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  • Vitor Joo Salgueiro Rosa

    SYNTHESIS, CHARACTERIZATION AND

    REACTIVITY OF NEW COBALT,

    PALLADIUM AND NICKEL COMPLEXES

    BEARING

    -DIIMINES AND P,O LIGANDS

    Lisboa

    2008

  • copyright

  • Vitor Joo Salgueiro Rosa

    SYNTHESIS, CHARACTERIZATION AND

    REACTIVITY OF NEW COBALT,

    PALLADIUM AND NICKEL COMPLEXES

    BEARING

    -DIIMINES AND P,O LIGANDS

    Dissertao apresentada para a obteno do

    Grau de Doutor em Qumica,

    Especialidade Qumica Inorgnica

    Pela Universidade Nova de Lisboa,

    Faculdade de Cincias e Tecnologia

    Lisboa

    2008

  • Posso ser to mau como os piores mas, graas

    a Deus, tambm posso ser to bom como os melhores

    Walt Whitman American poet (1819-1892)

    our knowledge can be only finite, while

    our ignorance must necessarily be infinite.

    Karl Popper British philosopher of science (1902-1994)

  • Ao Toms

  • Acknowledgements

    Vitor Joo Salgueiro Rosa iii

    ACKNOWLEDGEMENTS

    To Prof. Teresa Avils, the supervisor of this thesis, for all her help and guidance

    through this work, and her truly friendship. For providing motivation and help to allow me to

    overcome the frustration that usually strikes synthetic chemists. I would like to thank her also

    for the help and criticism during the making of this thesis.

    To Dr. Carlos Lodeiro, for his always useful advices and support, and for his input in

    absorption studies.

    To Prof. Richard Welter, for all the help in the determination of single crystals X-ray

    structures, his patience and friendship.

    To Prof. Teixeira Gomes to helping me at the beginning of this journey that was this

    thesis, for the polymerization of ethylene tests and for the pleasant collaboration we had and

    hoping that it continues.

    To Berta Covelo for X-ray studies, Prof. Carlos Brondino for the EPR studies, Prof.

    Gabriel Aulln for the theoretical studies and Pierre Braunstein for his useful chemical

    insights and collaboration.

    To Fundao para a Cincia e a Tecnologia, for financial support through the

    PRAXIS XXI program, with the grant SFRH/BD/13777/2003.

    To the New University of Lisbon and in particular the Chemistry Department of the

    Faculty of Science and Technology, for giving me the possibility to access and use the

    technical, material and human resources, in particular the assistance of Dr. Maria do Rosrio

    Caras Altas in recording the NMR data.

    To Christophe, Jean-Thomas and Samuel and Magno for their friendship and all the

    help they provided me at Strasbourg.

    To all my laboratory colleagues, in particular Bruno, Betty and Tiago for their

    kindness, and to all my friends, in particular Jorge for his help in the revision of this thesis

    and his constant support.

    And finally, thanks to my family, in particular my mother without whom I would

    never be who I am.

  • Abstract

    Vitor Joo Salgueiro Rosa v

    ABSTRACT

    This work describes the synthesis and characterization of a series of new -diimine

    and P,O, -keto and acetamide phosphines ligands, and their complexation to Ni(II), Co(II),

    Co(III) and Pd(II) to obtain a series of new compounds aiming to study their structural

    characteristics and to test their catalytic activity. All the compounds synthesized were

    characterized by the usual spectroscopic and spectrometric techniques: Elemental Analysis,

    MALDI-TOF-MS spectrometry, IR, UV-vis, 1H, 13C and 31P NMR spectroscopies. Some of

    the paramagnetic compounds were also characterized by EPR. For the majority of the

    compounds it was possible to solve their solid state structure by single crystal X-ray

    diffraction. Tests for olefin polymerization were performed in order to determine the catalytic

    activity of the Co(II) complexes.

    Chapter I presents a brief introduction to homogenous catalysis, highlighting the

    reactions catalyzed by the type of compounds described in this thesis, namely olefin

    polymerization and oligomerization and reactions catalyzed by the complexes bearing -

    diimines and P,O type ligands.

    Chapter II is dedicated to the description of the synthesis of new -diimines cobalt

    (II) complexes, of general formula [CoX2(-diimine)], where X = Cl or I and the -diimines

    are bis(aryl)acenaphthenequinonediimine) (Ar-BIAN) and 1,4-diaryl-2,3-dimethyl-1,4-diaza-

    1,3-butadiene (Ar-DAB). Structures solved by single crystal X-ray diffraction were obtained

    for all the described complexes. For some of the compounds, X-band EPR measurements

    were performed on polycrystalline samples, showing a high-spin Co(II) (S = 3/2) ion, in a

    distorted axial environment. EPR single crystal experiments on two of the compounds

    allowed us to determine the g tensor orientation in the molecular structure.

