Ethylene/ruthenium interaction

The chemistry of the 1 1 and 1 2 complexes differs with respect to hydrogenation (84,89). The 1 2 derivatives are inert to hydrogenation, while the 1 1 compounds are smoothly transformed into an ethylidene complex (see Scheme 1). This difference in behavior may well reflect the cause of differences in behavior of olefins on metal surfaces toward hydrogenation. The ethylidene complex may be converted back to the olefin adduct by reaction with trityl ion. The ethylidene adduct was first obtained for ruthenium by interaction of ethylene with H RujfCO) (89), and is structurally related to the corresponding cobalt derivatives, Co3(CO)9RC. As discussed above, the structure has been established in detail and involves a capping of the metal triangle... 

This type of receptor is represented by compounds 16a,b bearing ruthenium ) bipyridine moieties. Both calixarenes [18] exhibit 1 1 binding of chloride and bromide anions (DMSO-d6), and they are especially suitable for the complexation of H2POj (X16a=2.8-104 M-1 K16b=5.2 103 M"1). On the other hand, if we compare these results with those for similar non-calixarene receptors, where the bipyridine unit is substituted by alkyl, aryl or ethylene glycol substituents, the introduction of calixarene does not bring any substantially new features into the complexation abilities of these derivatives. As shown by X-ray analysis, the anion is encapsulated within the cavity formed by amidic functions with the contributions of CH...anion interactions from the bipyridine unit. 

H NMR spectra (DMSO-dg) of the Ag" complexes of ruthenocenophanes (81) and (82) suggest no interaction between the ruthenium and the complexed silver ion. In this case, the methylene protons attached to sulfur atoms were shifted more than the protons of the ruthenocene nucleus. H NMR spectra of the mercury(II) complexes of (80)-(82) suggest that there is signihcant interaction between ruthenium and the mercury(II). The P protons of the Cp rings were shifted further downfield than the a protons, and the ethylene protons exhibited very little downfield shift <85BCJ3540>. 

Ruthenium arenes are another interesting class of organometallics with proven anticancer activity. The most active complex [( 7 -biphenyl)Ru(ethylene-diamine)Cl] 1 (Scheme 11) had an activity comparable to Garboplatin against a human ovarian cancer cell line. " The interaction of this compound with different biomolecules has been studied, and again, DNA has been suggested as the primary target. It is, however, unclear at present... 

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