Group VIII ligands

The optical spectra of Ni, Pd and Pt in noble gas matrices have been measured in order to search for complexes of these Group VIII ligands. Changes in the energy levels of the matrix isolated atoms occur because of a weak metal interaction. For platinum the frequency shifts follow the trend Xe > Ar > Kr, but whether this interaction is described as a Van der Waals interaction or a weak coordinate bond is open to speculation.1976... 

The dioxygen ligand in mononuclear group VIII transition metal complexes. J. S. Valentine, Chem. Rev., 1973, 73, 235-245 (101). 

Alkenes. Most Group VIII metals, metal salts, and complexes may be used as catalyst in hydrosilylation of alkenes. Platinum and its derivatives show the highest activity. Rhodium, nickel, and palladium complexes, although less active, may exhibit unique selectivities. The addition is exothermic and it is usually performed without a solvent. Transition-metal complexes with chiral ligands may be employed in asymmetric hydrosilylation 406,422... 

Sulfurdiimine, Azabutadiene and Triatomic Hetero Anion Ligands (vi) Metals in Group VIII Ni, Pd, Pt... 

The cyanate complexes of the Group VIII metals are less common. A terminal N-bonded ligand is present in Ni(NCO)2(phen)2263a and a l,3-/i-bonded NCO in dimeric [BPh4][Ni2(tren)2(NCO)2] (cf. 100).230... 

All Group VIII, IX and X transition metals show some catalytic activity for hydroformylation, although cobalt and rhodium are the most active, rhodium catalysts being 104 times more reactive. More recently, platinum catalysts containing the trichlorostannate ligand have been shown to be selective catalysts that effect hydroformylation under mild conditions.6... 

Hybrid Multidentate Ligands Amido-Phos-phine Derivatives of Group VIII Metals... 

Tulchinsky ML, Abatjoglou AG (2009) Sulfonated trialkylphosphines as ligands for two-phase group VIII metal-catalyzed hydroformylation of long-chain olefinic substrates. WO 2009/091670... 

It is apparent from the examples in this section that the lability of the groups on silicon is greatly dependent on the catalyst. With conventional acid or base catalysts, SiO— is classed as a labile ligand, SiH as semi-labile, and Si—R (R = alkyl or aryl) as nonlabile (/). However, with low-valent complexes of the group VIII metals, SiH is the most labile ligand, and SiO— and Si—R appear to have comparable reactivities. Hence, these two sets of catalysts types are complementary in their capacity to redistribute ligands on silicon. 

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