Dinuclear compounds structure

The distorted pentagonal-pyramidal coordination has been identified also in Mo and W oxo diperoxo siloxane complexes64 (14-17). Crystal structures for species 14, 15 and 16 have been solved, while for the tungsten dinuclear compound, structural identification was suggested on the basis of similar IR and Raman spectra obtained for complexes 16 and 1764. 

First examples of complexes of a,cj-digold alkylidenes have been prepared in moderate yields from the corresponding di-Grignard reagents with 2 equiv. of (Ph3P)AuBr as colorless, crystalline products. The structure of the dinuclear compound with the -(CH2)4- spacer has been determined (Equation (3)).19 Preparative efforts oriented at the synthesis of the analogous ethane, propane, and hexane derivatives were unsuccessful. 

The most straightforward synthesis of compounds (L)AuAr uses the metathesis of (L)AuX precursors with aryllithium reagents, as, for example, executed for the preparation of (Ph3P)AuPh. The crystal structure of this benchmark complex has been determined. The linear coordination geometry is as expected. No aurophilic contacts are discernible in the crystal packing. Short Au- -Au contacts are observed, however, in the dinuclear compound (dppm)(AuPh)2 with an intramolecular intermetallic distance of 3.154(1) A. This complex shows a UV-VIS absorption at 290-300 nm and is luminescent in fluid solution at room temperature.1... 

Abstract This review deals with spin crossover effects in small polynuclear clusters, particularly dinuclear species, and in extended network molecular materials, some of which have interpenetrated network structures. Fe(II)Fe(II) species are the main focus but Co(II)Co(II) compounds are included. The sections on dinuclear compounds include short background reviews on (i) synergism of SCO and spin-spin magnetic exchange (ii) cooperativity (memory effects) in polynuclear compounds, and (iii) the design of dinu-... 

In conclusion, the presented dinuclear iron structure is the first example of a bio-mimetic iron compound, which can be regarded as a first generation model for the class of [Fe]-only hydrogenases. The complex incorporates both relevant carbon monoxide ligands, as well as three bridging thiolato ligands, which could be possibly present in the active site of these enzymes. 

Some selected reactions of 21b were investigated [32]. In the reaction with [(Ph 0)4W=0j the dinuclear compound 24 is formed (Eq. 16) containing an almost planar W2OP four-membered ring system. The structure of 24 reveals that after the formal cycloaddition reaction a reductive W-W bond formation occurs under loss of OPh moieties. 

The Tc complex [TcI(N—Ar)s] (28) (see Section 5.2.2.1.2) can be reduced with Na° in THE to yield the green, nonbridged, dinuclear compound [Tc2(NAr)6] (46), in which three imido-ligands are bound to the Tc center and connected by a single bond to the second technetium. The molecule has a staggered, ethane-like structure and is diamagnetic. Reduction of (28) yields another homoleptic imido-complex of Tc, the imido-bridged, tetrahedral, dinuclear compound [Tc2(/u-NAr )2(NAr )4] (47) (Ar = 2,6-diisopropylphenyl). The conformation could be confirmed by X-ray structure analysis the assumption of a Tc Tc bond is confirmed by the... 

A hither facet of research has involved the structural characterisation of aluminium complexes which incorporate polydentate salen-type ligands. These have been noted in both neutral and monocationic (ion-separated) contexts (the latter requiring that the metal centre be stabilised by an external Lewis base) [35]. While such charged systems are invariably mononuclear the same is only usually true of their neutral analogues by virtue of the sterically demanding bis(aryloxide), chelating ligand. In the context of these latter complexes, dimerisation has been noted [251] while, more recently, the employment of flexible alkyl chains between two salen-coordinated aluminium ions has enabled the observation of dinuclear compounds [160, 161]. 

The structural chemistry of Au-Pt bond or interaction-containing compounds is by far better exemplified in the literature. Dinuclear compounds with the Au( t-H)Pt... 

The molecular structures of four dinuclear compounds containing the p-hexafluorocyclooctatrieneyne ligand are shown in Fig. 18 (799). Selected average geometrical features of the fluorinated rings in these four structures,... 

The Mn complexes of dicarboxylic acids are efficient catalase mimics. The crystal structure of [MnII(ri1ri1-L4)(phen)2] 28, (L4 = cA-5-norbomene-e cfo-2,3,-dicarboxylic acid and phen = 1,10-phenanthroline) (Figure 13) shows that this complex is a water linked dinuclear compound in solid state [100n],... 

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