Interactions metallic

Bimetallic Complexes. There are two types of bimetaUic organometaUic thorium complexes those with, and those without, metal—metal interactions. Examples of species containing metal—metal bonds are complexes with Ee or Ru carbonyl fragments. Cp ThX(CpRu(CO)2), where X = Cl or 1, and Cp7Th(CpM(CO)2), where M = Ee or Ru, have both been prepared by interaction of CP2TI1X2 or Cp ThCl [62156-90-5] respectively, with the anionic metal carbonyl fragment. These complexes contain very polar metal—metal bonds that can be cleaved by alcohols. 

S. Bresadola, in R. N. Grimes, ed.. Metal Interactions with Boron Clusters, Plenum Press, New York, 1982. 

When this ratio is larger than 0.59, as in the Group 7—10 metals, the stmeture becomes more complex to compensate for the loss of metal—metal interactions. Although there are minor exceptions, the HAgg rule provides a useful basis for predicting stmeture. 

The dipole density profile p (z) indicates ordered dipoles in the adsorbate layer. The orientation is largely due to the anisotropy of the water-metal interaction potential, which favors configurations in which the oxygen atom is closer to the surface. Most quantum chemical calculations of water near metal surfaces to date predict a significant preference of oxygen-down configurations over hydrogen-down ones at zero electric field (e.g., [48,124,141-145]). The dipole orientation in the second layer is only weakly anisotropic (see also Fig. 7). 

The orientational structure of water near a metal surface has obvious consequences for the electrostatic potential across an interface, since any orientational anisotropy creates an electric field that interacts with the metal electrons. Hydrogen bonds are formed mainly within the adsorbate layer but also between the adsorbate and the second layer. Fig. 3 already shows quite clearly that the requirements of hydrogen bond maximization and minimization of interfacial dipoles lead to preferentially planar orientations. On the metal surface, this behavior is modified because of the anisotropy of the water/metal interactions which favors adsorption with the oxygen end towards the metal phase. 

The first step in the reaction is adsorption of Pronto the catalyst surface. Complexation between catalyst and alkene then occurs as a vacant orbital on the metal interacts with the filled alkene tt orbital. In the final steps, hydrogen is inserted into the double bond and the saturated product diffuses away from the catalyst (Figure 7.7). The stereochemistry of hydrogenation is syn because both hydrogens add to the double bond from the same catalyst surface. 

E.A. Brocchi, P.K. Jena, F.J. Moura, O. Barbosa-Filho, R.J. de Carvalho, Chloride metallurgy 2002 Practice and theory of chlorine/metal interaction, Annual Hydrometallurgy Meeting, Oct. 19-23,2002,1 (2002) 229. 

The metal-metal interaction and conductivity increase with pressure using bulkier ammines increases the Pt-Pt distance. Although palladium-containing ions can be substituted for the platinum species, the optical properties and metal-metal interaction causing pronounced dichroism are... 

Structure and metal-metal interactions in copper(II) carboxylate complexes. R. J. Doedens, Prog. Inorg. Chem., 1976, 21, 209-231 (70). 

Metal-metal interactions in transition metal complexes containing infinite chains of metal atoms. T. W. Thomas and A. E. Underhill, Chem. Soc. Rev., 1972,1, 99-120 (70). 

Carbonyldlimidazolc, 78 Carbonyl-metal interactions, 74 Carbosiloxadienes, 452 Carboxy-ester interchange melt polyesterification, 113 Carboxy-ester interchange reactions, 62, 64, 69, 74... 

On the whole, theoretical calculations provide only a general insight into the problem of water-metal interactions, probably because not all factors are appropriately taken into account. Thus the agreement of AX data with A

theoretical calculations. Nevertheless, each author claims good agreement with some experimental facts, with the outcome that plenty of hydrophilicity scales have been suggested23,153,352 389 399 834 870 890,892 893 based on different parameters these have increased the entropy of the situation with a loss of clarity. 

Indirect ( through the metal ) interaction due to the redistribution of electrons in the metal. In this case an electropositive promoter decreases the work function of the surface and this in turn weakens the chemisorptive bond of electropositive (electron donor) adsorbates and strengthens the chemisorptive bond of electronegative (electron acceptor) adsorbates. 

R.A. DePaola, J. Hrbek, and F.M. Hoffmann, Potassium promoted C-0 bond weakening on Ru(001). I. Through-metal interaction at low potassium precoverage, J. Chem. Phys. 82(5), 2484-2498 (1985). 

The B atoms in the mono- and diaminoboranes (R2N)2BR and R2NBR2 show only moderate functions. Therefore, boron-metal interactions are relatively weak. 

Strong boron-transition metal interaction interatomic distances are shorter by 5-10%, as compared to the sum of the metal radii. 

Cohen lA (1980) Metal-Metal Interactions in the Metalloporphyrins, Metalloproteins and Metalloenzymes. 40 1-37... 

Licoccia S, Paolesse R (1995) Metal Complexes of Corroles and other Corrinoids. 84 71-134 Lin Z, Fan M-F (1997) Metal-Metal Interactions in Transition Metal Clusters with n-Donor Ligands. 87 35-80... 

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