We report here a practical and efficient synthesis of α-aminophosphonic acid incorporated into 1,2,3,4-tetrahydroquinoline and 1,2,3,4-tetrahydroisoquinoline heterocycles, which could be considered to be conformationally constrained analogues of pipecolic acid. The principal contribution of this synthesis is the introduction of the phosphonate group in the N-acyliminium ion intermediates, obtai...

A syntheses of three new muramyl dipeptide (MDP) analogues related to LK 423 as potential immunomodulators are presented. The dipeptide part of the lead compound was modified by introducing a phosphonamide isostere instead of the amide bond between Lalanine and D-glutamic acid (or D-isoglutamine), yielding new MDP analogues 5 and 9. Furthermore, the amide bond between L-Ala and D-Glu was replac...

The X-ray structural characterization of tritylphosphonic acid, Ph3CPO3H2 (), reveals that it possesses three different structural forms (a hexameric cage, a two-dimensional polymeric sheet and a dimer) depending upon the solvent used for crystallization. The reaction of cerium nitrate with under solvothermal conditions afforded a molecular dinuclear Ce(III) phosphonate, [Ce2{Ph3CPO2(OEt)}4(NO3...

TiO2/ZrO2 nanocomposite was obtained by the sonochemical technique. In this method, two separate gels containing zirconium and titanium were prepared and mixed together. The precursor sol of zirconium was prepared from an aqueous solution of ZrCl4. The precursor titanium tetra isopropoxide (TTIP) dissolved in isopropanol. Mixing of Titanium and Zirconium gels was resulted in a yellow TiO2/ZrO2 ...

TiO2/ZrO2 nanocomposite was obtained by the sonochemical technique. In this method, two separate gels containing zirconium and titanium were prepared and mixed together. The precursor sol of zirconium was prepared from an aqueous solution of ZrCl4. The precursor titanium tetra isopropoxide (TTIP) dissolved in isopropanol. Mixing of Titanium and Zirconium gels was resulted in a yellow TiO2/ZrO2 ...

Zirconium oxide (ZrO2) has generated wide interest because of its potential in applications such as solid oxide fuel cells, catalysts and optical devices. In these applications, it is important to control the grain size of the material and increase the surface area by introducing porosity with tailored pore size. This paper presents a synthesis route for the preparation of mesoporous zirconia u...

The increase of aesthetic demands, together with the successful outcome of current implants, has renewed interest in the search for new materials with enough mechanical properties and better aesthetic qualities than the materials customarily used in implanto-prosthetic rehabilitation. Among these materials, zirconium has been used in different types of implants, including prosthetic abutments. ...

In mouse spleen cells, the effects of chloroplatinic acid and zirconium oxychloride on IgM antibody production against sheep red blood cells (SRBC) were studied in vitro. The following conclusion were drawn from this study: 1. Chloroplatinic acid suppressed direct plaque formation against SRBC in mouse spleen cells in vitro. 2. The viability of mouse spleen cells, to which chloroplatinic acid w...

Salt metathesis reactions of Cp(2)(NR(2))ZrX (X = Cl, I, OTf) and lithium hydrosilazides ultimately afford hydride products Cp(2)(NR(2))ZrH that suggest unusual β-hydrogen elimination processes. A likely intermediate in one of these reactions, Cp(2)Zr[N(SiHMe(2))t-Bu][N(SiHMe(2))(2)], is isolated under controlled synthetic conditions. Addition of alkali metal salts to this zirconium hydrosilazi...

Zirconium amides have become increasingly popular and useful due to their widespread use as precursors to other zirconium complexes and their use in the production of solid oxide fuel cells (SOFCs). Herein we report the mol-ecular structure of tris-(di-methyl-amido)-bis-(di-methyl-amine)-zirconium(IV) iodide, [Zr(C2H6N)3(C2H7N)2]I. The bond lengths and bond angles are consistent with a slightly...