Regional Issue "Organic Chemistry in Argentina" ARKIVOC 2011 (vii) 6-12
and we used one in the Department of Pharmacology. She struggled until she was able to buy the first spectrophotometer for the Department, and twenty years later, the stopped-flow instrument. Ingenious solutions and cooperation make up for the lack of equipment. Working together following a kinetic run in a home-made thermostat bath, we were able to take readings every 30 seconds on an analog single beam spectrophotometer.
Since she became a professor in FCQ, Rita had supervised fifteen doctoral theses, two master theses, postdoctoral students and several researchers of CONICET, the National Research Council of Argentina. Some of her students, like myself, remained at the Faculty as Professor; others became Professor in other Faculties of our country and abroad and others are working in industry. Rita’s investigations include physico-chemical studies and determination of organic reaction mechanisms, photochemistry, supramolecular chemistry, reactions in organized media, synthesis and green chemistry. She taught us all that both good ideas and hard work are required to be successful in research. As supervisor, she keeps a complete register of every experiment that her students have done. If she says: “I think that you have done an experiment with……” you better go and look for it because surely you have done it.
Her first investigations in kinetics in FCQ were related to aromatic nucleophilic substitutions. Among her achievements in those early days, the first example of base catalysis in the addition step in an aromatic nucleophilic substitution reaction should be mentioned. Some years later, two more students joined the group and investigations on acid-base catalysis, structure-reactivity correlations and nucleophilic substitution in weakly activated aromatic substrates were conducted. She also studied aromatic nucleophilic substitution reactions in which the leaving groups were secondary cyclic amines or primary amines finding that s-complexes formed by addition of the nucleophile to unsubstituted positions of the aromatic ring were important intermediates in the reaction.
More students and new ideas were incorporated in our group. At the beginning of the ’80’s, knowing the importance that supramolecular chemistry was acquiring, she began studies in this area using first cyclodextrins (CDs) and latter eritromycine as hosts. With the aim to demonstrate the influence of the formation of inclusion complexes with CDs on the reactivity and selectivity of organic reactions, studies on nucleophilic aromatic substitutions, electrophilic substitutions, photo- Fries rearrangements, competition elimination/substitution, cis-trans isomerization of azo compounds, hydrolysis of esters and amides of perfluoroalkylic acids were conducted. She also investigated the effect of CDs on the excited states of indole derivatives as well as the formation and decay of singlet oxygen in photochemical reactions. As CDs are used as models for enzymatic catalysis, hydrolysis reactions of esters and amides that show intramolecular catalysis were studied and it was demonstrated that CDs act in the same way as non competitive enzymatic inhibitors. In the last decade, ß-cyclodextrin esters of alkenyl succinic acids were synthesized in our labs. These amphiphilic cyclodextrins have the property to form micelles with two recognition sites, the cavity of the CD and the micelle core, and they can be incorporated in reverse micelles of AOT (sodium 1,4-bis(2-ethylhexyl)sulfosuccinate) in heptane.
Another interesting investigation in supramolecular chemistry was the formation of FeBr3-CD complexes in non-aqueous solution. These complexes are stable under ambient conditions, easy
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