A mechanistic insight into metal-cluster pi-envelopment: a dual binding mode involving bent and planar ligand-conformers

作者：Masai Kohei; Shirato Katsunori; Yamamoto Koji; Kurashige Yuki; Murahashi Tetsuro^*

来源：Chemical Communications, 2016, 52(38): 6427-6430.

DOI：10.1039/c6cc01536k

Metal clusters are effectively stabilized by bridging pi-coordination of planar pi-conjugated unsaturated hydrocarbons. However, the mechanism of pi-envelopment of a metal cluster has been elusive. By employing 1,2-bis(4-aryl-1,3-butadienyl)benzene as the pi-conjugated ligand, we found that the pi-envelopment of a Pd-4 cluster proceeded in a stepwise manner, where the sp(2)-carbon ligands initially envelop the Pd-4 cluster through a bent binding mode, and then isomerized to a thermodynamically more stable planar mode under mild heating or visible light irradiation. The involvement of a bent binding mode indicates the kinetically preferred coordination at the axial coordination site trans to a metal-metal bond.

• 出版日期2016