M. Mhamad Aly Moussawi

219 Pages·2017·19.27 MB·English

by  Frédéric Mazaleyrat

Assemblages à base de

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polyoxométallates : des
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A interactions fondamentales aux
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0 matériaux hybrides
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:

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supramoléculaires
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Thèse de doctorat de l'Université Paris-Saclay
préparée à Université de Versailles-Sanit-Quentin-en-Yvelines

École doctorale n°571 Sciences chimiques : Molécules, Matériaux,
Instrumentation et Biosystèmes
Spécialité de doctorat: Chimie

Thèse présentée et soutenue à Versailles, le 25 octobre 2017, par

M. Mhamad Aly Moussawi

Composition du Jury :

Mme. R. Meallet-Renault
Professeur, Université Paris-sud Présidente
M. C. Bo
Professeur, Institut Català d’Investigació Química Rapporteur
M. M. Sollogoub
Professeur, Université Pierre et Marie Curie Paris 6 Rapporteur
M. J. P. Mahy
Professeur, Université Paris-sud Examinateur
M. B. Hasenknopf
Professeur, Université Pierre et Marie Curie Paris 6 Examinateur
M. M. Haouas
Chargé de recherche, Université de Versailles Co-Directeur de thèse
M. S. Floquet
Maître de conférences, Université de Versailles Directeur de thèse, Invité
M. E. Cadot
Professeur, Université de Versailles Co-Encadrant, Invité

Acknowledgements
At the end of three astonishingly unforgettable years, I would like to thank everyone who
contributed in one way or another to the success of this work. First and foremost, I would like to
thank the jury members for accepting to evaluate this work: Prof. Carles Bo, Prof. Matthieu
Sollogoub, Prof. Jean-Pierre Mahy, Prof. Rachel Meallet-Renault, and Prof. Bernold Hasenknopf.
I would like to express my sincere gratitude to my co-directors and mentors, Sébastien Floquet
and Mohamed Haouas, for giving me the chance to work on this project. Your enthusiasm and
encouragement in good times and in bad will always be appreciated. Thank you for inspiring my
research and allowing me to grow as a scientist. Had it not been for your patience and those
numerous discussions, I wouldn’t have been as fortunate to be where I am today. Simply, if it
weren’t for you, I wouldn’t have had the chance to embark on this journey and experience the
sweet taste of fruitful efforts.
In other respects, I would like to express my profound appreciation for my co-supervisor
Emmanuel Cadot, or as I like to call him: “BOSS”. I’m deeply and eternally grateful for the
tremendous amount of time and effort you’ve put into this project. Although it was never easy
working with the perfectionist within you, I’m honestly thankful for him forcing me to never
accept anything less than whole. Your passion for research and your unwavering vision are truly
inspiring, even contagious. With your supervision and guidance, I managed to turn the tide every
single time. Your counsel has been the cornerstone I leaned on for support throughout my
odyssey. I thank my luck I had the chance to work with you.
What I have been vainly trying to convey with words doesn’t come close to expressing the
amount of admiration I hold for all three of you. I genuinely can’t find enough words to thank
you as I must and you deserve.
My heartfelt thanks go to Emmanuel Guillon, William Shepard, and David Landy for their great
contribution in various parts of this work and for giving me the chance to learn from their
astounding expertise.
I’m thankful for Nathalie Leclerc and Jérôme Marrot, the shadow soldiers behind the success of
every project; it was a pleasure working with such incredibly talented individuals. I learned a
i
great deal from you, and I couldn’t have done it all without your help and support. Marc
Lepeltier, I know you’re not holding your breath awaiting my recognition, but thanks for the
wondrous company you granted me during my stay and for the invaluable discussions on each
and everything in the world, literally everything. Eddy Dumas, the kind-hearted mean friend, I
don’t know if I am a friend of yours, but you are certainly one of mine. I can’t neglect mentioning
Pierre Mialane, Anne Dolbecq, Corine Simonnet, Catherine Roch, and Olivier Oms for being
such lovely engaging people and always making me feel welcomed.
Pavel, although you were there for only a brief period, you were an inspiration. I’m indebted for
you teaching me the basics of crystallography and thankful for the insight you provided me with
on polyoxometalates. Every discussion with you has proven to be worthwhile and rewarding.

