Search

Carbon suboxide, C3, O2, reacts with a great variety of organometallic compounds. With organo-silicon and aluminium compounds it reacts with the C˭O moiety, giving sililation and carboalumination reactions. Insertion reactions of C˭C are performed with compounds having M-H, M-OR, M-NR2, M-PR2 bonds (M ≠ Si, Al), giving mono-metal derivatives (ketenyl) or di-metal derivatives of acil groups (amides, esthers, phospides). The coordination of C˭O or C˭C to transition metal complexes, the formation of allenic compounds and the decarbonylation reactions allow the synthesis of a series of particular metal derivatives (ketenyl, ketenylidene and carbonyl complexes) which, in some cases, present a peculiar reactivity.

The coordination and organometallic chemistry of P- and As-carbonyl stabilized ylides is reviewed. As a general feature, the coordination chemistry of R3ECHCOR′-type (E=P, As) ligands appears to be dominated by C(ylide) metal coordination, although a few examples of O(ylide)-bound complexes are known. The factors addressing C(ylide)-vs. O(ylide)-coordination in Pt(II) and Pd(II) systems are examined. The Ni(II) complexes containing P,O-chelate ylide ligands are also discussed, with a special emphasis on their catalytic activity. The synthesis and reactivity of phosphonium functionalized isocyanides and their corresponding ylides, which provide a new route to metal coordinated indole systems, are described. Finally, the reactivity of Ph3PCCO towards metal substrates is summarized including the formation of ketenyl complexes.

The preparation, characterization, and optimization of the functional properties of mono- and polynuclear coordination complexes containing heteroaromatic nitrogen ligands are discussed here, taking the advantage of numerous studies performed in our laboratories on exploring a variety of different metal ions and polytopic ligands. We highlight how very minor changes in connectivity, composition, and polarity of the molecular entities employed in the self-assembly steps may significantly affect the structural, thermal, sorptive, magnetic, and mesomorphic behavior of the resulting materials. Examples from three different classes are included: 1) pyrazolate-based polynuclear coordination compounds, 2) homoleptic and heteroleptic coordination polymers, and 3) 2,2'-bipyridine metal-based liquid crystals.