Search results for "Mossbauer spectroscopy"
showing 8 items of 8 documents
Synthesis, characterization of diorganotin(IV) complexes of N-(2-hydroxyarylidene)aminoacetic acid and antitumour screening in vivo in ehrlich ascite…
2001
Some new diorganotin(IV) complexes have been prepared by reacting potassium N-(2-hydroxyarylidene)aminoacetate with R2SnCl2(R = Me,nBu,Ph). The complexes have been characterized by 1H,13C,119Sn NMR, IR and 119mSn Mössbauer spectroscopic techniques in combination with elemental analysis. In the solid state, the complexes possess penta- and hexa-coordinated tin centres. The hexa-coordinated tin complexes were found to dissociate in solution, giving rise to penta-coordinated species as revealed by 119Sn NMR spectroscopy. Antitumour screening in vivo of the complexes L4snPh2,L4SnPh2· Ph3SnCl and L4SntBU2·t Bu2SnCl2 (L4 = N-(2-hydroxyacetophenone)aminoacetate) is also reported. Copyright © 2001 …
Solid State Analysis of Metal-Containing Polymers Employing Mossbauer Spectroscopy, Solid State NMR and F EI TOF MALDI MS
2010
Polymers in general and metal-containing polymers in particular are often sparingly soluble or insoluble, in contrast to small molecules. Thus, special significance is attached to characterization techniques that can be applied to the materials as solids. Here, three techniques are discussed that give structural information gained from the solid material. Mossbauer spectroscopy is a powerful technique that may give information on the structure about the metal-containing moiety for about 44 different nuclei. Its use in describing the structure of the product obtained from organotin dichlorides and the unsymmetrical ciprofloxacin is presented along with the reaction implications of the result…
Mossbauer spectroscopic study of the thermal spin crossover in [Fe(II)(isoxazole)(6)](ClO(4))(2)
2008
The (57)Fe Mossbauer spectroscopy of mononuclear [Fe(II)(isoxazole)(6)](ClO(4))(2) has been studied to reveal the thermal spin crossover of Fe(II) between low-spin (S = 0) and high-spin (S = 2) states.Temperature-dependent spin transition curves have been constructed with the least-square fitted data obtained from the Mossbauer spectra measured at various temperatures between 84 and 270 K during a cooling and heating cycle. This compound exhibits an unusual temperature-dependent spin transition behaviour with T(C)(down arrow) = 223 and T(C)(up arrow) = 213 K occurring in the reverse order in comparison to those observed in SQUID observation and many other spin transition compounds. The comp…
Mössbauer thermal scan study of a spin crossover system
2010
Programmable Velocity equipment was used to perform a Mössbauer Thermal Scans to allow a quasi-continuous temperature study of the magnetic transition between the low-spin and a high-spin configurations in [Fe(Htrz)2(trz)](BF4) system. The material was studied both in bulk as in nanoparticles sample forms.
Preparation and structural characterization of organotin(IV) complexes with ligands containing a hetero {N} atom and a hydroxy group or hydroxy and c…
2005
AbstractTwenty-two n-butyltin(IV) and t-butyltin(IV) complexes of ligands containing an –OH (–C@O) group or –OH and –COOHgroups and an aromatic {N} donor atom were prepared by metathetical reactions. On the basis of the FT-IR and Mo¨ssbauer spec-troscopic data, molecular structures were assigned to these compounds. The binding sites of the ligands were identified by means ofFT-IR spectroscopic measurements, and it was found that in most cases the organotin(IV) moiety reacts with the phenolic form ofthese ligands. In the complexes with –OH and –COOH functions, the –COOH group is coordinated to the organotin(IV) centres in amonodentate manner. The 119 Sn Mo¨ssbauer and the FT-IR studies suppor…
Equilibrium, Structural and Biological Activity Studies on [Organotin(IV)]n+ Complexes
2008
Organotin(IV) compounds are characterized by the presence of at least one covalent C–Sn bond. The compounds contain tetravalent {Sn} centers and are classified as mono-, di-, tri-, and tetraorganotin(IV), depending on the number of alkyl (R) or aryl (Ar) moieties bound. The anions are usually Cl, F, O2, OH,–COO, or –S. It seems that the nature of the anionic group has only secondary importance in biological activity. The rapid rise in the industrial (catalyst in PVC and foam production), agricultural (fungicides and acaricides), and biological applications (wood, stone, and glass preservatives) of organotin(IV) compounds during the last few decades has led to their accumulation in the envir…
Diorganotin(IV) complexes ofD-galacturonic acid: solid-state and solution-phase structural study
2003
Three diorganotin(IV) complexes of D-galacturonic acid (H2GalA; R = Me, n-Bu, Ph), two of which are new derivatives (R = Me, Ph), have been synthesized and their solid-state and solution-phase investigated by IR, Mossbauer, 1H, 13C and 119Sn NMR spectroscopy. The FTIR data suggest that H2GalA, in the dialkyltin derivatives, behaves as a dianionic ligand, coordinating the tin(IV) atom through an ester-type carboxylate and deprotonated alcoholic hydroxo groups, whereas a bridging carboxylate occurs in the diphenyltin(IV) complex. Octahedral and trigonal bipyramidal local geometries on tin(IV) atoms are proposed for dialkyltin(IV)GalA and diphenyltin(IV)GalA complexes respectively on the basis…
Synthesis, chemical characterization and biological activity of new histone acetylation/deacetylation specific inhibitors: a novel and potential appr…
2013
Three new triorganotin(IV) complexes of valproic acid (vp1, Me3Sn-valproate; vp2, Bu3Sn-valproate; vp3, Ph3Sn-valproate) have been synthesized and investigated by spectroscopic and biological methods. An anionic, monodentate valproate ligand was observed, ester-like coordinating the tin atom on a tetra-coordinated, monomeric environment. The structures, though, can distort towards a penta-coordination, as a consequence of a long range O center dot center dot center dot Sn interaction. Crystallographic and NMR findings confirm this situation both in solid state and solution. Biological finding evidenced a clear cytotoxic action of the complexes in hepatocellular carcinoma cell cultures: one …