During my stay in Versailles, I was also fortunate to make a lot of friends. I am glad I met each
and every one of you guys. William, Nancy, and Hala were there since day one, supporting and
helping me in every way possible. Amandine, thank you for keeping me company for the past
two years. You’re a great person to be around, but not when you’re having mood swings. I hate
you then (you know I’m just kidding my dearest of friends). Manal, thank you for your
encouragement, compassion, and the times we spent arguing and discussing ideas. I hope you
reach what you’re aiming for. Irene, I treasure your kindness and the way you care about others,
it’s truly heartwarming. Quentin, my officemate and the friend I can count on, it’s going to be a
long journey, but hang in there buddy; if I could do it, then so can you. It is said that true friends
are never of the same height, which is the case with me and Grégoire who shares my passion for
food. This has brought us even closer as friends and guaranteed that we always have something to
talk about. Arcadie, besides Marc, you are the only friend that I can discuss football with. Thank
you for being there. I’m also thankful to Dolores and all the help she provided as a scientist and a
friend. I can’t pretermit the people from the organic groups with whom I shared lunch every day:
Loic, Hamza, Maxime, Benjamin, Sylvain, Olivier, Talia, and other PhDs and students from ILV
who were of exceptional company.
I was also blessed to have friends outside the lab, amazing people with whom I shared countless
evenings and memorable trips: Ali, Raef, Mohammad S., Mohammad R., Ranin, Dina, Rana, and
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Tourine. Not forgetting my friends back home, who are more like family than friends: Lolwa,
Mahmoud, Ali, Mohamad and all the others who are too many to count.
To the man who never believed in me, to my father; and to my 10th grade chemistry teacher who
thought I was not good enough to study chemistry. I have to thank you because proving you
wrong has been my greatest incentive. Thanks again for providing me with the challenge I set out
to conquer.
To my family, the people who never stopped believing in me, thank you for the unconditional
love and support. To my grandparents, aunts and uncles with whom I grew up, thank you for
instilling in me compassion, forgiveness and the love for others, for making me believe that the
best way to predict the future is to create it myself, and that education makes the possibilities
endless. Finally, to my mother and sisters, mere words can’t begin to unravel how much you
mean to me, but I promise to not let you down and to always be by your side whenever needed.

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Do not love half lovers
Do not entertain half friends
Do not indulge in works of the half talented
Do not live half a life and do not die a half death
If you choose silence, then be silent
When you speak, do so until you are finished
Do not silence yourself to say something
And do not speak to be silent
If you accept, then express it bluntly
Do not mask it
If you refuse then be clear about it
for an ambiguous refusal
is but a weak acceptance
Do not accept half a solution
Do not believe half truths
Do not dream half a dream
Do not fantasize about half hopes
Half a drink will not quench your thirst
Half a meal will not satiate your hunger
Half the way will get you no where
Half an idea will bear you no results
Your other half is not the one you love
It is you in another time yet in the same space
It is you when you are not
Half a life is a life you didn't live,
A word you have not said
A smile you postponed
A love you have not had
A friendship you did not know
To reach and not arrive
Work and not work
Attend only to be absent
What makes you a stranger to them closest to you
and they strangers to you
The half is a mere moment of inability
but you are able for you are not half a being
You are a whole that exists
to live a life not half a life

Gibran Khalil Gibran
In the memory of my grandfather whom we lost last November; it still breaks my heart to have
not been around for your last days. I hope I’m making you proud.

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Abstract
In this work, we report in the first part the substitution of molybdenum by tungsten within
Keplerate-type anions, [{Mo } Mo O E (AcO) ]42- (E = O or S). Introducing tungsten to the
6 12 30 312 60 30
synthesis medium resulted in the isolation of a series of compounds, [{W Mo
x 6-
} Mo O E (AcO) ]42-, with variable metal content within their pentagonal units {M }. The
x 12 30 312 60 30 6
isolated products were characterized in solid state and in solution using different techniques. An
outstanding observation revealed the selective occupation of the central position in the
pentagonal unit by the W atoms. This revelation was stretched to reach other historical structures
as Mo-blue wheel [Mo O H (H O) ]14- and Krebs [Mo O (H O) ]8- anions that also
154 462 14 2 70 36 112 2 16
showed the same preferential occupation of W atoms for the heptacoordinated site, at the center
of the pentagon. Numerous techniques were employed to assess this regioselective substitution
process as high field NMR, X-ray diffraction and EXAFS.
In the second part, we focus on the fabrication of a three-component hybrid material based on
polyoxometalates (POMs), metallic clusters and -cyclodextrin (-CD). Investigation of such
material has been conducted using bottom-up approach by investigating the specific interactions
between CD and both types of inorganic units. Their ability to interact has been investigated in
the solid state by single-crystal X-ray diffraction and in solution using multinuclear NMR
methods (including DOSY, EXSY and COSY), ESI-mass and UV-Vis spectroscopies,
electrochemistry and ITC experiments. Single-crystal XRD analysis reveals that POM:γ-CD
constitutes a highly versatile system which gives aggregates with 1:1, 1:2, and 1:3 stoichiometry.
Surprisingly, these arrangements exhibit a common feature wherein the γ-CD moiety interacts
with the Dawson-type POMs through its primary face. We present also the first structural model
involving an octahedral-type metallic cluster with γ-CD. XRD study reveals that the cationic
[Ta Br (H O) ]2+ ion is closely embedded within two γ-CD units to give a supramolecular
6 12 2 6
ditopic cation, suitable to be used as a linker within extended structure. Solution study
demonstrates clearly that pre-associations exist in solution, for which binding constants and
thermodynamic parameters have been determined, giving preliminary arguments about the
chaotropic nature of the inorganic ions. Finally, the three components associate together to give a
well ordered polymer-like hybrid chain that is derived as hydrogel and single crystals.
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In the last part, we extend the CD-POM investigation to reach giant POM structures as the Mo-
blue ring. A non-conventional complexation results from this interaction explained by the
encapsulation of the organic macrocycle (CD) within the inorganic torus (POM). Increasing the
complexity of the system by introducing a third species, e.g. Keggin- or Dawson-type POM, or
octahedral cluster, provoked the formation of hybrid supramolecular assembly based on the
hierarchical arrangement of organic and inorganic molecules. Such nanoscopic onion-like
structure has been characterized by single-crystal X-ray diffraction thus demonstrating the
capability of the giant inorganic torus to develop relevant supramolecular chemistry and the
strong affinity of the inner and outer faces of the -CD for the polyoxometalate surfaces.
Furthermore, interactions and behavior in solution have been studied by multinuclear NMR
spectroscopy which supports specific interactions between different units. The formation of this
three-component hybrid assembly from one-pot procedure, in water and from nearly
stoichiometric conditions is discussed in terms of the driving forces orchestrating this highly
efficient multi-level recognition process. Finally, combining the concept of mixed Mo/W
pentagon-based POM with the hierarchical system generated a mesmerizing architecture.

