Di nuclear

The new arsino(phosphino)methanes with bulky substituents at the two donor centers can behave both as chelating and bridging ligands toward palladium(II). Besides neutral and mono- as well as di-nuclear cationic compounds, in which these ligands are bonded in a chelating fashion, a di-nuclear complex of the A-frame type could also be generated (see Scheme 5).396... 

During the investigations leading to the determination of these structures, another compound, containing a carbonate-bridged di-nuclear anion, was obtained (217), whose structure is shown in Fig. 

The models proposed for the Ru(III) and Ru(EDTA) catalyzed epoxidation of allyl alcohol replace each other in the corresponding reactions of cyclohexene. Thus, mono-nuclear and di-nuclear paths were reported for the Ru(III) and Ru(EDTA) catalysis, respectively (145,146). 

Fig. 8. Oxygen-17 NMR spectra at pH = 1.3, illustrating the formation of the di-nuclear complex at 25°C after (a) 3 min, (b) 1 h and (c) 6 h of mixing [Re02(CN)4]3 and H2170. The total complex concentration [Re] = 0.2 m, /m = 1.0 m (KN03), NMR chemical shift reference is the nitrate ion (<5(N03) = 413 ppm) (5). (Adapted with permission from Roodt, A. Leipoldt, J. G. Helm, L. Merbach, A. E. Inorg. Chem. 1992, 31, 2864-2868. Copyright 1992 American Chemical Society).

Catalysis by Metal and Oxide Nanoparticles, Single Metal Atoms and Di-Nuclear Oxo-Ions in Zeolites... 

Mn2(CO)g(PH3)] has been prepared by the reaction between Mn2(CO)33, and PH3 in hexane-benzene under u.v. irradiation. I.r. evidence indicates that the phosphine ligand is equatorial.The reaction between Mn2(CO)j3, and PPhg has been re-investigated under a variety of conditions. Both mono-and di-nuclear products have been isolated and. by carrying out the reaction... 

Oxidative addition of organic azides to low valent species, mainly in oxidation state +III, was found to be a general method for obtaining pentavalent mono- or di-nuclear nitrene derivatives.294 Applied to Nb1 compounds, it led to the first dinitrene compound. 

One class of complexes, that of substituted catecholate ligands, has yielded a variety of mono- and di-nuclear MoVI complexes. Mo(CO)6 reacts with the oxidized form of the 3,5-di-ferf-butylcatechol (i.e. 3,5-di-rerr-butyl-l,2-benzoquinone) to yield Mo(dbcat)3 which reacts with 02 to give the dinuclear complex [MoO(dbcat)2]2.373 In contrast, reaction of Mo(CO)6 with 3,4,5,6-tetrachloro-l,2-benzoquinone yields the dinuclear non-oxo complex Mo2(02C6Cl)6.3S7 The complex Mo2Os(phenSQ) has already been discussed.363 This complex... 

The coordinatively unsaturated complexes [M(CO)i(hfN)]2 are extremely reactive. With polydentate N and P ligands, new mono- or di-nuclear bridged mixed-ligand complexes are formed by fission of the CO bridges. Examples are given in Table VII (171, 172). 

Due to low solubility in hydrocarbon solvents at low temperatures, [(>75-C5H5)Mo(CO)3]2 is not well suited for photoreactions. In order to increase the solubility, the methylcyclopentadienyl derivative, [(t/5-CH3C5H4)-Mo(CO)3]2 (102), has been used. After photoreaction with la-lc and It in n-pentane solution, the reaction mixtures contain two products each, di-nuclear tricarbonylbis(f/5-methylcyclopentadienyl)( /4-diene)molybdenum (103) and dicarbonyl-t -enyl- 5-methylcyclopentadienylmolybdenum complexes (104) (141) [Eq. (56)]. 

Synthesis of both mono- and di-nuclear complexes of Pd and Pt with (SCF3) has been reported.46,47 Mononuclear species have been obtained by oxidative addition of (SCF3)2 to the [M(PPh3)4] (M = Pd or Pt) complexes, and by metathetical reactions (equation 12). 19F N.m.r. was used to establish the trans-influence series... 

Despite the differences in mechanism, the expectation that thiolate ligands will act as nucleophiles appears to be a feature of the oxidation of [Ni(L)CN] by 02. The strong tendency of Ni thiolates to form dimers and higher polymers (80, 92-94) and the fact that the presence of a tightly bound anionic ligand appears to be required to cleave the di-nuclear complexes (e.g., CN or thiolate (85)) is evidence of the nu-cleophilicity of terminal thiolate ligands in planar Ni(II) complexes. 

The final iron cage discussed is the largest known ferric wheel. The octadecanuclear wheel, [Fe(0H)(XDK)Fe2(0Me)4(02CMe)2]e (70) [XDK = the dianion of m-xylylenediamine bis(Kemp s triacid imide) see Scheme 2] (164), shown in Fig. 29, is made from reaction of the di-nuclear iron complex of XDK with [NEt4](02CMe) in methanol, followed... 

Recently Holm and co-workers (131) have described a new OAT reaction system that cycles between (L-NS)2Mo 02 (Fig. 10b) and (L-NS)2Mo 0 (Fig. 12). The steric hindrance of the two bulky p-tert-butylphenyl groups prevents comproportionation [Eq. (15)] to form di-nuclear [Mog Os] centers (37). This reaction system is thermodynamically competent to oxidize or reduce all enzymatic substrates except those requiring the [Mo OS] center as oxidant. The system is stable in the presence of strong oxo donors, such as MesNO and 104. The kinetics of substrate oxidation are second order and sensitive to substrate, indicating a different mechanism than the previously studied system based upon (L-NS2)Mo02 (130). 

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