Nanocluster superstructures or nanoparticles? The self-consuming scaffold decides. Issue 16 (11th April 2018)

• Record Type: Journal Article
• Authors: Suber, Lorenza; Imperatori, Patrizia; Pilloni, Luciano; Caschera, Daniela; Angelini, Nicola; Mezzi, Alessio; Kaciulis, Saulius; Iadecola, Antonella; Joseph, Boby; Campi, Gaetano
• Is Part Of: Nanoscale. Volume 10:Issue 16(2018)
• Page Start: 7472
• Page End: 7483
• Publication Date: 2018-04-11
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c7nr09520a
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : Formation of Ag thiolate nanocluster superstructure. Abstract : We show that using the same reaction procedure, by hindering or allowing the formation of a reaction intermediate, the Ag + dodecanethiolate polymeric complex, it is possible to selectively obtain Ag dodecanethiolate nanoparticles or Ag dodecanethiolate nanoclusters in the size range 4–2 nm. Moreover, the Ag dodecanethiolate nanoclusters display a lamellar superstructure templated from the precursor Ag + dodecanethiolate polymeric complex. A plausible formation mechanism is illustrated where, starting from the precursor and scaffold lamellar Ag + thiolate polymeric complex, first the nanocluster Ag n 0 core is formed by reduction of isoplanar Ag + ions, followed by Ag + thiolate units that build protection, the nanocluster shell, around the core. The nanoclusters are characterized by elemental analyses, XRD, ATR-FTIR, XPS, XAS, MALDI, ESI, UV-Vis and fluorescence measurements. The luminescent Ag15 (dodecanethiolate)11 ·2H2 O nanocluster is achieved in good yield after 4 hours of reaction whereas after 2 hours, the luminescent Ag35 (dodecanethiolate)16 is isolated. Both Ag nanoclusters present emission bands in the range 330–450 nm, the shifting depending on the excitation wavelength. This phenomenon is attributed to a possible dipolar state causing distribution in energies due to variability of dipole–dipole interactions. Moreover, both nanoclusters further present a NIR emission at about 700 nm independent from the excitation wavelength. Thanks to their optical and structural properties, the synthesized nanoclusters, perfect molecular/nanoparticle hybrids, have great potentiality for new applications in nanotechnologies.