Chemistry Departmental Seminar – Dr. Zhong-Ming Sun

About the event

Professor Zhong-Ming Sun, from Nankai University, research focuses on main-group metal clusters and fundamental chemical bonding.: Prof. Zhong-Ming Sun, Nankai University

Hosts: Prof. Ivan Popov and Prof. Jack Zhang

Title: New sandwich compounds with group 15 cyclo rings as ligands

Abstract: Since the discovery of ferrocene in 1951, sandwich compounds have shaped modern organometallic chemistry. We have developed an efficient method to synthesize novel sandwich complexes by combining Zintl solid-phase and organometallic compounds in an organic solvents medium. Through redox reactions at ambient temperature between an Fe(III) complex and the cyclo-P4²⁻ ligand, we synthesized the [Fe(η⁴-P4)₂]²⁻ anion. Building on this, we controlled the preparation of aromatic cyclo-As5⁻ ligands to obtain another sandwich complex featuring a Co12 cluster with Ih symmetry.

Extending this approach to heavier group 15 elements, Sb and Bi, we synthesized the triple-decker sandwich anions [(VCp)₂Sb5]²⁻ and [(NbCp)₂Bi5]²⁻, marking the first solid-phase isolation of a Bi5 pentagonal ring. Unlike previous high-temperature syntheses, both complexes form under mild, room-temperature conditions. DFT calculations reveal the cyclo-Sb5/Bi5 rings demonstrating alternating aromatic and anti-aromatic character in these clusters.