A hydroxyapatite and two apatites enriched with alumina have been synthesized to support NiMo sulfide. Hydroxyapatites are efficient supports of NiMo sulfide catalyst for desulfurization of thiophene. Addition of A] ions during the preparation results in an intimate mixture of crystalline apatite and amorphous AlPO4. This leads to an important increase in surface area and porous volume that is beneficial to the catalytic activity. The highest activity is obtained with calcium-deficient apatite because the presence of apatitic HPO42- groups or related surface defects is required to improve the dispersion of the Mo ions in the oxidic precursor. The apatitic catalysts are superior to commercial NiMoP/Al2O3 catalysts, which makes NiMo/apatite a good candidate for hydrotreating.

Supports based on apatite and apatite weakly enriched with zirconium phosphate were synthesized. On these supports, NiMo sulfides were transplanted. The NiMo/Apatites catalysts convert selectively the dimethyldisulfide (DMDS) to methanthiol contrary to their counterpart NiMo/Al 2 O 3 . Adding low amounts of zirconium ions improves the catalytical activity. The activity improvement is due to the increase of surface area, as well as to the good dispersion of the NiMo sulfide phase.

The Knoevenagel condensation of benzaldehyde with ethyl cyanoacetate was performed in different solvents, at room temperature, in the presence of as-synthesized and Al-enriched fluoroapatites and hydroxyapatites as catalysts, and, for comparison, in the presence of a magnesium oxide and a mixed magnesium–aluminium oxide. The catalytic activity is significantly improved for the Al-enriched fluoroapatites and hydroxyapatites compared to their as-synthesized precursors. However, the highest activity is observed for the magnesium oxide and the mixed magnesium–aluminium oxide where the reaction is nearly complete within 15 min in the absence of diffusion limitation at the external surface. The higher activity of magnesium-based oxides can be explained by the differences in the nature of the active sites. MgO possesses principally isolated O2− sites, whereas the mixed oxide would possess Mg2+–O2− and Al3+–O2− acid–base pairs. The presence of Al3+–O2− pairs might also been postulated to account for the higher activity of Al-enriched hydroxyapatite and fluoroapatite, the higher activity being reinforced by the presence of superficial HPO42− basic species in the hydroxyapatite series. When the reaction is carried out in methanol as solvent, it was shown that transesterification of ethyl cyanoacetate into methyl cyanoacetate and trans-α-ethyl-2-cyanocinnamate into trans-α-methyl-2-cyanocinnamate may occur in the presence of strongly basic catalysts.

A series of Ca-deficient and Co-containing hydroxyapatite samples, noted Ar and Cx, respectively, where r is the total Ca/P molar ratio (r=1.46–1.62) and x the Co wt%, were prepared by precipitation in aqueous media. The catalytic activities of CoMo/Ar and Mo/Cx sulphided catalysts have been examined for the S–S bond hydrogenolysis of dimethyldisulphide (DMDS) under relatively mild operating conditions (200°C, 1 atm). The overall activity depends on the Co depositing mode and the hydroxyapatite carrier Ca/P molar ratio. Depositing Co by impregnation on hydroxyapatite samples with low Ca/P molar ratios involves an increase of the catalytic activity until approaching that corresponding to CoMo/Al2O3 catalyst. This can be attributed probably to a better dispersion of the CoMo sulphided catalysts on apatitic carrier with low Ca/P molar ratios. DMDS is selectively reduced to CH3SH on the CoMo/A1,46 sulphided catalyst than on the CoMo/Al2O3 one, even at conversions as higher as 100%.

We have prepared a series of catalysts combining cobalt and a hydroxyapatite by coprecipitation in a basic medium. These sulfided solids catalyse the hydrodesulfurization of dimethyldisulfide at 360 degrees C and its hydrogenolyzis into CH3SH at 200 degrees C. The coprecipitated solids are found more active than the impregnated catalysts because they exhibit a better dispersion of the active Co-S phase at higher Co content. With the precipitated catalysts, Co ions substitute for Ca ions into the apatite structure, The formation of large sulfide particles is thus more difficult as a result of sulfiding because the Co ions have to move to the surface. The apatite catalysts are intrinsically. as active as their homologous Co/Al2O3.

