Allenylidene and Higher Cumulenylidene Complexes

Carbon-atom wires: 1-D systems with tunable properties

“…88 Short cumulenes can be synthesized in a similar way by controlling the termination-induced electronic arrangement. Such a strategy has been discussed in the review by Cadierno et al, 118 and the synthesis of cumulene wires has been reported by Cataldo 119 and more recently by Tykwinski and coworkers 82,83 which describes cumulene wires up to 8 sp-carbon atoms produced by means of stepwise chemical synthesis. In all of these systems, the choice of terminal groups for the cumulene is fundamental for multiple reasons.…”

Alkyne activation by half-sandwich ruthenium(II) complexes bearing the water-soluble phosphane 1,3,5-triaza-7-phosphaadamantane (PTA)

“…In the same way, allenylidene complexes can also react with electrophiles to yield vinylcarbine complexes [22][23][24][25]. These reactions could compete with the electrophilic attack to one of the nitrogen atoms of the PTA phosphane ligand.…”

Polynuclear carbon-rich organometallic complexes: clarification of the role of the bridging ligand in the redox properties

“…Finally, fewer studies have been carried out with cumulenic compounds of the type [M]( C) n R 2 which are relatively easy to reduce. 45 Addition of an extra electron was experimentally demonstrated to occur on the odd numbered carbon atoms of the chain in ruthenium complexes (n = 3 and 5), on the basis of EPR, IR and spin trapping experiments. 46 One example is displayed in Scheme 4 with the metal allenylidene 6, for which a resolved EPR signal is observed at room temperature with g = 2.0042, characteristic of an organic radical.…”