A new glance at ruthenium sorption mechanism on hydroxy, carbonate, and fluor apatites: Analytical and structural studies.

The sorption mechanism of Ru3+ ions on hydroxy (HAp), carbonate (CO3HAp), and fluor apatites (FAp) has been studied in detail. Ru apatites were obtained by reaction of the apatites with RuCl3 in aqueous solution. The structure and composition of the ruthenium-modified apatites were studied by several techniques: elemental analysis, XRD, EXAFS, IR, NMR, SEM-EDS, TEM, and thermal analysis. The amount of Ru in the modified apatite varies from 7.8 to 10.5 wt% and is not related to the initial composition or the specific surface area of the apatite. The different characterization techniques show that in the Ru-modified apatites Ru is surrounded by six oxygen atoms and do not contain any chlorine. For Ru-HAp and Ru-CO3HAp the new phase is amorphous whereas it is crystalline for FAp. The catalytic oxidation ability is higher for Ru-HAp and Ru-CO3HAp compared to Ru-FAp apatite in the oxidation of benzylic alcohol.

Optically active molecule-based magnets: enantioselective self-assembling, optical, and magnetic properties.

In this short communication we describe the synthesis and the optical and magnetic properties of optically active three dimensional (3D) bimetallic [Cr-Mn] networks [[Delta Cr(III) Delta Mn(II)(ox)(3)][Delta Ru(II)(bpy)(3)]ClO(4)](n)1 - Delta, [[Lambda Cr(III)Lambda Mn(II)(ox)(3)][Lambda Ru(II) (bpy)(3)]ClO(4)](n) 1 - Lambda and [[Delta Cr(III)Delta Mn(II)(ox)(3)][Delta Ru(II)(bpy)(2)p p y]](n) 2 - Delta,[[Lambda Cr(III)Lambda Mn(II)(ox)(3)][Lambda Ru(II)(bpy)(2)ppy]](n) 2 - Lambda (ox = oxalate, bpy = bipyridine, ppy = phenyl-pyridine).

Rational design of three-dimensional (3D) optically active molecule-based magnets: synthesis, structure, optical and magnetic properties of ([Ru(bpy)3](2+), ClO4(-), [Mn(II) Cr(III)(ox)3](-))n and ([Ru(bpy)2ppy](+), [M(II)Cr(III)(ox)3](-))n, with M(II) = Mn(II), Ni(II). X-ray structure of ([deltaRu(bpy)3](2+), ClO4(-), [deltaMn(II)DeltaCr(III)(ox)3](-))n and ([lambdaRu(bpy)2ppy)](+), [lambdaMn(II)lambdaCr(III)(ox)3](-))n.

To elucidate the relation between structural and magnetic properties, we have synthesized molecular materials having both Cotton effects and a ferromagnetic long range order. Such optically active 3D molecule-based magnets were rationally designed using the enantioselective template effect of optically active cations, namely Delta or Lambda [Ru(bpy)3, ClO4](+) or Delta or Lambda [Ru(bpy)3ppy](+) (bpy = bipyridine; ppy = phenylpyridine). Such cations are able to template the formation of optically active 3D anionic networks in which transition metal ions (Cr-Mn) and (Cr-Ni) are connected by oxalate ligands (ox). Following this strategy, we described the synthesis of ([Ru(bpy)3](2+), ClO4(-), [Mn(II)Cr(III)(ox)3](-))n and ([Ru(bpy)2ppy](+), [M(II)Cr(III)(ox)3](-))n with M(II) = Mn(II), Ni(II) in their optically active forms. In these 3D networks, all of the metallic centers have the same configuration, Delta or Lambda, as the template cation. We have determined the structure of ([DeltaRu(bpy)3][ClO4][DeltaMnDeltaCr(ox)3])n and ([LambdaRu(bpy)2ppy](+), [LambdaMn(II)LambdaCr(III)(ox)3](-))n by X-ray diffraction studies. These optically active networks show the Cotton effect and long-range ferromagnetic order at low temperatures. The magnetic circular dichroism of ([Ru(bpy)3](2+), ClO4(-), [Mn(II)Cr(III)(ox)3](-))n at 2 K is reported.

Cobalt-Induced C-N and C-C Bond Formation via Metal-Stabilized alpha-CF(3) Carbenium Ion.

An alpha-CF(3)-carbenium ion stabilized by a bimetallic [Co-Co] cluster was prepared and isolated in good yield, starting from the corresponding alcohol by action of HBF(4)/Et(2)O. C-N and C-C bonds with nitrogen and carbon nucleophiles could be easily formed. Subsequent decomplexation gave the free substituted beta-CF(3) alkynes in good yields.

Cobalt-complexed conjugated diyne salts: a family of rigid masked dielectrophiles. Syntheses, structures, and double nucleophilic substitutions.

