Oligocyclopentadienyl Transition Metal Complexes

Abstract

Synthesis, characterization, and reactivity studies of oligocyclopentadienyl transition metal complexes, namely those of fulvalene, tercyclopentadienyl, quatercyclopentadienyl, and pentacyclopentadienyl(cyclopentadienyl) are the subject of this account. Thermal-, photo-, and redox chemistries of homo-and heteropolynuclear complexes are described.

New Rh derivatives of s-indacene active in dehydrogenative silylation of styrene

“…Indeed, cyclopentadienyl ligand is ubiquitous in organometallic chemistry since it can bind to a large number of metals with different oxidation states. However, in contrast to the well-documented chemistry of fulvalene and fulvalene-like bridged binuclear complexes [4,7], chemical reactivity of dimetallic fused rings systems has been much less developed. These rare investigations were focused on ligand mobility and substitutional lability, steps which are fundamental for the development of potential catalyst.…”

Synthesis and cyclic voltammetry of some new metal carbene substituted cyclopentadienyliron half sandwich complexes

“…Such interactions might result in new properties deriving from either participating metal and might therefore be different from a formal sum of the distinct properties caused by the single metal. In many cases, metals of oligonuclear complexes are connected by p ligands such as fulvalenes [7,14,[16][17][18][19], biphenyl [7,[20][21][22][23][24][25], stilbene [26], oligophenylenes [27], etc. Alternatively there are complexes, in which the metals are directly incorporated in the connecting p system, for example in bimetallic cumulenylidene or oligoalkynediyl complexes [28][29][30][31][32][33][34][35].…”

The Fulvalenes

“…Our own reviews on cycloproparene chemistry have included the (alkylidene)cycloproparenes that also are regarded as benz-annulated fulvalenes. [8] More recent compilations encompassing fulvalenes have provided for specific sub-classification with works on azafulvalenes, [9] azathiafulvalenes, [10] fulvalene ylides, [11] organometallic derivatives [12] and (especially) on the use of tetrathiafulvalenes in material science endeavours, [13] with the publication of a thematic issue of Chemical Reviews on Molecular Conductors. [14] These are not discussed further here.…”