Neolithic to the Middle Bronze Age (6000- 1200 BC), in which the use of obsidian continued until the beginning of metals age. Our study includes: i) Macroscopic and microscopic optical observations, which allowed selecting 18 obsidian flakes (starting from 50 obsidian…

Il cammino del sole, gli spazi del giorno. Piano urbanistico del comune di Grammichele (CT) su lastra di ardesia dipinta

2008

Caratterizzazione di sostanza organica disciolta mediante rilassometria NMR in modalità fast field cycling

2009

Synthesis, Characterization and in vitro antimicrobial activity of dialkyltin(IV)bis(fusidate) complexes.

2008

The complexation of one steroid antibiotic of the fusidane family, sodium fusidate [sodium 2-16-acetyloxy-3,11-dihydroxy-4,8,10,14-tetramethyl-2,3,4,5,6,7,9,11,12, 13,15,16-dodeca hydro-1H-cyclopenta[a]phenanthren-7-ylidene)-6-methyl-hept-5-enoate = (Nafus)], by dialkyltin(IV) has been studied by conventional technique as FT-IR, Mössbauer and NMR spectroscopies. Analytical data supported the general formula Alk2Sn(IV)fus2 (Alk = Me, Bu). Infrared spectral data of the complexes imply the presence of both uni- and bidentate, ester-type and bridging carboxylate group, respectively. On the basis of FT-IR and 119Sn Mössbauer spectroscopy, in both Me2Sn(IV)fus2 and Bu2Sn(IV)fus2, trigonal bipyram…

Organotin(IV)derivatives neurotoxicity and their modulation by Baclofen

2008

Several new diorganotin(IV) and triorganotin(IV) complexes with 4-amino-3- (4-chloro phenyl)]-butanoic acid ( = Baclofen) have been synthesized and their structure investigated both in the solid state and in solution phase through spectroscopic methods (FT-IR, Mössbauer, 1H and 13C NMR). According to experimental analytical data, the stoichiometry of the complexes has been proposed as R2SnBac2 and R3SnBac, respectively for diorganotin(IV) and triorganotin(IV) baclofen complexes. (Baclofen = HBac; R = Me, Bu, Ph).

A new biodegradable and biocompatible hydrogel with polyaminoacid structure

2007

The preparation and physicochemical and biological characterization of a novel polyaminoacid hydrogel have been reported. The ,-poly(N-2- hydroxyethyl)-dl-aspartamide (PHEA) has been used as a starting polymer for a derivatization reaction with methacrylic anhydride (MA) to give rise to the methacrylate derivative named PHM. Photocrosslinking of PHM has been performed in aqueous solution at 313 nm and in the absence of toxic initiators. PHM-based hydrogel has been characterized by scanning electron microscopy, X-ray diffractometry, swelling measurements in aqueous media; the degradation of PHM-based hydrogel has been evaluated as a function of time in the absence or in the presence of ester…