Mini-courses

Title: Simultaneous fluorescence and absorbance spectroscopy: molecular-level chemical characterization and quantification without consumables.

Horiba

Horiba

Abstract:

Fluorescence, a phenomenon that captivates the human being, is the ability of a substance to emit light when subjected to certain external stimuli, such as chemical reactions, electromagnetic radiation, friction, or electricity. This phenomenon proves to be a valuable tool for the analysis and chemical characterization of various types of samples, as it allows researchers to obtain unique information from the light emitted by such samples.

The fluorescence technique encompasses a wide range of applications, making it possible to perform analyses in different modes and using a variety of accessories for specific study purposes. Some of these accessories include: integrating sphere, used to determine the quantum yield of emission; pulsed light sources for emission lifetime analysis; temporal resolution fluorescence analysis; excitation-emission matrix of fluorescence: allows simultaneous analysis of excitation and emission profiles of a sample; absorbance and transmittance analysis; chemical kinetics analysis, among others.

HORIBA introduces the latest Fluorescence measurement method: The technique is known as molecular fingerprinting A-TEEM, with A-TEEM standing for Absorbance-Transmission Excitation Emission Matrix, which is beginning to replace traditional analytical techniques such as HPLC and MS for certain industrial applications in QC/QA. This new A-TEEM technique provides true and traceable molecular fingerprints, as well as precise quantification. This presentation will provide interesting results in areas such as wine and spirits phenolics, pharmaceutical analysis, olive oil adulteration, water analysis, and PAH oil traces.

The versatility of fluorescence spectroscopy and A-TEEM technology makes them indispensable tools in various fields of knowledge, such as pharmacology, photovoltaic energy, material studies like graphene, cell and nanoparticle research, and contributes to advancements in energy conversion. Its application allows for detailed investigations, providing crucial details in chemical and physical phenomena, significantly contributing to scientific and technological progress across various disciplines.


Title: LS and jj Atomic Spectroscopic Terms and Spectroscopic Terms for small molecules

Chemistry Institute – Federal University of Rio de Janeiro – UFRJ, Brazil.

Abstract

Spectroscopic terms, according to the Russell-Saunders (LS) coupling, are the basic language to indicate the energy levels of isolated atoms and are therefore widely used in discussions of atomic spectra. This language is also widely used in discussions of electronic spectra of coordination compounds, being the starting point for the construction of correlation diagrams, Orgel diagrams, and Tanabe-Sugano diagrams. It turns out that for heavier atoms, the spin-orbit coupling becomes greater than the electron-electron interaction energy, making the LS description of the atomic energy levels incorrect. For these heavier atoms the jj coupling is more appropriate. Therefore, the objectives of this short course are: 1) present the Douglas and McDaniel method (much more practical than the methods found in most books) for obtaining spectroscopic terms according to LS coupling; 2) determination of spectroscopic terms according to jj coupling (more appropriate for the heaviest elements); 3) determination of spectroscopic terms for small molecules such as dioxygen, dinitrogen, and water, based on their molecular orbital diagrams. Thus, the content of this course finds application in the atomic spectroscopy of light and heavy elements, and in the electronic spectra of coordination compounds.

Course Program (short version): Spectroscopic terms according to LS coupling (Russell-Saunders). Spectroscopic terms according to jj coupling. Selection rules for electronic transitions. Spectroscopic terms for molecules

Course Program (full version)

1. Spectroscopic terms according to LS coupling (Russell-Saunders)

– Term symbol notation

– Vector model

– Douglas and McDaniel method

– Spectroscopic terms for the electronic configurations p2 and d2

– Hund’s rules

– Landé interval rule

– Spectroscopic terms for the electronic configuration d3

LS coupling and the NIST energy level tables for carbon, titanium, and vanadium

– Spectroscopic terms for the electronic configuration s1d1 (non-equivalent electrons)

2. Spectroscopic terms according to jj coupling

– Term symbol notation

– Spectroscopic terms for the electronic configuration p2

– Comparison between LS and jj coupling for the elements of the carbon group (Group 14)

– Hund’s rules for jj coupling

– Spectroscopic terms for the electronic configuration p3

– Comparison between LS and jj coupling for elements of the nitrogen group (Group 15)

– Comparison between LS and jj coupling for elements in the oxygen group (Group 16)

– Spectroscopic terms for the electronic configuration s1p1 (non-equivalent electrons)

3. Selection rules for electronic transitions following the LS and jj coupling

LS coupling: application to the carbon emission spectrum

jj coupling

4. Spectroscopic terms for molecules

– Dioxygen (O2)

– Dinitrogen (N2)

– Water