Personal tools
You are here: Home Research Chemistry Coordination and Supramolecular Chemistry

Coordination and Supramolecular Chemistry

coordination-and-supramolecular-chemistry.jpg

The Coordination and Supramolecular Chemistry group designs and synthesizes new molecules for the selective uptake of anions, neutral molecules or metal ions for environmental and medical applications.  

 


 

Rita Delgado
Professor Associado com Agregação IST
PhD 1985 in Chemistry, Universidade Técnica de Lisboa (IST)

Phone (+351) 214469737 | Extension 1737
delgado@itqb.unl.pt

Lab Website

 

Research Interests

Recognition of anionic substrates is a vigorous research field due to the important role of anions in biological, industrial, and environmental fields. In this area, the design and synthesis of molecular receptors for the selective binding of anions is crucial. Our laboratory has contributed in the last years with the synthesis of new molecules having well-defined three-dimensional cavities capable to accommodate and selectively bind anionic or neutral substrates in aqueous solution. The strength of the association of both partners is evaluated by the determination of the binding constant by spectroscopic or potentiometric techniques. The new molecules, which act as receptors, are used for the detection and removal of anionic pollutants, or separation of amino acids or chiral drugs. They should selectively encapsulate the substrate, forming supermolecules, with high binding affinity based on the best fit between the partners bound through several and cooperative weak interactions. For the successful receptors, for which selectivity for a given substrate is achieved, analytical techniques for its detection or quantification in “real-life” samples will be developed. Small changes of the structure of such receptors can transform them in sensors and when attached to solid matrixes they can be used in chromatographic separations.

Another important area of interest in our laboratory deals with compounds capable to uptake certain metal ions and to hold them so strongly that they are not liberated in very adverse situations. These compounds, known by the name of chelators and chelate when bound to the metal ion, are useful in medical applications when bound to some radioactive metal ions in diagnose or in therapy of tumours. The chelate must be chemically stable under physiological conditions to avoid the release of toxic metal ions. Therefore such chelates should present high thermodynamic stability as well as strong kinetic inertness to dissociation. Moreover, when specific targeting is involved, the chelator must be easily functionalized with chemical groups or conjugated to biomolecules with high affinity and selectivity for specific molecular targets. As a general rule, a potential radiopharmaceutical must be prepared in quick and mild conditions, and should be widely stable in physiological media and present good chemical properties to ensure an efficient clearance from the body. Our laboratory has developed and studied some new macrocyclic chelators some of them exhibiting very interesting properties for this field. These chelators can also be useful in the removal of toxic metal ions from the body or the environment. 

 

Group Members

    • Nicolas Bernier, post-doc student
    • Luís Lima, PhD student 
    • Carla Cruz, PhD student
    • Pedro Mateus, PhD student

 

Selected Publications

  1. Mateus P., Delgado R., Brandão P. and Félix V. (2009). “Polyaza Cryptand Receptor Selective for Dihydrogen Phosphate.” J. Org. Chem., 74, 8638–8646.
  2. Cruz C., Calisto V., Delgado R. and Félix V. (2009). “Design of Protonated Polyazamacrocycles Based on Phenanthroline Motifs for Selective Uptake of Aromatic Carboxylate Anions and Herbicides." Chem. Eur. J., 2009, 15, 3277-3289.
  3. Delgado R., Félix V. Lima L. M. P. and Price, D. W. (2007). “Metal complexes of cyclen and cyclam derivatives useful for medical applications: a discussion based on thermodynamic stability constants and structural data.” Dalton Trans., 2734-2745. 

 

Laboratory's website

For further information please visit the laboratory's website 

 

Química de Coordenação e Supramolecular (PT)

No laboratório de Química de Coordenação e Supramolecular sintetizam-se novas moléculas que são usadas no reconhecimento de aniões ou outros substratos orgânicos. Nos últimos anos temos sintetizado moléculas com cavidades tridimensionais bem definidas onde se podem acomodar e fixar selectivamente aniões, ou até moléculas neutras, em solução aquosa. O objectivo deste trabalho é a detecção e remoção de poluentes aniónicos, ou a separação de aminoácidos ou drogas quirais. Os receptores têm de ser selectivos a um único substrato, o que se deseja detectar ou remover. O que se consegue com de uma complementaridade de forma e tamanho, mas também porque o substrato se fixa ao receptor através de múltiplas e cooperativas interacções.

Também sintetizamos moléculas capazes de agarrar certos iões metálicos com uma força tal que não os largam quando atravessam meios muito competitivos. Se os iões metálicos forem radioactivos, eles formam os chamados quelatos, que podem ser utilizados em meios diagnóstico ou mesmo em terapia de certos tumors. Os quelatos têm de ser quimicamente estáveis nos meios fisiológicos impedindo a libertação dos metais radioactivos, que são extremamente tóxicos. O nosso laboratório tem desenvolvido e sintetizado alguns agentes quelantes do tipo macrocíclico com propriedades interessantes para estas aplicações. Além disso, estes compostos podem também ser úteis na remoção de metais tóxicos de organismos vivos ou do ambiente. 

 

top

Document Actions