Luminescence color switching of supramolecular assemblies of discrete molecular decanuclear gold(I) sulfido complexes

Abstract

A series of discrete decanuclear gold(I) μ 3 -sulfido complexes with alkyl chains of various lengths on the aminodiphosphine ligands, [Au 10 {Ph 2 PN(C n H 2n+1 )PPh 2 } 4 (μ 3 -S) 4 ](ClO 4 ) 2 , has been synthesized and characterized. These complexes have been shown to form supramolecular nanoaggregate assemblies upon solvent modulation. The photoluminescence (PL) colors of the nanoaggregates can be switched from green to yellow to red by varying the solvent systems from which they are formed. The PL color variation was investigated and correlated with the nanostructured morphological transformation from the spherical shape to the cube as observed by transmission electron microscopy and scanning electron microscopy. Such variations in PL colors have not been observed in their analogous complexes with short alkyl chains, suggesting that the long alkyl chains would play a key role in governing the supramolecular nanoaggregate assembly and the emission properties of the decanuclear gold(I) sulfido complexes. The long hydrophobic alkyl chains are believed to induce the formation of supramolecular nanoaggregate assemblies with different morphologies and packing densities under different solvent systems, leading to a change in the extent of Au(I)-Au(I) interactions, rigidity, and emission properties.luminescence | color switching | nanoaggregate | gold cluster G old(I) complexes are one of the fascinating classes of complexes that reveal photophysical properties that are highly sensitive to the nuclearity of the metal centers and the metalmetal distances (1-59). In a certain sense, they bear an analogy or resemblance to the interesting classes of metal nanoparticles (NPs) (60-69) and quantum dots (QDs) (70)(71)(72)(73)(74)(75)(76) in that the properties of the nanostructured materials also show a strong dependence on their sizes and shapes. Interestingly, while the optical and spectroscopic properties of metal NPs and QDs show a strong dependence on the interparticle distances, those of polynuclear gold(I) complexes are known to mainly depend on the nuclearity and the internuclear separations of gold(I) centers within the individual molecular complexes or clusters, with influence of the intermolecular interactions between discrete polynuclear molecular complexes relatively less explored (34-38), and those of polynuclear gold(I) clusters not reported. Moreover, while studies on polynuclear gold(I) complexes or clusters are known (34-54), less is explored of their hierarchical assembly and nanostructures as well as the influence of intercluster aggregation on the optical properties (34-38). Among the gold(I) complexes, polynuclear gold(I) chalcogenido complexes represent an important and interesting class (44-51). While directed supramolecular assembly of discrete Au 12 (52), Au 16 (53), Au 18 (51), and Au 36 (54) metallomacrocycles as well as trinuclear gold (I) columnar stacks (34-38) have been reported, there have been no corresponding studies on the supramolecular hierarchical assembly of polynuclear gold(I) chalc...

Synthesis, structural characterization, and photophysical studies of hexanuclear gold(I) chalcogenido complexes

“…The synthesis of the gold(I) sulfido complex was achieved by reacting the chlorogold(I) phosphine precursor with freshly produced H 2 S [5b,g,7]. The gold(I) selenido complex was similarly synthesized using freshly prepared Li 2 Se in place of H 2 S [5g].…”

“…As a result of the highly versatile bonding modes of the chalcogenido ligands and extensive intramolecular aurophilic interactions that support the self‐assembled structures, a number of polynuclear gold(I) chalcogenido clusters with bridging phosphine ligands were reported . With functionalization of the bridging phosphines, desired properties could be incorporated into the polynuclear gold(I) scaffolds, producing clusters with self‐assembly, cluster‐to‐cluster transformation, photoinduced isomerization, or heterochiral self‐sorting properties. Reports on polynuclear gold(I) selenido complexes were relatively scarce when compared to their sulfido counterparts, with the choices of bridging ligands mainly limited to phosphines with aliphatic pendants [5g,11–13] .…”

Syntheses, structures and theoretical investigations of [Au10S2(PPh2)2(dppma2)4(dppma3)]·[Au6S2(dppma2)2(dppma3)]

“…4(3) to 228.4(3) pm, respectively, and the Au-S-Au angles are between 86.8(1)°a nd 107.2(1)°; deviations from the ideal value of 90°are often observed in gold(I) μ 3 -sulfido complexes. [5][6][7][8]14 As shown in Fig. 1, 1a and 1b interdigitate, reminding of a lock-and-key like arrangement of both subunits.…”

“…E = S, Se; X = H, Me, OMe, F, Cl, Br). 7,8 In this work, we report on further extension of the investigations considering ligands that are based on maleic anhydride. In particular, we used a chlorogold(I) precursor containing the 2,3-bis(diphenylphosphino)maleic anhydride (dppma) ligand, [(AuCl) 2 (dppma)], to form polynuclear gold(I) µ 3 -sulfido clusters.…”

Silver(I)‐Based Complexes Used as High‐Performance Photocatalysts for the Degradation of Organic Dyes in Water

“…Sulfur atom displays good affinity for Au,, Ag and Cu, resulting in the formation of many polynuclear metal complexes with unique fluorescence and photocatalysis properties . How to combine P and S donor atoms together into polynuclear metal complexes has received much interest , .…”