A stable zerovalent palladium chain enveloped by a π-electron sheath of conjugated polyene ligands

Abstract

A surprisingly stable homoleptic Pd(0)(4) chain complex of non-activated olefins was isolated and structurally characterized by X-ray crystallographic analysis, and the unique structure and bonding are compared to those of the corresponding dicationic [Pd(4)](2+) chain sandwich complex.

Chiral Self‐Recognition between Stereogenic Tetrapalladium Units Affording Pd8 Chains Supported by Homochiral Tetraphosphines

“…One-dimensionale xtended single-metal-atom chains, so-called EMACs, are one of the most theoretically important and fundamental single molecules to study quantum electron transporting phenomena and to develop molecularly based electronic devices.A lthoughi nt he last two decades, many research groups have tried to synthesize such molecules,t he successful studies have still been quite limited to those utilizing linearly designed template ligands. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] Peng and co-workersh ave established the Ni 9 and Ni 11 chains supported by polypyridyl-and polynaphthyridylamide ligands, respectively,a st he longest structurally characterizede xamples. [8,9] Murahashi et al have developed Pd chains by using conjugatedp olyene ligands, [10][11][12][13][14] and recently synthesized Pd 10 chains sandwiched by two b-carotenes.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14] Peng and co-workersh ave established the Ni 9 and Ni 11 chains supported by polypyridyl-and polynaphthyridylamide ligands, respectively,a st he longest structurally characterizede xamples. [8,9] Murahashi et al have developed Pd chains by using conjugatedp olyene ligands, [10][11][12][13][14] and recently synthesized Pd 10 chains sandwiched by two b-carotenes. [14] These compounds are promising candidates of buildingb locks for extending the metala tom chains, but the length of the EMACse ntirely depends on the length of the organic ligands.…”

Self‐Alignment of Low‐Valent Octanuclear Palladium Atoms

“…[2] Along this line, the ultimately thinnest electric wire that may consist of a single-metal-atom chain sheathed with insulating materials, so-called "extended metal atom chains" (EMACs), is one of the most theoretically important and challenging targets, because the anisotropically confined electrons in a single metallic chain would be predicted to exhibit fundamentally different transport properties, conceptually corresponding to the transition from atomic to bulk electronic behavior.Although their reproducible synthesis is extremely difficult at present, one of the promising strategies involves a procedure of molecular chemistry that constructs linearly ordered multinuclear metal complexes as discrete molecular EMACs. Several groups have synthesized molecular EMACs by using linearly well-designed multidonor organic ligands as guiding templates, [3][4][5][6][7][8][9][10][11][12][13][14] establishing Ni 9 and Ni 11 chains supported by polypyridyl-and polynaphthyridylamide ligands, respectively, as the longest end of structurally characterized examples. [9,10] These compounds are promising building blocks for extending the metal atom chains, whereas the length of the molecular EMACs is still quite limited and entirely depends on the length of the organic ligands.…”

Low Valent Palladium Clusters: Synthesis, Structures and Catalytic Applications

“…And reverse reaction took place under the oxidation of [Cp 2 Fe][BAr f ]. [ 69 ] These unique transformations are due to flexible charge accommodation and coordination modes of ligands.…”