Jenkins Group Published in Langmuir and Chemical Science

May 12, 2021 by Kayla Benson

The Jenkins Group published their work “Imidazolinium N-Heterocyclic Carbene Ligands for Enhanced Stability on Gold Surfaces” in Langmuir. This work explores the preparation and stability of NHC-coated gold surfaces using imidazolium and imidazolinium NHC ligands. X-ray photoelectron spectroscopy and surface-enhanced Raman spectroscopy demonstrate the attachment of NHC ligands to the gold surface and show enhanced stability of imidazolinium compared to the traditional imidazolium under harsh acidic conditions.

The Jenkins Group also published their work “Actinide tetra-N-heterocyclic carbene ‘sandwiches’” in Chemical Science. “We synthesized new “sandwich” complexes by placing two NHC macrocycles around a single actinide ion,” Jenkins said. “I am particularly excited about this paper since it is work that I began on my sabbatical at the University of Edinburgh almost four years ago.  It is the beginning of a new research area in my group, which is f-block NHC chemistry.” 

The complexes were characterized by a range of experimental methods and DFT calculations. X-ray crystallography confirms the geometry at the metal centre can be set by the size of the macrocyclic ring, leading to either square prismatic or square anti-prismatic shapes; the geometry of the latter is retained in solution, which also undergoes reversible, electrochemical one-electron oxidation or reduction for the uranium variant. DFT calculations reveal a frontier orbital picture that is similar to thorocene and uranocene, in which the NHC ligands show almost exclusively σ-donation to the metal without π-backbonding.

Jenkins Group Published in ACS Nano

August 19, 2020 by Kayla Benson

Research from the Jenkins Group was recently published in ACS Nano for their work “In Situ Monitoring of the Seeding and Growth of Silver MetalOrganic Nanotubes by Liquid-Cell Transmission Electron Microscopy“. Kristina Vailonis was one of the primary authors of this piece. Vailonis recently graduated with her PhD from the University of Tennessee’s Department of Chemistry.

Metal–organic nanotubes (MONTs)  are highly ordered one-dimensional crystalline porous frameworks. Despite being nanomaterials, virtually all studies of MONTs rely on characterization of the bulk crystalline material (micron-sized) by single-crystal X-ray diffraction.

This research analyzes their formations under a variety of reaction conditions in solution, and employ liquid-cell transmission electron microscopy (LCTEM), which allows the early stages of MONT assembly to be monitored in real time.

Changing the metal-to-ligand ratio alters the local concentrations of reactant monomers, resulting in multiple nucleation and growth pathways and diverse morphologies at the nanoscale.

“As we develop MONTs, it is critical to characterize them on the nanoscale before they have grown into bulk 3D materials that are microns in size,” said Jenkins “By collaborating with experts on liquid cell-TEM, we can observe the chemical reactions and watch these 1D materials grow in real time.”