Control the Single‐, Two‐, and Three‐Photon Excited Fluorescence of Atomically Precise Metal Nanoclusters

Abstract

It remains challenging to control the single-, two-, and three-photon excited fluorescence of metal nanoclusters. In this work, the control over the nonlinear optics of metal nanoclusters as single-, two-, and three-photon excited fluorescence has been accomplished via exploiting the solvent effect. An emissive nanocluster, Au 9 Ag 6 (SPh t OMe) 4 (DPPOE) 3 Cl 3 , was synthesized and structurally determined. The solvent effect can not only control the fluorescence of this nanocluster, but more significantly, it can also regulate the photoluminescence nature of the cluster as single-, two-, and three-photon excited fluorescence. We concluded that the increased solution polarity, improved dipole moment, enlarged HOMO-LUMO energy gap, and reduced solution viscosity of the cluster in solutions endow them with excellent high-order multiphoton excited fluorescence. The results provide an intriguing cluster template that enables us to manipulate the linear and nonlinear optics at the atomic level.

Probing the surface-active sites of metal nanoclusters with atomic precision: a case study of Au5Ag11

“…Such a difference might be attributed to the typical solvent-dependent single-photon excited fluorescence and their different crystalline packing modes. 62 Indeed, the different space groups of Pca 2 1 , I 2/ a , and Ccca for Au 5 Ag 11 -DMBT , Au 5 Ag 9 Cu 2 -DMBT , and Au 5 Ag 11 -DCBT , respectively, might also result in distinct optical behavior of these cluster crystals (Fig. S10–S12†).…”

A supramolecular assembly strategy towards organic luminescent materials

“…Compared with conventional fluorescence, multi-photon excited fluorescence (MPEF) has the advantages of stronger spatial confinement, longer penetration depth, less biological damage and less Rayleigh scattering. In 2022, Zhu, Kang and Zhang et al 39 proposed that the solvent effects could regulate single-, two-, and three-photon excited fluorescence of nanoclusters (Fig. 6c).…”

Lone-pair, electron-dominated, nonlinear optical responses in sulfur clusters and electric tunability properties

“…14 Recent advancements in cluster science have provided promising opportunities to address this dilemma. 15–18 Compared with traditional inorganic crystals, clusters have tunable geometries and electronic structures, thus making them a promising source of novel nonlinear optical materials.…”