Polymorphism of Ag₂₉(BDT)₁₂(TPP)₄³⁻ cluster: interactions of secondary ligands and their effect on solid state luminescence

Abstract

We present the first example of polymorphism (cubic & trigonal) in single crystals of an atomically precise monolayer protected cluster, Ag29(BDT)12(TPP)43-. We demonstrate that C-Hπ interactions of the secondary ligands (TPP) are dominant in a cubic lattice compared to a trigonal lattice, resulting in a greater rigidity of the structure, which in turn, results in a higher luminescence efficiency in it.

Rendering hydrophobic nanoclusters water-soluble and biocompatible

“…It has been demonstrated that the crystal of Ag 29 -Na 0 emitted at 670 or 700 nm with different crystalline patterns. 53 However, the emissions of Ag 29 -Na 1 and Ag 29 -Na 3 luminesced at 637 and 694 nm, respectively ( Fig. 2E; and see Fig.…”

“…Although all types of Ag 29 nanoclusters (Ag 29 -Na 0 , Ag 29 -Na 1 , and Ag 29 -Na 3 ) presented cubic-like crystals at the macro-level (Fig. 2C,D, insets), 52,53 the emissions of them were entirely different. It has been demonstrated that the crystal of Ag 29 -Na 0 emitted at 670 or 700 nm with different crystalline patterns.…”

“…It should be noted that no Na + cation (or other cations) has been observed in the crystal lattice of Ag 29 -Na 0 in both crystals of Ag 29 (SSR) 12 (PPh 3 ) 4 reported by the Bakr and the Pradeep groups, which might result from the high disorder of these Na + counterions. 52,53 Indeed, induced by the xation of the crown ether, Chakraborty et al captured these Na + cations in a form of Na + @dibenzo-18-crown-6. 59 In this work, for both Ag 29 -Na 1 and Ag 29 -Na 3 nanoclusters, the Na + counterions were xed by oxygen-carrying solvents such as NMP and DMF to generate the solvent-conjoined cations.…”

“…PPh 3 )4 ] 3À was based on the reported method of the Bakr and the Pradeep groups 52,53. COONa was added under vigorous stirring at 273 K (ice-bath).…”

Polymorphism of Au11(PR3)7Cl3 clusters: understanding C–H⋯π interaction and C–H⋯Cl–C van der Waals interaction on cluster assembly by surface modification

“…[11][12][13] Ligands play a crucial role in the stabilization of nanoclusters. [14][15][16][17] The non-covalent interactions between surface ligands not only alter properties of clusters but also have signicant effects on nanocluster assembly and selfassembly. [18][19][20][21][22][23][24][25][26][27][28][29][30] For instance, Wu and co-workers demonstrated that C-H/p interactions facilitated the chiral arrangement of ligands, and the assembled ligands presented rotational and parallel patterns on the surface of the nanoparticles.…”