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Design of Novel Group 4 ansa-Metallocene Compounds and their Role as Catalysts in the Polymerization of Olefins
(2014-01-28) Prashar, Sanjiv; Gómez-Ruiz, Santiago; Fajardo, Mariano; Antiñolo, Antonio; Fernández-Galán, Rafael; Otero, Antonio; Rivilla, Iván
Since the discovery by Sinn and Kaminsky that zirconocene complexes in the presence of MAO were able to polymerize olefins there has been a dramatic expansion in this field. One of the main focuses of this research is centred on the tailoring of metallocene complexes that can direct the catalytic reaction in producing polymers with desired physical properties. Ligand design is therefore of utmost importance in the development of "made to measure" single-site olefin polymerization catalysts. In addition the introduction of functional groups in the ligand system can be later exploited in immobilizing the catalyst on different substrates. In this communication we describe the synthetic strategies used in the design of group four ansa-metallocene complexes and the application of these compounds as catalysts in the polymerization of ethylene and propylene. The principal design aims addressed include: 1. Variable substitution at the ansa-carbon bridging atom of the metallocene catalysts 2. Synthesis of hydride silylene ansa-bridged complexes that act as hydrosilylation reagents. 3. Functionalization of ansa-metallocene complexes 4. Synthesis of C1 symmetric ansa-metallocene catalysts which are isospecfic in the polymerization of propylene
Experiencia de innovación docente en la asignatura "Análisis Instrumental" curso 2009/10
(2011-11-24) Sierra Alonso, María Isabel; Pérez Quintanilla, Damian; Morante Zarcero, Sonia; Gómez Ruiz, Santiago; Gañán Aceituno, Judith; Sánchez Sánchez, Alfredo
Resultados de experiencia de innovación docente realizada en la asignatura Análisis Instrumental de segundo curso de Ingeniería Química en la URJC presentados a la II Jornada de Evaluación de Competencias en el Marco del EEES, celebrada en la ESCET (Móstoles, junio 2010)
Hydrosilylation in the Design and Functionalization of ansa-Metallocene Olefin Polymerization Catalysts
(2014-01-29) Gómez-Ruiz, Santiago; Prashar, Sanjiv; Fajardo, Mariano; Antiñolo, Antonio; Otero, Antonio
The group 4 ansa-metallocene complexes [M{Me(H)Si(¿5-C5Me4)(¿5-C5H4)}Cl2] (M = Ti, Zr, Hf),that contain a Si-H bond, have been used as hydrosilylation reagents with the silane substrates, Si(CH=CH2)4 and Me2Si(CH=CH2)2. Our results show that the hydrosilylation reaction takes place at only one of the vinyl groups to give [M{(CH2=CH)3SiCH2CH2(Me)Si(¿5-C5Me4)(¿5-C5H4)}Cl2] (M = Ti, Zr, Hf) and [M{(CH2=CH)Me2SiCH2CH2(Me)Si(¿5-C5Me4)(¿5-C5H4)}Cl2] (M = Ti, Zr, Hf). Hydrosilylation of the remaining vinyl groups can be achieved by using simple silane reagents, for example, HSiEt3 to give [M{(Et3SiCH2CH2)3SiCH2CH2(Me)Si(¿5-C5Me4)(¿5-C5H4)}Cl2] (M = Ti, Zr) and [M{(Et3SiCH2CH2)Me2SiCH2CH2(Me)Si(¿5-C5Me4)(¿5-C5H4)}Cl2] (M = Ti, Zr). All the compounds have been tested as homogeneous catalysts in the polymerization of ethylene and propylene
Novel synthetic approaches towards hexaazatriphenylene (HAT) derivatives
(Universidad Rey Juan Carlos-Universidad Complutense, 2008) Juárez, Rafael; Ramos, María Mar; Segura, José Luis
Large two-dimensional molecules with extended ¿-systems are subject of increasing interest as a consequence of their technological applications. In particular, hexaazatriphenylene (HAT) derivatives, present a great interest due to the influence of heteroatoms on the electronic nature without modifying the structure. HAT derivatives have recently attracted attention as materials for organic electronic applications1 and depending on the choice of substituent can have a variety of applications (discotic liquid-crystals, n-type semiconducting, magnetic materials or fluorescent dyes).2 Whereas HATs carrying six identical substituents are well known following different synthetic approaches, the synthesis of non-centrosymmetric HAT derivatives is still quite rare. In our working group we are centered in two main routes for affording HAT derivatives. One route affords a variety of symmetrical HAT derivatives including HAT condensed systems. On the other hand, we have also synthesized non-centrosymetric ¿-conjugated donor-acceptor molecules bearing a HAT core and donor groups in the periphery.3 In this communication we present a new soluble ¿-deficcient derivative which consists of three HAT molecules condensed around a central aromatic core so we have named it triHAT. We have found triHAT to be 0.75 V better acceptor than HAT in itself. We also present a new synthetic route in order to obtain non-centrosymetric ¿-conjugated donor-acceptor molecules bearing a HAT core and donnor groups in the periphery. This synthesis paves the way for further conjugated donnor-acceptor derivatives of HAT.
Nueva aplicación de materiales mesoporosos como adsorbente en MSPD para la determinación de hormonas esteroideas en leche de cabra por MECK
(2014-01-30) Silva López, Mariana; Gañán Aceituno, Judith; Morante Zarcero, Sonia; Pérez Quintanilla, Damián; Sierra Alonso, María Isabel
Se ha estudiado la aplicación de sílices mesoporosas para la determinación de hormonas en leche mediante dispersión de matriz en fase sólida y análisis por electroforesis capilar.
Synthesis of cationic niobocene imido derivatives
(2014-01-29) Hierro, Isabel del; Fajardo, Mariano; Garcés, Andrés; Gómez-Ruiz, Santiago; Pérez, Yolanda; Prashar, Sanjiv; Antiñolo, Antonio; Otero, Antonio; López-Mardomingo, Carmen
Following from our previous work in the synthesis and reactivity of niobium imido complexes,1 we have studied the preparation of cationic derivatives. The reduction of [Nb(=NPh)(eta5-C5H4SiMe3)2Cl] gives the short-lived niobocene(IV) radical [Nb(=NPh)(eta5-C5H4SiMe3)2. which was rapidly oxidized to the niobocene(V) cationic species [Nb(=NPh)(eta5-C5H4SiMe3)2(L)]+ (L = CO, ButNC) by the reaction with [Fe(eta5-C5H5)2][BPh4]. In a similar manner, the ansa-niobocene compound [Nb(=NBut){Me2Si(eta5-C5Me4)(eta5-C5H4)}(ButNC)][BPh4] was synthesized. However, in the attempted reduction of [Nb(=NBut){Me2Si(eta5-C5H4)2}Cl], the expected radical species was not observed. Instead the niobocene (V) imido dimer product was identified. The reaction with H2 and I2 gave [Nb(=NBut){Me2Si(eta5-C5H4)2}H] and [Nb(=NBut){Me2Si(eta5-C5H4)2}I], respectively.
Synthesis of new titanocene(IV) carboxylate complexes: an alternative chemotherapeutic treatment against cancer
(Departamento de Química Inorgánica y Analítica, E.S.C.E.T., Universidad Rey Juan Carlos, 2012-05) Ceballos Torres, Jesús; Caballero Rodríguez, María J.; Prashar, Sanjiv; Paschke, Reinhard; Steinborn, Dirk; Kaluderovic, Goran N.; Gómez Ruiz, Santiago

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