An Atomically Precise Au₁₀Ag₂ Nanocluster with Red–Near‐IR Dual Emission

Abstract

A red-near-IR dual-emissive nanocluster with the composition [Au10 Ag2 (2-py-C≡C)3 (dppy)6 ](BF4 )5 (1; 2-py-C≡C is 2-pyridylethynyl, dppy=2-pyridyldiphenylphosphine) has been synthesized. Single-crystal X-ray structural analysis reveals that 1 has a trigonal bipyramidal Au10 Ag2 core that contains a planar Au4 (2-py-C≡C)3 unit sandwiched by two Au3 Ag(dppy)3 motifs. Cluster 1 shows intense red-NIR dual emission in solution. The visible emission originates from metal-to-ligand charge transfer (MLCT) from silver atoms to phosphine ligands in the Au3 Ag(dppy)3 motifs, and the intense NIR emission is associated with the participation of 2-pyridylethynyl in the frontier orbitals of the cluster, which is confirmed by a time-dependent density functional theory (TD-DFT) calculation.

Isolation and Total Structure Determination of an All‐Alkynyl‐Protected Gold Nanocluster Au144

“…Recently,a lkynyl ligands were employed in the synthesis of gold nanoclusters. [50][51][52][53][54][55][56][57][58][59][60] Staple motifs PhC C À (Au À C CPh) n (n = 1o r2 )s imilar to but different from RS À (Au À SR) n were also observed. [61][62][63] It is notable that alkynyl analogues of thiolate-stabilized gold nanoclusters can be synthesized, [64] and crucial ligand effects in catalysis have also been reported.…”

Unravelling the origin of dual photoluminescence in Au2Cu6 clusters by triplet sensitization and photon upconversion

“…7 To realize these applications, it is important to profoundly understand the underlying photophysics of the clusters, including their photoabsorption and photoluminescence (PL) properties. As is well known, dual PL and multiple PL decay are frequently observed in ligand-protected gold, silver, and their alloy clusters at room temperature; [8][9][10][11][12] however, their origin remains unclear. The exact origin of the PL is difficult to identify because of the presence of multiple emission sites in the clusters, such as the metal core and surface staple, [7][8][9][10][11][12] as well as the contribution of electronic states with different spin multiplicities (i.e., excited singlet and triplet states) to these emission sites.…”

Vapochromic Gold(I)–Silver(I) Cluster Protected by Alkynyl and Phosphine Ligands

“…The formation of coinage metal clusters are facilitated by intense metallophilic interactions between d 10 metals, such as gold(I) and silver(I). Negative charged alkynyl is one of the most extensively studied ligands in these systems, as they may form both σ‐ and π‐binding to metal ions . In some cases, phosphine ligands are also introduced to act as peripheral protecting ligands and to enhance the stability of the structures.…”