CaSTL CCI Seminar Series 2019 - Karolina Sokolowska, University of Jyväskylä

Date: 
Thursday, June 13, 2019 - 13:00
Location: 
Zoom Meeting - LIVE BROADCAST on UC Irvine Campus in 2201 Nat Sci 2
Speakers: 
Karolina Sokolowska
Event Title: 
Monolayer Protected Clusters: Structurally Precise Building Blocks
Host: 
V. Ara Apkarian, Director CaSTL Center

__________________________________________________________________________________________________________

yesOnsite Location: 2201 Natural Sciences II Seminar Room

NOTE:  Zoom Meeting Live Broadcast (zoom.us) info below: 

Just launch (click) link below to join in!

https://zoom.us/j/127130761 

or Dial in option

+1 646 876 9923

+1 669 900 6833

Meeting ID: 127 130 761

___________________________________________________________________________________________________________________________________

BIO: Karolina Sokolowska is a third-year Chemistry PhD student supervised by  Adjunct  Professor  Tanja  Lahtinen  at  the  Nanoscience  Center, University  of  Jyväskylä.  Her  research  interest  center   around  gold nanoparticles, nanoclusters and their surface modification. They are excellent prototype systems to study quantum mechanical origin of plasmon and different types of plasmonic couplings. The research especially focuses on coupling through molecular bridges. Her goal is to learn how the ligand layer can be modified for different purposes, hopefully leading to novel applications. Her research interest involves application of advanced transmission electron microscopy (TEM) tools for characterization of nanoclusters and utilizing obtained knowledge for improving nanomaterials design."Monolayer Protected Clusters: Structurally Precise Building Blocks

 

Abstract: During the past few years, the field of nanoparticles has simply exploded with a huge potential for numerous important applications. However, it has become increasingly more evident that to understand the concept of many phenomena at quantum mechanical level in nanoscale systems, detailed knowledge of the atomic and electronic structures is necessary. In many nanoscopic systems, this is nearly impossible to achieve due to sheer size and distribution of products. In this regard, small (< 5nm) monolayer protected nanoparticles with exact atomic structure, similar to molecules, has enabled accurate studies of their chemistry, and are extremely important for deepening our understanding of the larger nanoparticle systems.1 Recently, we have developed a robust synthesis to create covalently linked individual nanoscale constructs from three atomically defined thiol-protected gold nanoparticles, showing emergence of plasmonic behavior.2 Building superstructures, with such a molecular precision enables studies of plasmonic coupling through molecular bridges at quantum mechanical level. Multimers of linked structures exhibit additional transitions in their UV-vis spectrum at 630 nm and 810 nm, indicating the presence of hybridized LSPR modes. The generality of the synthesis was proven by using various dithiol-linking molecules.3 Detailed analysis of reaction yields in combination with simulation suggested that superstructures are bound together by short chain of disulfide-bridged dithiol. More recently, we have performed STEM-EELS experiment to verify linking mechanism by observing a number of molecules between particles. This achievement of making well-defined metallic nanoscale superstructures opens new possibilities nanostructures in rational design of nanoscale devices with the precision of a single atom.

Figure 1. Covalently linked dimers of gold nanoclusters Au102(p-MBA)44.

[1] J. Phys. Chem. C, 2019, 123, 2602–2612
[2] Nanoscale, 2016, 8, 18665-18674.
[3] J. Phys. Chem. C, 2018, 122, 12524–12533.