    In Chapter III we continue with the synthesis and characterization of more cobalt (II)

    complexes bearing -diimines of general formula [CoX2(-diimine)], with X = Cl or I and -

    diimines are bis(aryl)acenaphthenequinonediimine) (Ar-BIAN) and 1,4-diaryl-2,3-dimethyl-

    1,4-diaza-1,3-butadiene (Ar-DAB). The structures of three of the new compounds synthesized

    were determined by single crystal X-ray diffraction. A NMR paramagnetic characterization of

  • Abstract

    vi Vitor Joo Salgueiro Rosa

    all the compounds described is presented. Ethylene polymerization tests were done to

    determine the catalytic activity of several of the Co(II) complexes described in Chapter II

    and III and their results are shown.

    In Chapter IV a new rigid bidentate ligand, bis(1-naphthylimino)acenaphthene, and

    its complexes with Zn(II) and Pd(II), were synthesized. Both the ligand and its complexes

    show syn and anti isomers. Structures of the ligand and the anti isomer of the Pd(II) complex

    were solved by single crystal X-ray diffraction. All the compounds were characterized by

    elemental analysis, MALDI-TOF-MS spectrometry, and by IR, UV-vis, 1H, 13C, 1H-1H

    COSY, 1H-13C HSQC, 1H-13C HSQC-TOCSY and 1H-1H NOESY NMR when necessary.

    DFT studies showed that both conformers of [PdCl2(BIAN)] are isoenergetics and can

    be obtain experimentally. However, we can predict that the isomerization process is not

    available in square-planar complex, but is possible for the free ligand. The molecular

    geometry is very similar in both isomers, and only different orientations for naphthyl groups

    can be expected.

    Chapter V describes the synthesis of new P, O type ligands, -keto phosphine,

    R2PCH2C(O)Ph, and acetamide phosphine R2PNHC(O)Me, as well as a series of new cobalt

    (III) complexes namely [(5-C5H5)CoI2{Ph2PCH2C(O)Ph}], and [(5-

    C5H5)CoI2{Ph2PNHC(O)Me}]. Treating these Co(III) compounds with an excess of Et3N,

    resulted in complexes 2-phosphinoenolate [(5-C5H5)CoI{Ph2PCHC(O)Ph}] and 2-

    acetamide phosphine [(5-C5H5)CoI{Ph2PNC(O)Me}]. Nickel (II) complexes were also

    obtained: cis-[Ni(Ph2PNC(O)Me)2] and cis-[Ni((i-Pr)2PNC(O)Me)2]. Their geometry

    and isomerism were discussed. Seven structures of the compounds described in this chapter

    were determined by single crystal X-ray diffraction.

    The general conclusions of this work can be found in Chapter VI.

  • Resumo

    Vitor Joo Salgueiro Rosa vii

    RESUMO

    Neste trabalho descreve-se a sntese e caracterizao de uma srie de novos ligandos,

    do tipo -diimina e do tipo P,O, -keto e acetamido fosfina, e a sua complexao a Ni(II),

    Co(II), Co (III) e Pd(II) obtendo-se sries de novos compostos com o objectivo de estudar as

    suas caractersticas estruturais e testar a sua actividade cataltica. Todos os compostos

    sintetizados foram caracterizados pelos mtodos espectroscpicos e espectromtricos usuais:

    anlise elementar, espectrometria MALDI-TOF-MS, e espectroscopias de IV, UV-vis, 1H, 13C

    e 31P RMN. No caso de alguns dos compostos paramagnticos foi tambm utilizada RPE. Na

    maioria dos compostos foi possvel determinar as estruturas no estado slido por difraco de

    raios-X. Foram efectuados testes de catlise de polimerizao de etileno para determinar a

    actividade de vrios dos complexos de Co(II).

    No Captulo I feita uma breve introduo catlise homognea, salientando as

    reaces catalizadas pelo tipo de compostos descritos nesta tese, nomeadamente a

    polimerizao e oligomerizao de olefinas e reaces catalizadas pelos complexos contendo

    ligandos -diiminicos e do tipo P,O.

    O Captulo II est dedicado descrio da sntese de novos complexos de cobalto (II)

    com ligandos -diiminas, de formula geral [CoX2(-diimina)], nos quais X = Cl ou I e as -

    diiminas so a bis(arilo)acenaftenoquinonadiimina) (Ar-BIAN) e a 1,4-diaril-2,3-dimetil-1,4-

    diaza-1,3-butadieno (Ar-DAB). Foi possvel obter estruturas atravs da difraco de raios-X

    de todos os complexos descritos. Medidas de RPE banda X com amostras policristalinas

    foram feitas nalguns dos compostos descritos mostrando um spin-alto do io Co(II) (S = 3/2)

    num ambiente axialmente distorcido. Experincias de RPE de mono cristal, de dois dos

    compostos, permitiram-nos determinar a orientao do tensor g dentro da estrutura molecular.

    No Captulo III continua-se a descrio da sntese de complexos de cobalto (II) com

    -diiminas de formula geral [CoX2(-diimina)], nos quais X = Cl ou I e as -diiminas so a

    bis(arilo)acenaftenoquinonadiimina) (Ar-BIAN) e a 1,4-diaril-2,3-d