Organometallics and Metal-Ligand Complexes

Complexes between organometallic or metal hydride complexes and hard bases have attracted attention recently.1 In many cases the reaction solvent plays the role of a Lev is base such complexes can be catalytically active by solvent ligand dissociation.2,3 We describe here the complexes [IrH2S2(PPh3)2][BF4], where S = Me2CO,4,5 H20,5 or S2 = o-... 

Keeping our target of homogeneous catalysis in mind, we adopted a broad definition of organometallic complexes and included compounds without metal-carbon bonds (e. g., metal-phosphine and metal-nitrosyl complexes) as far as they retain the structural and reactivity features of typical organometallic compounds. Recent developments, e. g., the substitution of phosphine by carbene ligands (cf Section 3.1.1.1), support the validity of this view. 

The application of organometallic compounds in medicine, pharmacy, agriculture and industry requires the accurate determination of these metals as part of their application. Most % complexes characterised by direct carbon-to-carbon metal bonding may be classified as organometallic and the nature and characteristics of the n ligands are similar to those in the coordination metal-ligand complexes. The -complex metals are the least satisfactorily described by crystal field theory (CFT) or valence bond theory (VBT). They are better treated by molecular orbital theory (MOT) and ligand field theory (LFT). There are several uses of metal 7i-complexes and metal catalysed reactions that proceed via substrate metal rc-complex intermediate. Examples of these are the polymerisation of ethylene and the hydration of olefins to form aldehydes as in the Wacker process of air oxidation of ethylene to produce acetaldehyde. 

In this chapter we present an overview of d , d , and d metal-based organometallic compounds suitable for cellular imaging. In particular, liuninescent complexes containing Re(I), Ir(III), Rh(III), Pt(II), and Au(I) and metal carbonyl complexes of Re, Os, and Mn will be discussed. Depending on the metal and the ligands present, each complex may be suitable for visualizing biological systems via different detection methods. 

The participation of siloxane groups in the reaction increases with the temperature of dehydration of Si02 and quantity of organometallic compound introduced in the reaction. According to the data of infrared spectroscopy (139), the allyl ligands formed in the surface organometallic complexes of Ni and Cr keep the 7r-allyl character of the metal-ligand bond. 

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