Discipline: Chemistry and Chemical Sciences
Subcategory: Chemistry (not Biochemistry)
Session: 4
Arnaldo Torres Hernandez - Pontifical Catholic University of Puerto Rico
Co-Author(s): Alexy Padilla Andújar, Pontifical Catholic University of Puerto Rico, Ponce PR; Carlos Echevarria Maldonado, Pontifical Catholic University of Puerto Rico, Ponce PR; Nicole Torres Colón, Pontifical Catholic University of Puerto Rico, Ponce PR; José Santiago Mass, Pontifical Catholic University of Puerto Rico, Ponce PR
Hydroquinones and catechols are widely known because of its use in the synthesis of drugs, antioxidants, dyes, agrochemicals, and perfumes. In addition, these compounds have been researched because they possess unique chemical characteristics and can be used as part of the production of self-assembled monolayers (SAMs). SAMs is an aggrupation of molecules on a metal surface that can be useful for investigating the electrons transfers in electrodes and biosensors. The hydroquinone analogs are added to the metal with a different number of thioalkylated chains length as part of theirs structure, this carbon chain is crucial for the electrochemical response in monolayers, the transfer of electrons on the surface of the electrodes, and even the protection of the metal where the compound is adsorbed. The purpose of this research project was synthesizing hydroquinone and catechol compounds to study their electrochemical behavior, to gain understanding about the relative strength and type of chemisorption, and to comprehend dynamics of ligands displacement at the solid-liquid interface on electrodes. It is expected that the longer the chain, the better the electrochemical behavior and higher surface coverage. The hydroquinone analogs were prepared by adding the corresponding dibromoalkane chain group (3,5,6,9 and 11) to 1,4-dimethoxybenzene in THF and under nitrogen atmosphere. Demethylation, bromine substitution, and acidification were needed to achieve the desire molecules. The pentalkylated brominated hydroquinone was synthesized with a percent yield of 71%. In addition, a benzylated group was incorporated into 1,2-dimethoxybenzene for the catechol analogs. Catecol analogs such as Bis(3,4-dihydroxyphenyl)methanone (BDHPmethanone), BDHPmethane, BDHPmethanol, were achieved with a 33%, 96%, and 21% respectively. Compounds synthesis was successfully achieved with the mixture of reagents, followed by extractions, concentration under reduce pressure, and finally the purification by silica gel chromatography. Quantitative and qualitative analyzes of analogs were obtained by characterization by Proton Nuclear Magnetic Resonance (1HNMR), Infrared Spectroscopy (IR), retardation factor, and melting point. The study of these compounds will bring improvements in instruments such as electrodes that are used to measure conductivity for different purpose and biosensors for the detection of diseases.
Funder Acknowledgement(s): This research project was supported by the Puerto Rico Louis Stokes Alliance For Minority Participation (PR-LSAMP) in collaboration with the NSF
Faculty Advisor: Adalgisa Batista Parra, abatista@pucpr.edu
Role: The total synthesis of the compounds, purification, and characterization by NMR and IR.