The optimal structures of a series of α-arylpropionic acids with anti-inflammatory activity are established by using the semi-empirical quantum mechanical procedures, AMI and AMSOL, in the gas phase and in water solution, respectively. In these calculations, the arylpropionic acids are considered in their neutral and ionized forms. As expected, these compounds exhibit two preferred conformations in which the α-hydrogen atoms of the propionic acid group lies approximately in the plane of the central aryl ring. The deprotonation energies are then determined as the difference between the formation energies of the protonated and deprotonated forms. A Quantitative Structure Activity Relationship (QSAR) study reveals that only the gas phase results compare to some extent favorably with the anti-inflammatory activity. As expected, the smaller the deprotonation energy, the larger the anti-inflammatory activity. Satisfactory relationships between the in vivo activities and deprotonation energies, the HOMO energies and lipophilicities were found.

The reaction of the 3,6-bis (2′-pyridyl) pyridazine (dppn) ligand, with one and two equivalents of [Rh (CO) 2Sn] (PF6) , (s = THF) , yields respectively the mononuclear complex [Rh (CO) 2 (dppn) ] (PF6) 1 and the binuclear complex [Rh2 (CO) 4 (dppn) ] (PF6) 2 3. Furthermore, the reaction of 1 with PPh3 results in a substitution reaction to give [Rh (CO) (dppn) (PPh3) 2] (PF6) 2. The unsaturated complex 3 reacts with the monodentate phosphine PPh3 to yield a mixture of the known compound [Rh (CO) 2 (PPh3) 2] (PF6) and of the mononuclear [Rh (CO) (dppn) (PPh3) ] (PF6) 4, the crystal structure of which was established by X-ray diffraction. Moreover, 3 reacts with the bis (diphenylphosphino) methane (dppm) ligand in a 1 : 2 ratio to form the binuclear A-frame complex [Rh2 (CO) 2 (dppn) (μ-dppm) 2] (PF6) 2 5. However, the reaction of 3 with excess dppm (1 : 4 ratio) gives the known complex [Rh (CO) (dppm) 2] (PF6) 6.

A series of PNP-ruthenium(II) complexes Ru(OCOMe)(2)(PNP) (1), Ru(OCOMe)(2)(PNP)(PPh3) (2), the monohydrides RuHX(PNP)(PPh3) (X = OCOMe (3); X = Cl (4)), and dihydride RuH2(PNP)(PPh3) (5) (PNP = 2,6-bis(diphenylphosphinomethyl)pyridine) were synthesized and characterized by microanalysis as well as NMR, IR, and mass spectroscopies. The solution dynamics of complex 1 were studied by variable-temperature H-1 and P-31{H-1} NMR spectroscopies. The crystal structure of RuHCl(PNP)(PPh3) (4) was determined by X-ray crystallography, showing that the PNP ligand coordinates the Ru atom in a meridional mode. The hydride complexes RuH(OCOMe)(PNP)(PPh3) (3) and RuH2(PNP)(PPh3) (5) undergo deuterium exchange reactions with CD3OD to give substitution of both the hydrides and PNP methylene protons by deuterium. The probable intermediates involved in these exchange processes are molecular dihydrogen complexes of Ru(II).

Ni, Mo and the NiMo association were introduced in a stabilized HY zeolite. The modifications of the solids following sulfidation were examined by various techniques. We showed that metal sulfides are built up inside the zeolite. In most cases, sulfidation of the metals is incomplete. Full sulfidation is obtained only for the Ni zeolite processed with pure H 2 S and for the Mo zeolite when the Mo amount is very low. In the NiMo zeolite, Ni and Mo sulfidations are nearly additive. From XPS, Ni on the oxidized samples concentrates near the zeolite surface; it becomes better dispersed upon sulfidation. Mo is well dispersed in both oxidized and sulfided states. Ni dispersion is improved when combined with Mo. Zeolite OH bands connected with acidity were examined by FTIR. Introduction of either metal strongly decreases the Brönsted acidity. This acidity is regenerated upon sulfidation for the Ni and NiMo zeolites but not for the Mo zeolite. Changes in Lewis acidity are also observed.