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Tris , anionic adducts

Another case of bridging reported recently is in the series of anionic adducts 54-56 with methylene-bridged tri- and tetra-tin framework214. [Pg.996]

Figures 2,3,5, and 6 show anionic compounds 5 to 22 and 25 to 30, which have been described in the literature since 1997. In these adducts, as in examples 1 to 4, the P(VI) derivatives have carbon or oxygen atoms in the immediate proximity of the central (pseudo-)octahedral atom. This is probably due to the accessibility of the ligand precursors, the ease of their manipulation and, more importantly, to the sheer strength of the resulting P-C and P-0 bonds. They all present tris(bidendate) structures in which the three chelating rings can be identical (Fig. 2 and most of Fig. 6) or of two different types (Fig. 3). The ligands can be monooxo (Fig. 6) or dioxo (Fig. 2 and Fig. 3). These differences in composition have, of course, consequences for the making of the derivatives. Figures 2,3,5, and 6 show anionic compounds 5 to 22 and 25 to 30, which have been described in the literature since 1997. In these adducts, as in examples 1 to 4, the P(VI) derivatives have carbon or oxygen atoms in the immediate proximity of the central (pseudo-)octahedral atom. This is probably due to the accessibility of the ligand precursors, the ease of their manipulation and, more importantly, to the sheer strength of the resulting P-C and P-0 bonds. They all present tris(bidendate) structures in which the three chelating rings can be identical (Fig. 2 and most of Fig. 6) or of two different types (Fig. 3). The ligands can be monooxo (Fig. 6) or dioxo (Fig. 2 and Fig. 3). These differences in composition have, of course, consequences for the making of the derivatives.
Zinc dithiocarbamates have been used for many years as antioxidants/antiabrasives in motor oils and as vulcanization accelerators in rubber. The crystal structure of bis[A, A-di- -propyldithio-carbamato]zinc shows identical coordination of the two zinc atoms by five sulfur donors in a trigonal-bipyramidal environment with a zinc-zinc distance of 3.786 A.5 5 The electrochemistry of a range of dialkylthiocarbamate zinc complexes was studied at platinum and mercury electrodes. An exchange reaction was observed with mercury of the electrode.556 Different structural types have been identified by variation of the nitrogen donor in the pyridine and N,N,N, N -tetra-methylenediamine adducts of bis[7V,7V-di- .vo-propyldithiocarbamato]zinc. The pyridine shows a 1 1 complex and the TMEDA gives an unusual bridging coordination mode.557 The anionic complexes of zinc tris( V, V-dialkyldithiocarbamates) can be synthesized and have been spectroscopically characterized.558... [Pg.1196]

Heterocyclic nitrogen donors and their adducts with zinc chloride have been studied.623,624 A large number of other ligand systems have also been characterized, for example, zinc halide adducts of 2,2-dimethylpropane-1,3-diamine and hexamethylphosphoramide have been studied.625,626 The formation of mixed ligand complexes with chloride and substituted pyridines has been studied.627 The zinc tris(pyridyl) chloride anion has also been structurally characterized.628 Manganese(II) ions have been used to probe the stereochemistry in reactions of zinc halides with pyrazine.629... [Pg.1201]

Alternatively, Ballini devised a new strategy to synthesize tri-alkylated pyrroles from 2,5-dialkylfurans and nitroalkanes <00SL391>. This method involves initial oxidation of 2,5-dimethylfuran with magnesium monoperoxyphthalate to cA-3-hexen-2,5-dione (6). Conjugate addition of the nitronate anion derived from the nitro compound 7 to 6 followed by chemoselective hydrogenation of the C-C double bond of the resulting enones 8 (obtained by elimination of nitrous acid from the Michael adduct) completes the conversion to the alkylated y-diketones 9. Final cyclization to pyrroles 10 featured improved Paal-Knorr reaction conditions involving reaction of the diketones with primary amines in a bed of basic alumina in the absence of solvent. [Pg.112]

This point is borne out by the structure of tris indenyl samarium (5d). An earlier report of the nmr spectrum was interpreted as evidence of covalent bonding in the tetrahydrofuran adduct of samarium triindenide 66). Indenyl anion. [Pg.45]

By the stepwise thermal decomposition of the tris chelate, mono adducts of the type [NiX2(N—N)] (X = halides, NCS) were obtained.852-854 These complexes are polynuclear six-coordinate with bridging anions. In the thiocyanato derivative the nickel atoms are ferromagnetically coupled. [Pg.81]

It has been shown that mononuclear cobalt superoxo complexes react with 2,4,6-tri-t-butyl-phenol. The anion [Co(CN)5(02)]3 acts as a base in the oxidation of the phenol. The neutral complex Co(salptr)(Oz) forms a peroxy adduct with 2,4,6-tri-t-butylphenol. An X-ray study on this adduct has revealed the structure shown in (10).m... [Pg.329]

When the anions 287 derived from compounds 285 were allowed to react with tri-alkylboranes, followed by oxidation, the expected ketones were obtained455. A similar process is described in Scheme 40 for bis(phenylsulfanyl)alkyllithiums151,152. Successive treatment of the obtained trialkylborane adducts 288 with mercury(II) chloride and hydrogen peroxide yielded tertiary alcohols (Scheme 75)456. The last reactions failed with bis(phenylsulfanyl)alkyllithiums. [Pg.186]


See other pages where Tris , anionic adducts is mentioned: [Pg.458]    [Pg.134]    [Pg.185]    [Pg.36]    [Pg.446]    [Pg.334]    [Pg.334]    [Pg.554]    [Pg.1248]    [Pg.156]    [Pg.11]    [Pg.845]    [Pg.315]    [Pg.289]    [Pg.422]    [Pg.69]    [Pg.25]    [Pg.178]    [Pg.563]    [Pg.212]    [Pg.164]    [Pg.1063]    [Pg.161]    [Pg.491]    [Pg.125]    [Pg.59]    [Pg.82]    [Pg.83]    [Pg.312]    [Pg.588]    [Pg.729]    [Pg.996]    [Pg.1149]    [Pg.334]    [Pg.334]    [Pg.290]    [Pg.167]    [Pg.25]   
See also in sourсe #XX -- [ Pg.446 , Pg.447 , Pg.448 ]




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Tris adducts

Tris anion

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