De bezonken actualiteit van een nieuwe wereldatlas

Contains fulltext : 179868.pdf (publisher's version ) (Open Access)14 december 199

Transition metal saccharide chemistry and biology: syntheses, characterization, solution stability and putative bio-relevant studies of iron-saccharide complexes

A number of Fe(III) complexes of saccharides and their derivatives, and those of ascorbic acid were synthesized, and characterized by a variety of analytical, spectral (FT-IR, UV-Vis, EPR, Mossbauer and EXAFS), magnetic and electrochemical techniques. Results obtained from various methods have shown good correlations. Data obtained from EPR, magnetic susceptibility and EXAFS techniques could be fitted well with the mono-, di- and trinuclear nature of the complexes. The solution stability of these complexes has been established using UV-Vis absorption and cyclic voltammetric techniques as a function of pH of the solution. Mixed valent, Fe(II,III) ascorbate complexes have also been synthesized and characterized. Reductive release of Fe(II) from the complexes using sodium dithionite has been addressed. In vitro absorption of Fe(III)-glucose complex has been studied using everted sacs of rat intestines and the results have been compared with that of simple ferric chloride. Fe(III)-saccharide complexes have shown regular protein synthesis even in hemin-deficient rabbit reticulocyte lysate indicating that these complexes play a role that is equivalent to that played by hemin in order to restore the normal synthesis of protein. These complexes have exhibited enhanced DNA cleavage properties in the presence of hydrogen peroxide with pUC-18 DNA plasmid

Synthesis, characterization and structure of Ti(IV) complexes of hydroxy-rich ligands

284-289<span style="font-size:14.0pt;line-height: 115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" color:black;mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:="" hi"="" lang="EN-IN">Coordination chemistry of two multi-hydroxy rich ligands has been explored with Ti(IV) by isolating the resultant products followed by their characterization. One of the products is also structurally characterized by single crystal XRD.</span

Formation of mono- and di-amide-calix[4]arene derivatives from the reaction of <i>p-tert</i>-butyl-calix[4]arene and <img src='/image/spc_char/alpha.gif' border=0>-chloro-<i>N</i>,<i>N</i>-diethylacetamide in the presence of sodium hydride

549-552The formation of mono- and di (1,2 and 1,3)-amide derivatives of p-tert-butylcalix[4]arene in the presence of sodium hydride has been demonstrated.  All the compounds have been purified and characterized by various spectral methods.  Both 1H and 13C NMR spectra exhibit clear-cut differences between the 1,2-di- and 1,3-di-amide derivatives.

Role of saccharides in reduction and complexation of transition metal ions and the effect of zinc saccharides on some haematological variables

This article does not have an abstract

Saccharide complexes of lanthanides

227-239The main focus of this review article is to bring out different aspects of interactions of saccharides with lanthanide ions. various characteristic properties of lanthanide-saccharide complexes have been compared appropriately with those of the transition metal ones

Oxo-metal complexes of alkoxo rich ligands and reactivity of vanadium complexes

Oxo-metal centers, such as, VO3+, cis-VO+2 , cis-MoO22+ andtrans-UO22+ exhibited different coordination geometries and charge types to result in totally nine different types of structures, all of which were characterized by single crystal X-ray diffraction. Aqueous stability, reactivity towards acid, H2O2 and bromide of vanadium complexes are studied using absorption and 51V NMR spectra. Catalytic nature of the bromination reaction by vanadium complexes has also been addressed

Synthesis, characterization and structure of Ti(IV) complexes of hydroxy-rich ligands

Coordination chemistry of two multi-hydroxy rich ligands has been explored with Ti(IV) by isolating the resultant products followed by their characterization. One of the products is also structurally characterized by single crystal XRD

Formation of mono- and di-amide-calix[4]arene derivatives from the reaction of p-tert-butyl-calix[4]arene and α-chloro-N,N-diethylacetamide in the presence of sodium hydride

The formation of mono- and di (1,2 and 1,3)-amide derivatives of p-tert-butylcalix[4]arene in the presence of sodium hydride has been demonstrated. All the compounds have been purified and characterized by various spectral methods. Both 1H and 13C NMR spectra exhibit clear-cut differences between the 1,2-di- and 1,3-di-amide derivatives

A direct fluorescence-on chemo-sensor for selective recognition of Zn(II) by a lower rim 1,3-di-derivative of calix[4]arene possessing bis-{N-(2-hydroxynaphthyl-1-methylimine)} pendants

The bis-{N-(2-hydroxynaphthyl-1-methylimine)} anchored 1,3-di-derivative of lower rim p-tert-butyl-calix[4]arene possessing a N2O2, N2O4 or N2O6 binding core was found to be selective for Zn(II) ions even at less-than-or-equals, slant60 ppb by eliciting fluorescence-on behaviour while the other ions, viz., Ti4+, VO2+, Cr3+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Mg2+, Cd2+ and Hg2+ caused no change in the fluorescence. The reaction between 1 and Zn2+ was found to be stoichiometric with the formation of a 1:1 complex; while H+ quenched the fluorescence of the complex, OH− restored it. The studies of the 1:1 isolated complexes of Zn2+, Ni2+ and Cu2+ augmented the results.© Elsevie