Synthesis and structure of a molecular metal wheel,an octanuclear silver(I) cluster formed by racemic 2-mercaptopropionic acid and triphenylphosphine ligands

摘要

The molecular structure of [H_4Ag_8(2-mpa)_6(PPh_3)_6·EtOH 1 (2-H_2mpa=a racemicform of 2-mercaptopropionic acid),prepared by a 1:5 molar-ratio reaction of polymeric [Ag(2-Hmpa)]_n2 suspendedin EtOH with PPh_3 in CHCl_3,was a wheel-type octanuclear silver9I) cluster;the rim of the wheel was constructed with the outside six Ag(mu_3-S)_2 P units and the axle wasformed by the central two Ag(mu_3-S)_3 units with Ag-Ag separation,3.122A.