A family of dicationic diyne salts of the general formula [(Co2(CO)6)2-mu,eta2,eta2-(Nu-CH2C(triple bond)C-C(triple bond)CCH2-Nu)][BF4]2 [Nu = SMe2 (3); Nu = NC6H7, 3-picoline, (5); Nu = NC9H7, quinoline (7)] were prepared and fully characterized. Three X-ray molecular structures of 3, 5, and the neutral starting material 2,4-hexadiyne-1,6-diol complex [(Co2(CO)6)2-mu,eta2,eta2-(HO-CH2C(triple bond)C-C(triple bond)CCH2-OH)] (1) are presented. Complex 1 crystallizes in the triclinic space group P1 with a = 14.722(2) A, b = 14.571(3) A, c = 14.722(2) A, alpha = 105.17(1) degrees, beta = 113.30(1) degrees, gamma = 99.20(1) degrees, and Z = 4. Complex 3 crystallizes in the monoclinic space group P2(1)/n with a = 12.758(3) A, b = 13.360(3) A, c = 20.494(3) A, beta = 91.44(1) degrees, and Z = 4, and compound 5 also crystallizes in the monoclinic space group P2(1)/n with a = 9.426(2) A, b = 21.739(5) A, c = 18.704(3) A, beta = 94.86(1) degrees, and Z = 4. The X-ray structures provide us with valuable information on the arrangement of the Co2-alkyne units, which have a cis geometry and are in sharp contrast to that observed generally for diyne-tetracobalt compounds. Complex [(Co2(CO)6)2-mu,eta2,eta2-(Me2S-CH2C(triple bond)C-C(triple bond)CCH2-SMe2)][BF4]2 (3) reacts with N-, S-, and P-centered nucleophiles and affords the related substituted complexes in high yields. The stability and reactivity of the disulfonium diyne complex 3 toward nucleophiles are compared to those of the analogous disulfonium-yne complex [(Co2(CO)6)2-mu,eta2,eta2-(Me2S-CH2-C(triple bond)C-CH2-SMe2)][BF4]2 (4).

Synthesis of cobalt carbonyl complexes of cortisol and testosterone. Study of their recognition by specific polyclonal antibodies.

We have synthesized organometallic complexes of steroids (cortisol, testosterone, dihydrotestosterone) for potential use as tracers in nonisotopic carbonyl-metal immunoassays (CMIA). An ethynyl/CO2(CO)6 fragment at the end of a five-atom spacer was coupled to position 3 of the steroid skeleton. In the case of cortisol, we exploited the difference in reactivity of the ketone and enone functions toward amines in order to form an enamine which was then made to react with carboxymethylamine to yield 3-[(carboxymethyl)oxime] steroid. Activation of the carboxylic acid function with N,N'-dicyclohexylcarbodiimide in the presence of propargylamine introduced an acetylenic function at the end of the spacer. The triple bond was then complexed by CO2(CO)8 to form complexes 5a-c. Complexes for use in CMIA should be stable in biologic media and effectively recognize specific antibodies. Complexes 5a-c were stable in the buffers we use in biochemical tests. Their cross reactivities for anti-cortisol and anti-testosterone antibodies ranged from 50 to 110% according to batch, indicating, first, that the addition of an organometallic complex in position 3 of the steroid skeleton does not hinder recognition between the organometallic steroid and antibody and, second, that their individual behavior differs substantially according to antibody batch. Although all of these complexes could be used as tracers in CMIA, it is necessary, in each case, to establish which tracer-antibody duo gives rise to the most sensitive immunoassay.

Syntheses and affinities of novel organometallic-labeled estradiol derivatives: a structure-affinity relationship.

Two series of novel estradiol derivatives, including cationic species, labeled with organometallic fragments Cr(CO)3, Cp*Ru+, or Cp*Rh2+ [Cp* = eta 5-C5(CH3)5] either in the 17 alpha-position or on the A-ring were synthesized, and their relative binding affinities (RBA) for the estradiol receptor were determined. The Ru(II) and the Rh(III) cationic derivatives were obtained as stable salts with the following counter anions (BF4-, PF6-, CF3SO3-). The satisfactory RBA values obtained for most complexes belonging to the 17 alpha series confirm that this position tolerates the presence of bulky neutral species. For instance, complex 4, in which the organometallic fragment Cr(CO)3 was attached to the phenyl ring of the 17 alpha-phenylethynyl fragment, exhibited an RBA value of 24%, very similar to that of the uncomplexed estrogen derivative 3. Surprisingly, the analogous cationic species 6 had no affinity for the estradiol receptor. This unprecedented result shows that the hormone binding site of the estrogen receptor does not tolerate the presence of a positive charge in the 17 alpha-position of the steroid. On the other hand, the alpha-face of the A-ring of estradiol did tolerate positively charged organometallic fragments bearing bulky substituents although the RBA value tended to decrease with increasing charge. The counterion in these cationic derivatives also affected binding affinity. For instance, the Ru(II) species 7a containing an CF3SO3- ion exhibited a reasonable RBA value (5.8%) compared to analogous species 13 with a PF6- ion (RBA of only 0.1%). Moreover, the triflate counteranion preserved the phenolic form of the A-ring of the estrogen derivative whereas the PF6- derivative was unstable and rapidly converted into the dienonylic form in buffer. The compared RBAs of the neutral and cationic species illustrate the preferences of the receptor hormone binding site in accepting or rejecting species of hydrophobic or hydrophilic character.

Synthesis and receptor binding of polynuclear organometallic estradiol derivatives.

Twelve novel organometallic derivatives of estradiol were synthesized with the aim of utilizing organometallic cold bioprobes as radioisotopic labels substitutes for steroid hormone receptor assays. For this purpose, we envisaged the attachment of several stable cobalt, molybdenum, osmium carbonyl clusters (tetra- and pentanuclear species) at estradiol 17 alpha-, 16 alpha-, 2- or 4-positions. The binding affinity of these new complexes for uterine estradiol receptor has been measured by the competitive binding method. The results show that the 17 alpha-position can tolerate substitution by bulky organometallic groups (especially in the case of cobalt and molybdenum carbonyl clusters). Estradiol derivatives which are functionalized at C-4 and C-16 alpha bind estradiol receptor with reasonable affinity and the RBA values are the same for the complexed and uncomplexed hormones. The 2- position is more sensitive to organometallic substitution and the complexation at the 2- alkyne results in a dramatic decrease of the RBA values. These results show that the attachment of polynuclear moieties in estradiol 17 alpha-, 4- and 16 alpha-, positions gives rise to compounds which are of potential utility in a new non-radioisotopic receptor assay since the metal-carbonyl markers are readily detected by high-sensitivity Fourier-transform infra-red spectroscopy.