By using a chiral tetraphosphine, rac-bis[(diphenylphosphinomethyl)phenylphosphino]methane (rac-dpmppm), linear octapalladium chains were synthesized as discrete molecules of [Pd (μ-rac-dpmppm) L ](BF ) (L=CH CN, dmf, XylNC), [Pd (μ-rac-dpmppm) ](BF ) , and [Pd (μ-rac-dpmppm) (Cl) ](BF ) , which are stable in the solution states and characterized by spectroscopic and crystallographic methods to reveal the octapalladium chains supported by homochiral four tetraphosphines. Variable-temperature NMR studies for a 1:1 mixture of [Pd (μ-rac-dpmppm) (dmf) ](BF ) and [Pd (μ-meso-dpmppm) (dmf) ]-(BF ) in [D ]DMF revealed that the Pd chains were dissociated at higher temperature (T≈140 °C) into the Pd units of {Pd (μ-rac-dpmppm) } and {Pd (μ-meso-dpmppm) } , and they were thermodynamically self-aligned to restore the Pd chains at lower temperature (T<60 °C), through perfect chiral self-recognition between the stereogenic tetrapalladium units.

A new linear hexaphosphine, rac-cis,cis,trans-bis{[(diphenylphosphinomethyl)phenylphosphinomethyl]phenylphosphino}methane (P6), was synthesized and isolated as a pure isomer, confirmed by transforming to the corresponding phosphine sulfide. The methylene-bridged linear hexaphosphine readily organized flexible gold(I) and silver(I) hexanuclear chains, [M6(μ-P6)2]X6 (X6 = (OTf)6, M = Au (1), Ag (2); X6 = Cl2(PF6)4, M = Au (3)). The hexaphosphine also supported a tetrasilver(I) complex [Ag4(μ-P6)2](OTf)4 (4), which was readily transformed by treatment with AgOTf into 3, revealing a drastic alternation of the two P6 arrangement. The hexagold(I) chains exhibited a considerably red-shifted absorption (∼410 nm) and emission (540-580 nm) to (1) [5dσ*→6pσ] and from (3) [5dσ*→6pσ] excited states of the metal centers, respectively. The new linear hexaphosphine could be a useful tool to construct linear metal clusters as subnano building blocks.

Chiral self‐recognition between stereogenic tetrapalladium units, [Pd4(rac‐dpmppm)2]2+ ((RR)2, (SS)2) and [Pd4(meso‐dpmppm)2]2+ ((RS)2) {dpmppm=[(Ph2PCH2)PhP]2CH2}, afforded Pd8 chains supported by homochiral dpmppm ligands, [Pd8(rac‐dpmppm)4]4+ ((RR)4, (SS)4) and [Pd8(meso‐dpmppm)4]4+ ((RS)2(SR)2, (SR)2(RS)2). Among ten possible stereoisomers, only four Pd8 chains were thermodynamically self‐aligned; the C2 chiral structure of the chain is determined by the configuration of the P centers inside. More information can be found in the Communication by T. Tanase et al. on page 524 ff.