Marta Saraiva


    Ongoing Project


  • Catalytic Activity of Molybdenum Complexes in the Presence of Different Ionic Liquids


  •    In the industry, the synthesis of 80% of the compounds produced require a catalytic reaction. Catalysts are compounds who are able to not only speed up the reaction but also redirect it to the formation of the desired product. These compounds can also be retrieved intact at the end of the reaction and be reutilized.
       In catalyst development, it is very important to consider both their activity and their selectivity, since a not selective catalytic system has no real use. The need for enantiomerically pure chiral compounds faces a continuous growth, promoted by the increase in the legal norm and health care, requiring efficient industrial processes for the pharmaceutical industry.
       Acting in response to this demand, an effort has been made in preparing catalysts that combine the advantages of the homogeneous catalysts (high activity) with the ones of the heterogeneous catalysts (high selectivity, easy separation, high thermal stability).
       The main aim of our work is to synthesize Mo(II) complexes of the general formulas [MoX(η3-C3H5)(CO)2L] and [MoX2(CO)2L] ( X = I, Cl, Br; L = bidentate ligands) with different ligands L and study their activity as homogeneous and heterogeneous catalysts. These families of complexes have proven to be good catalysts precursors, reacting with tertbutyl hydroperoxide (TBHP) to afford Mo(VI) dioxocounterparts, in various reactions, such as epoxidation of olefins. The preparation of the heterogeneous catalysts is made by immobilization of the complexes in different supports, such as silica, mesoporous materials, clays, among others. The mesoporous materials used are from the family of MCM materials, developed by Mobil, who have an ordered structure of hexagonal channels with diameters between 2 and 50 nm and high surface area. The immobilization of the complexes is made by their derivatization to react with the SiOH groups found on the surface of these materials.
       Our present work has been focused on testing the catalytic activity of molybdenum complexes in the presence of different ionic liquids to study the role of the biphasic catalysis. Furthermore, the immobilization in supported ionic liquid phases prepared with various catalyst/ionic liquid/support combinations will also be studied.



    CV


  • 2007 - Licenciatura in Chemistry, Faculdade de Ciências da Universidade de Lisboa.


  • 2008 - Masters in Chemistry, Faculdade de Ciências da Universidade de Lisboa.


  • 2012- PhD in Inorganic Chemistry, Universidade de Lisboa.



  • Publications


  • Marta S. Saraiva, Susana Quintal, Fátima C.M. Portugal, Telma A. Lopes, Vitor Félix, José M.F. Nogueira, Margarida Meireles, Michael G.B. Drew, Maria José Calhorda, Journal of Organometallic Chemistry 693 (2008) 3411-3418.


  • Marta S. Saraiva, Newton L. Dias Filho, Carla D. Nunes, Pedro D. Vaz, Teresa G. Nunes, Maria José Calhorda, Microporous and Mesoporous Materials 117 (2009) 670-677.


  • Marta S. Saraiva, Carla D. Nunes, Teresa G. Nunes, Maria José Calhorda, Journal of Molecular Catalysis A: Chemical 321 (2010) 92-100.


  • Daniel Bandarra, Miguel Lopes, Telma Lopes, Joana Almeida, Marta S. Saraiva, Maria Vasconcellos-Dias, Carla D. Nunes, Vitor Félix, Paula Brandão, Pedro D. Vaz, Margarida Meireles, Maria José Calhorda, Journal of Inorganic Biochemistry, Volume 104, Issue 11, November 2010, Pages 1171-1177.


  • Alysson S. Barreto, Adriano Aquino, Silvia C.S. Silva, Maria Eliane de Mesquita, M.J. Calhorda, M.S. Saraiva, Sandro Navickiene, Materials Letters 65 (2011) 1357-1359.


  • Ana Carina Ventura, Cristina I. Fernandes, Marta S. Saraiva, Teresa G. Nunes, Pedro D. Vaz and Carla D. Nunes, Current Inorganic Chemistry, 2011, Vol. 1, No. 2.


  • Nuno U. Silva, Cristina I. Fernandes, Teresa G. Nunes, Marta S. Saraiva, Carla D. Nunes, Pedro D. Vaz, Applied Catalysis A: General 408 (2011) 105- 116.


  • Marta S. Saraiva, Teresa Nunes, Carla D. nunes, Maria José Calhorda, Applied Catalysis A, General Volume 455, 30 March 2013, Pages 172-182.