Chiral Octapalladium Chains Supported by Enantiopure -Stereogenic Linear Tetraphosphines, ()- and ()-PhPCHP(Ph)CHP(Ph)CHPPh.

Binuclear Pd(II) and Pt(II) complexes supported by -dpmppm (bis[(diphenylphosphinomethyl)phenylphosphino]methane) in a triply-bridged -form, [MCl(-dpmppm)] (M = Pd (), Pt ()), readily reacted with 2,6-xylyl isocyanide (XylNC) in the presence of NHPF to afford [MCl(-dpmppm)(XylNC)](PF) (M = Pd (), Pt ()), in which each metal center accommodates one isocyanide ligand at the position to the inner P atom of dpmppm. Similarly, treatment of and with axially chiral ()-1,1'-binaphthyl-2,2'-bisisocyanide (-Binac) in the presence of NHOTf gave cyclic tetranuclear complexes, [{MCl(-dpmppm)(-Binac)}](OTf) (M = Pd (), Pt ()), where two {MCl(-dpmppm)} fragments are connected by two -Binac ligands through chirality sorting of ()-dpmppm and ()-Binac. Complex could be transformed into the halide exchanged tetranuclear complexes, [{PdX(-dpmppm)(-Binac)}](OTf) (X = Br (), I ()), to show that the rectangular arrangement of four Pd(II) ions is elongated by repulsive interaction between halide ligands.

Chiral Self-Recognition between Stereogenic Tetrapalladium Units Affording Pd Chains Supported by Homochiral Tetraphosphines.

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.

Strongly luminous tetranuclear gold(I) complexes supported by tetraphosphine ligands, meso- or rac-bis[(diphenylphosphinomethyl)phenylphosphino]methane.

A series of tetragold(I) complexes supported by tetraphosphine ligands, meso- and rac-bis[(diphenylphosphinomethyl)phenylphosphino]methane (meso- and rac-dpmppm) were synthesized and characterized to show that the tetranuclear Au(I) alignment varies depending on syn- and anti-arrangements of the two dpmppm ligands with respect to the metal chain. The structures of syn-[Au4 (meso-dpmppm)2X]X'3 (X = Cl; X' = Cl (4 a), PF6 (4 b), BF4 (4 c)) and syn-[Au4 (meso-dpmppm)2]X4 (X = PF6 (4 d), BF4 (4 e), TfO (4 f); TfO = triflate) involved a bent tetragold(I) core with a counter anion X incorporated into the bent pocket. Complexes anti-[Au4 (meso-dpmppm)2]X4 (X = PF6 (5 d), BF4 (5 e), TfO (5 f)) contain a linearly ordered Au4 string and complexes syn-[Au4 (rac-dpmppm)2X2]X'2 (X = Cl, X' = Cl (6 a), PF6 (6 b), BF4 (6 c)) and syn-[Au4 (rac-dpmppm)2]X4 (X = PF6 (6 d), BF4 (6 e), TfO (6 f)) consist of a zigzag tetragold(I) chain supported by the two syn-arranged rac-dpmppm ligands.