ACS Summer School

The Reconquista River, the second most polluted river in Argentina, accumulates large amounts of organic matter and persistent toxic pollutants in its sediments. These conditions drive the selection of microorganisms with the potential to degrade contaminants and facilitate bioremediation. Notably, these microorganisms form biofilms on clay minerals, enabling them to survive under extreme conditions and alter the properties of the sediments.

Perylene, a polycyclic aromatic hydrocarbon (PAH), is characterized by its inherent rigidity, which imparts exceptional electronic and optical properties. This structural feature supports high fluorescence quantum yields, which are influenced by the nature of the substituents attached. Notably, substituents positioned in the bay or peri regions of the molecule significantly alter these properties, enabling fine-tuning of light emission across a broad spectrum of colors.

A novel statistical correlation method, MM-DP4+, was developed to enhance NMR-based molecular structure elucidation by significantly reducing computational costs through the use of MM-optimized geometries. A comprehensive evaluation of 36 theory levels identified SMD/ωB97XD/6-31+G**//MMFF as the most accurate and cost-effective approach, achieving 91% accuracy in stereochemical assignments. A Python-based software, DP4+App, was created to streamline the implementation of DP4+, MM-DP4+, and customizable DP4+ calculations via a user-friendly interface.

Water presents significant advantages when used in heterogeneous catalysis. Unlike traditional organic solvents, water is non-toxic, non-flammable, and readily available. Heterogeneous catalysts, which differ in state from the reaction medium, can be performed in water to facilitate various chemical reactions. For instance, micellar catalysis has proven effective for aminations, leveraging recyclable catalysts and aqueous reaction media to achieve high reactions yields of pharmaceutical APIs and complex targets.

In the following article we present a brief overview of the concept of mechanochemistry, a description of the history of the development of the concept, applications in organic synthesis, types of equipment, and advantages and disadvantages.

This poster highlights the background, history, and applications of heterogeneous catalysis.

Made by Evan Chen, Renata Bence and Luis López Rojas for the 2024 ACS GCI Green and Sustainable Chemistry Summer School.