Tungsten–copper clusters assembled on porous alumina for optical limiting applications

Abstract

Cluster assembly materials with unique electronic and optical properties are significant for a variety of potential applications but often susceptible to intermolecular interactions which may alter the performance determined by their individual components. For the first time, here we report the assembly of a pyridine-protected tungsten–copper cluster on porous alumina, and find superior optical limiting (OL) properties retainable for multilevel clustering due to unaffected reverse saturable absorption (RSA) and constant photo-excited triplet states. Also clarified is that this transition metal W–Cu cluster bears an interesting framework structure with reasonable stability reinforced by strong donor–acceptor charge-transfer interactions.