Reviews ligand reactivity

Abstract The low-valent complexes of uranium (i.e. those containing U(III) centres) are characterised as reactive, highly reducing species that can effect novel, and potentially useful, transformations of small molecules. In this chapter we review one particular class of these compounds - those supported by cyciooctatetraene and pentaiene ligands -whose reduction chemistry has recently demonstrated novel and unexpected results, including the cyclooligomerisation of CO. The syntheses and structures of these compounds are presented, and their reactivity towards a variety of small molecules is examined and reviewed. The reactivity towards carbon monoxide is discussed in reference to the historical development of obtaining oxocarbons from CO. 

Before detailing the chemistry occurring between Ru(dppe)(C0)2[C(0)0Me]2 and amines, we will briefly review the reactivity of this unusual bis(methoxycarbonyl) complex. The two isomers, 3 and 3 interconvert by an intramolecular "ligand-hopping" mechanism in which a methoxy group migrates from a methoxycarbonyl to an adjacent metal carbonyl ligand.(18) The primary coordination sphere of this octahedral, dfi, Ru2+ complex is inert towards substitution on the timescale of all the... 

Ultimately this review should stimulate activity in areas where additional information must be obtained to allow a clearer understanding of the relationships between C NMR parameters, chemical bonding and coordinated ligand reactivities, and, furthermore suggest new applications of NMR in inorganic chemistry. 

This chapter reviews mechanistic studies on the stoichiometric reactions of coordinated hydrocarbons with nucleophiles and electrophiles, together with some related processes. Kinetic investigations of such reactions, especially nucleophilic additions, have increased considerably in recent years, greatly increasing our knowledge of the intimate mechanisms involved and of the factors important in controlling ligand reactivity. 

A review article entitled "Bulky amido ligands in rare-earth chemistry Syntheses, structures, and catalysis" has been published by Roesky. Benzamidinate ligands are briefly mentioned in this contexD The use of bulky benzamidinate ligands in organolanthanide chemistry was also briefly mentioned in a review article by Okuda et al. devoted to "Cationic alkyl complexes of the rare-earth metals S mthesis, structure, and reactivity." Particularly mentioned in this article are reactions of neutral bis(alkyl) lanthanide benzamidinates with [NMe2HPh][BPh4] which result in the formation of thermally robust ion pairs (Scheme 55). ... 

In this section, we start by describing the main features of the photolytic chemistry of iron pentacarbonyl and related species, focusing on the experimental data. We then describe our and other people s computational work aimed at understanding the reactivity of the fragments formed upon photolysis, with a focus on the spin-forbidden steps. We consider, in turn, the addition of ligands to Fe(CO)4, Fe(CO)3, and Fe(CO)3L (where L is a ligand such as H2 or ethene). For some of the reactions, we include some new computational results as well as a review of existing work. 

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