An overview on the developments of zirconium phosphate (ZrP) and its organic derivatives in heterogeneous catalysis in recent years is reported in the present review. Two basic aspects have been emphasized: first, the catalytic properties of zirconium phosphates were discussed, with particular attention to the effect of surface acidity and hydrophobic/hydrophilic character, textural properties,...

We report results of simulations on the formation of simple zirconium iodide molecules. Previous work by Wimmer et al. [1] explored the relationship between iodine and a zirconium surface. We investigate the reaction schemes through atomistic simulations to better understand the nature of Zr-I interactions through isolated molecules. The computed energy values of varying Zr-I systems suggests a...

Stereochemical investigations have shown that the conversion of 2-hydroxyethylphosphonate to hydroxymethylphosphonate by the enzyme HEPD involves removal of the pro-S hydrogen at C2 and, surprisingly, the loss of stereochemical information at C1. As a result, the mechanisms previously proposed for HEPD must be re-evaluated.

Supramolecular bidentate phosphite ligands are presented as a new class of ligands for rhodium catalysed asymmetric hydrogenation.

AIMS To report the appearances of zirconium dioxide and barium sulphate in interface membranes, synovium, and other tissues around joint prostheses. METHODS Histological sections from 23 specimens were reviewed by light microscopy and polarisation. Scanning electron microscopy and x ray microanalysis were performed on routinely processed paraffin wax sections. RESULTS Polyethylene, metals, ...

The mechanical properties and good biocompatibility of zirconium and some of its alloys make these materials good candidates for biomedical applications. The attractive in vivo performance of zirconium is mainly due to the presence of a protective oxide layer. In this preliminary study, the surface of pure zirconium modified by anodisation in acidic media at low potentials to enhance its barrie...

A novel, convenient and efficient multi-component reaction for synthesis of phosphonate derivatives from activated acetylenic compounds with 2-hydroxyacetophenone in the presence of phosphites in water lead to the formation of phosphonates in good yields.

The stable phosphonate derivatives have easily synthesized by the reactions involving trialkyl(aryl) phosphites and dimethyl acetylenedicarboxylate in the presence of 4-nitrophenol and/or acid chlorides, dialkyl(aryl) phosphites and N-methylimidazole at 70 oC under solventfree conditions.

The synthesis of adenine and thymine cyclopentylethyl nucleosides is presented. This novel constrained monomeric building block is very difficult to incorporate into oligonucleotides. It was introduced in 13mer oligodeoxynucleotide sequences at a single position using H-phosphonate chemistry. Phosphoramidite chemistry completely failed in this particular case. The H-phosphonate building blocks ...