0000000000005062
AUTHOR
Thalappil Pradeep
Atomically Precise Nanocluster Assemblies Encapsulating Plasmonic Gold Nanorods.
The self-assembled structures of atomically precise, ligand-protected noble metal nanoclusters leading to encapsulation of plasmonic gold nanorods (GNRs) is presented. Unlike highly sophisticated DNA nanotechnology, this strategically simple hydrogen bonding-directed self-assembly of nanoclusters leads to octahedral nanocrystals encapsulating GNRs. Specifically, the p-mercaptobenzoic acid (pMBA)-protected atomically precise silver nanocluster, Na4 [Ag44 (pMBA)30 ], and pMBA-functionalized GNRs were used. High-resolution transmission and scanning transmission electron tomographic reconstructions suggest that the geometry of the GNR surface is responsible for directing the assembly of silver …
Ag44(SeR)30: A Hollow Cage Silver Cluster with Selenolate Protection.
Selenolate protected, stable and atomically precise, hollow silver cluster was synthesized using solid state as well as solution state routes. The optical absorption spectrum shows multiple and sharp features similar to the thiolated Ag44 cluster, Ag44(SR)30 whose experimental structure was reported recently. High-resolution electrospray ionization mass spectrometry (HRESI MS) shows well-defined molecular ion features with two, three, and four ions with isotopic resolution, due to Ag44(SePh) 30. Additional characterization with diverse tools confirmed the composition. The closed-shell 18 electron superatom electronic structure, analogous to Ag44(SR)30 stabilizes the dodecahedral cage with a…
Gold Au(I)6 Clusters with Ligand-Derived Atomic Steric Locking: Multifunctional Optoelectrical Properties and Quantum Coherence
Funding Information: This work was supported by the ERC Advanced grant (DRIVEN, ERC‐2016‐AdG‐742829), the ERC grant (834742), the EU H2020‐MSCA‐RISE‐872049 (IPN‐Bio), the Academy of Finland's Centre of Excellence in Molecular Engineering of Biosynthetic Hybrid Materials Research (HYBER, 2014–2019), and Life‐Inspired Hybrid Materials (LIBER, 346108), Academy of Finland project fundings (No. 352900, 314810, 333982, 336144, 352780, 352930 and 353364), FinnCERES and Photonics Research and Innovation (PREIN) flagship programs. The authors acknowledge the provision of facilities and technical support by Aalto University OtaNano – Nanomicroscopy Center (Aalto‐NMC). | openaire: EC/H2020/834742/EU//…
Supramolecular functionalization and concomitant enhancement in properties of Au25 clusters
We present a versatile approach for tuning the surface functionality of an atomically precise 25 atom gold cluster using specific host-guest interactions between ?-cyclodextrin (CD) and the ligand anchored on the cluster. The supramolecular interaction between the Au25 cluster protected by 4-(t-butyl)benzyl mercaptan, labeled Au25SBB18, and CD yielding Au25SBB18�?�CDn (n = 1, 2, 3, and 4) has been probed experimentally using various spectroscopic techniques and was further analyzed by density functional theory calculations and molecular modeling. The viability of our method in modifying the properties of differently functionalized Au25 clusters is demonstrated. Besides modifying their optoe…
Ag11(SG)7 : A New Cluster Identified by Mass Spectrometry and Optical Spectroscopy
We report a one-step and high yield synthesis of a red-luminescent silver cluster with the molecular formula, Ag11(SG)7 (SG: glutathionate) via reduction of silver ions by sodium borohydride in the presence of the tripeptide, glutathione (GSH). The as-prepared cluster shows prominent absorption features at 485 and 625 nm in its UV-vis absorption spectrum. Aging of the as-prepared cluster solution led to the disappearance of the 625 nm peak, followed by broadening of the 485 nm peak to give three maxima at ?487, 437, and 393 nm in its absorption spectrum. These peaks remain unchanged even after polyacrylamide gel electrophoresis (PAGE), where a single band was observed confirming high purity…