Naphthalenes ligand

Complexation with polyaromatic systems has also been observed. For instance, Mlnaphthalenelj, M = Cr (88,183), Mo (183), V (183), or Ti (183) may be synthesized in a solution reactor with the appropriate, metal vapors at liquid-nitrogen temperature. The Cr/naphthalene complex is less stable (dec. 160°C) than CrtCsH ) (m.p. 283-284° C). In fact, the naphthalene ligand is sufficiently labile to allow reaction under mild conditions, to afford CrL (L = CO or Bu NC), or Cr(naphth)Ls [L = PFj, P(OMe)3, or PMea]. The Mo, V, and Ti species are equally reactive. Analogous 1-methylnaphthalene complexes were also isolated (183). In addition, the complexes shown in Fig. 38 were synthesized by reaction, at the temperature of liquid nitrogen, of Cr atoms with 1,4-diphenylbutane (35, 201, 202). Analogous complexes were formed with 1,5-diphenylbutane (202). 

The first reported interaction between a C—H bond in a ligand and a soluble transition metal complex was that reported by Chatt and Davidson (5). The reaction product from the reaction of sodium naphthalene with (rans-dichlorodi-(dmpe)ruthenium(II) (I) (dmpe = 1,2-bisdimethylphosphinoethane) was found to be a tautomeric equilibrium mixture of the ruthenium(O) complex (II) that contains a 7r-complexed naphthalene ligand and the ruthenium(II)-hydrido complex (III) where a C(2)—H bond has added to the ruthenium ... 

Yous, S., Andrieux, J., Howell, H. E., Morgan, P. J., Renard, P, Pfeiffer, B., Lesieur, D., Guardiola-Lemaitre, B. Novel naphthalenic ligands with high affinity for the melatonin receptor. J. Med. Chem. 1992, 55(8), 1484-1486. 

Two different binuclear copperdi) complexes have been prepared recently, one with a bridging phenoxy ligand having two bis-benzi-midazole arms (12, Fig. 14), and the second having a bis-cyclen-naphthalene ligand (13, Fig. 15) (352, 353). Both of them show bimetallic cooperativity for the hydrolysis of phosphate diesters, contrary to studies with the dinuclear cobalt complex (354). The pseudo-first-order rate constants for hydrolysis of the para-nitrophenylphosphate ester of propylene glycol by bis-benzimidazole-based copper complexes... 

The diiodides Dyl2 and Ndl2 (but again not Tmh) cleanly react with naphthalene in DME or THF. In the case of dysprosium, a trivalent complex [(CioH8)DyI(DME)] could be structurally characterised, in which the naphthalene ligand which is ty -bonded to dysprosium is in the dianionic form (Evans et al., 2000) (Figure 3). 

With the 1,4-dimethoxy naphthalene ligand, cyano-stabilized anions (including cyanohydrin acetal anions) and ester enolates equilibrate even at low temperature and strongly favor addition at the a-position (C-5). The kinetic site of addition is also generally C-a. However, the 2-lithio-l,3-dithiane anion and phenyllithium do not equilibrate over the temperature range —78 to 0°C. The sulfur-stabilized anions favor addition at C-/3 (equation 119), while phenyllithium gives a mixture favoring C-a (equation 120). 

The arene ligands are displaced only with difficulty CO or PFj yield Cr(CO) or Cr(Pp3)g respectively at 200°C/300atm. pressure. Bis(naphthalene)chromium, made by metal atom synthesis, is much more labile. Two naphthalene ligands are readily displaced by 6RNC or 3bipy, and one by 3CO, 3PF3 or 3PR3. 

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