A5085669966- Gold and Silver Nanoparticles Synthesis and Applications
- Spectroscopy Techniques in Biomedical and Chemical Research
- Various Chemistry Research Topics
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Molecular Junctions and Nanostructures
- Spectroscopy and Quantum Chemical Studies
- Microfluidic and Capillary Electrophoresis Applications
- Analytical Chemistry and Chromatography
- Plasmonic and Surface Plasmon Research
- Quantum Dots Synthesis And Properties
- Advanced Fluorescence Microscopy Techniques
- Spectroscopy and Chemometric Analyses
- N-Heterocyclic Carbenes in Organic and Inorganic Chemistry
- Photoacoustic and Ultrasonic Imaging
- Advanced biosensing and bioanalysis techniques
- Integrated Circuits and Semiconductor Failure Analysis
- Metal complexes synthesis and properties
- Electrochemical Analysis and Applications
- Force Microscopy Techniques and Applications
- Nanotechnology research and applications
- Chemistry and Chemical Engineering
- Quantum and electron transport phenomena
- Protein Interaction Studies and Fluorescence Analysis
- Near-Field Optical Microscopy
Albright College
2014-2022
Northwestern University
2011-2015
An existence proof for single-molecule tip-enhanced Raman spectroscopy (SMTERS) is given using the frequency domain approach involving two isotopologues of Rhodamine 6G (R6G) that were previously employed surface-enhanced (SMSERS). A combination experimental and theoretical studies provides a detailed view isotopic response R6G–d0 R6G–d4 in 600 – 800 cm–1 region. The nature TERS experiment confirmed through lines evidence. First, vibrational signature only one isotopologue at time was...
Multiple vibrational modes have been observed for copper phthalocyanine (CuPc) adlayers on Ag(111) using ultrahigh vacuum (UHV) tip-enhanced Raman spectroscopy (TERS). Several important new experimental features are introduced in this work that significantly advance the state-of-the-art UHV-TERS. These include (1) concurrent sub-nm molecular resolution STM imaging Ag tips with laser illumination of tip-sample junction, (2) focusing and collection optics external to UHV-STM has two...
Tip-enhanced Raman spectroscopy (TERS) has experienced tremendous growth in the last 5 years. Specifically, TER imaging provided invaluable insight into spatial distribution and properties of chemical species on a surface with resolution that is otherwise unattainable by any other analytical method. Additionally, there been further development coupling ultrafast TERS hope obtaining both temporal nanometer-scale resolution. In this Perspective, we discuss several recent advances TERS,...
Tip-enhanced Raman spectroscopy (TERS) provides chemical information for adsorbates with nanoscale spatial resolution, single-molecule sensitivity, and, when combined scanning tunneling microscopy (STM), Ångstrom-scale topographic resolution. Performing TERS under ultrahigh-vacuum conditions allows pristine and atomically smooth surfaces to be maintained, while liquid He cooling minimizes surface diffusion of across the solid surface, allowing direct STM imaging. Low-temperature TER (LT-TER)...
An explanation of the relative intensity fluctuations observed in single-molecule Raman experiments is described utilizing both tip-enhanced spectroscopy and time-dependent density functional theory calculations. No correlation mode to indicating that changes intensities are completely independent. Theoretical calculations provide convincing evidence not result diffusion, orientation, or local electromagnetic field gradients but rather subtle variations excited-state lifetime, energy,...
Tip-enhanced Raman spectroscopy (TERS) can probe chemistry occurring at surfaces with both nanometer spectroscopic and submolecular spatial resolution. Combining ultrafast TERS allows for picosecond and, in principle, femtosecond temporal Here we couple an optical parametric oscillator (OPO) a scanning tunneling microscopy (STM)-TERS microscope to excite the tip plasmon excitation source. The plasmonic was not damaged OPO excitation, TER spectra were observed two resonant adsorbates. signal...
Tip-enhanced Raman spectroscopy (TERS) provides chemical information about adsorbates with nanoscale spatial resolution, but developments are still required in order to incorporate ultrafast temporal resolution. In this Letter, we demonstrate that a reliable TER signal of rhodamine 6G (R6G) using picosecond (ps)-pulsed excitation can be obtained ultrahigh vacuum (UHV). contrast our previous observation irreversible loss ambient TERS ( Klingsporn , J. M. ; Sonntag D. Seideman T. Van Duyne R....
We combine experiment, theory, and first-principles-based calculations to study the light-induced plasmon-mediated electron transport characteristics of a molecular-scale junction. The experimental data show nonlinear increase in electronic current perturbation when focus chopped laser beam moves laterally toward tip-sample To understand this behavior generalize it, we apply combined theory nonequilibrium formed upon decoherence an optically triggered plasmon first-principles calculations....
Electrophilic aromatic substitution (EAS) represents an important class of reactions taught in the undergraduate organic chemistry curriculum. The EAS reaction benzene and its substituted derivatives is generally described as proceeding through a carbocation (arenium cation) intermediate, regiochemistry product heavily influenced by nature substituents. Molecular properties such frontier molecular orbitals, Hirshfeld charges, 13C 1H NMR shifts can predict directing In this upper level...
ADVERTISEMENT RETURN TO ISSUEPREVAddition/CorrectionORIGINAL ARTICLEThis notice is a correctionCorrection to Observation of Multiple Vibrational Modes in Ultrahigh Vacuum Tip-Enhanced Raman Spectroscopy Combined with Molecular-Resolution Scanning Tunneling MicroscopyN. Jiang, E. T. Foley, J. M. Klingsporn, D. Sonntag, N. A. Valley, Dieringer, Seideman, G. C. Schatz, Hersam*, and R. P. Van Duyne*Cite this: Nano Lett. 2012, 12, 6506Publication Date (Web):November 9, 2012Publication History...
Recent advances in spectroscopy and computational chemistry facilitate the introduction of current spectroscopic methods at undergraduate level. Students obtain analyze experimental calculated vibrational spectra (infrared Raman) a set alkyne molecules to determine role symmetry with respect gross selection rules. The functional group should be well-known from organic well-resolved resonances frequencies familiar students. are able apply concepts symmetry, polarizability, molecular dipoles...
Computational chemistry techniques are used along with spectroscopy to characterize acetaminophen synthesized in an undergraduate laboratory experiment. The inclusion of electronic structure calculations provide infrared and Raman spectra the synthesis characterization connects over-the-counter medications which students familiar experience producing characterizing a compound, growing role computational chemical enterprise. visualization molecular motions associate absorption frequencies...
The synthesis and full characterization of a series neutral ligand α-diimine complexes aluminum are reported. compounds [Al(LAr)2Cl2)][AlCl4] [LAr = N,N′-bis(4-R-C6H4)-2,3-dimethyl-1,4-diazabutadiene] structurally analogous, as determined by multinuclear NMR spectroscopy solid-state X-ray diffraction, across range electron-donating [R Me (2), tBu (3), OMe (4), NMe2 (5)] electron-withdrawing Cl (6), CF3 (7), NO2 (8)] substituents in the aryl side arm ligand. UV–vis absorption electrochemistry...