No abstract

Despite the abundance of "sandwich" complexes, in which two cyclic aromatic hydrocarbon ligands flank a metal center, this motif has not been extended to sheets of multiple metal atoms. We prepared and isolated two such compounds. In the first, three palladium centers form a planar triangular array, capped by chlorides, between two cycloheptatrienyl ligands. In the second, a pentapalladium sheet adopts an edge-sharing triangle-trapezoid skeleton between two naphthacene rings. The compounds were characterized by x-ray crystallography and nuclear magnetic resonance spectroscopy. The nature of bonding in the clusters was analyzed by quantum calculations.

The first homoleptic nitrile dipalladium(I) complex [Pd 2 (CH 3 CN) 6 ][BF 4 ] 2 is prepared; the CH 3 CN ligand undergoes facile displacement by phosphine or bidentate nitrogen ligands while the Pd-Pd bond remains intact.

No abstract

An unusual square tetrapalladium sheet sandwich complex, [Pd(4)(mu(4)-C(9)H(9))(mu(4)-C(8)H(8))][B(Ar(f))(4)] has been isolated and structurally characterized. X-ray structure analysis showed that the square palladium sheet is flanked by the nine-membered cyclononatetraenyl and eight-membered cyclooctatetraene ligands to form a square metal sheet molecular sandwich structure. The coordinative unsaturation of the complex was revealed by phosphine titration experiments.

No abstract

Carotenes are naturally abundant unsaturated hydrocarbon pigments, and their fascinating physical and chemical properties have been studied intensively not only for better understanding of the roles in biological processes but also for the use in artificial chemical systems. However, their metal-binding ability has been virtually unexplored. Here we report that β-carotene has the ability to assemble and align ten metal atoms to afford decanuclear homo- and heterometal chain complexes. The metallo–carotenoid framework shows reversible metalation–demetalation reactivity with multiple metals, which allows us to control the size of metal chains as well as the heterobimetallic composition and arrangement of the carotene-supported metal chains.

Bis-perylene-tetrapalladium sandwich complexes are synthesized and structurally characterized. These are the first examples of bis-arene sandwich complexes having metal-metal bond chains. X-ray crystallographic analyses showed that the tetrapalladium chain is bound to perylene ligands at the C8 edge position.