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Résumé
Dans ce travail, nous présentons dans la première partie la substitution du molybdène par du
tungstène dans les anions de type Keplerates, [{Mo } Mo O E (AcO) ]42- (E = O or S).
6 12 30 312 60 30
L'introduction du tungstène dans le milieu de synthèse a entraîné l'isolement d'une série de
composés, [{W Mo } Mo O E (AcO) ]42-, avec une teneur en métal variable dans leurs
x 6-x 12 30 312 60 30
unités pentagonales {M }. Les produits isolés ont été caractérisés à l'état solide et en solution en
6
utilisant différentes techniques. Une observation remarquable a révélé l'occupation sélective de la
position centrale dans l'unité pentagonale par les atomes W. Cette observation a été étendue à
d'autres structures telles que les roues du bleu du molybdène [Mo O H (H O) ]14- et l’anion
154 462 14 2 70
Krebs [Mo O (H O) ]8- qui ont également montré la même occupation préférentielle des
36 112 2 16
atomes W pour le site héptavalent, au centre du pentagone. De nombreuses techniques ont été
employées pour évaluer ce processus de substitution regiosélective telle que la RMN à hauts
champs, la diffraction des rayons X et EXAFS.
Dans la deuxième partie, nous nous concentrons sur l’élaboration d'un matériau hybride à trois
composantes à base de polyoxométallates (POM), de clusters métalliques et de γ-cyclodextrine
(γ-CD). La conception de ce matériau suivant une approche synthétique basée sur la propagation
à l’infini des interactions spécifiques entre la CD et les deux types d'unités inorganiques, donnant
lieu à des chaines polymériques hybrides. Leur capacité à interagir mutuellement a été étudiée à
l'état solide par diffraction des rayons X (DRX) sur monocristal et en solution en utilisant des
méthodes de spectroscopie RMN multinucléaire et UV-Vis, spectrométrie de masse (ESI), ainsi
que des expériences d'électrochimie et d'ITC. L'analyse par DRX sur monocristal révèle une
diversité structurale du système POM:γ-CD conduisant à des agrégats de stoechiométrie variable
de type 1:1, 1:2 et 1:3. De façon remarquable, ces arrangements présentent une caractéristique
commune dans laquelle la fraction -CD interagit avec les POMs de type Dawson à travers sa
face frontale. Nous présentons également le premier modèle structural impliquant un cluster
métallique de type octaédrique avec γ-CD. L'étude par DRX révèle que l'ion cationique [Ta Br
6 12
(H O) ]2+ est intimement intégré dans les cavités de deux unités γ-CD pour donner un cation
2 6
ditopique supramoléculaire, que l’on peut utiliser comme agent liant pour la conception des
structures étendues. L'étude en solution démontre clairement que ces associations sont stables en
solution, et les constantes d’association ainsi que les paramètres thermodynamiques des
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complexes d’inclusion ont été déterminés. Les forces motrices des telles associations fortes sont
discutées notamment l’effet chaotropique des ions inorganiques. Enfin, les trois composants, CD,
POM et cluster, s'associent pour donner une chaîne hybride de type polymère bien ordonnée,
sous forme d’un hydrogel ou des monocristaux.
Dans la dernière partie, nous étendons l’étude des interactions CD-POM aux structures POMs
géantes telle que l’anneau du bleu du molybdène. Une complexation non conventionnelle résulte
de l'encapsulation du macrocycle organique (CD) dans la cavité centrale du l’anneau inorganique
anionique (POM). Accroître la complexité du système en introduisant une troisième espèce, par
exemple un POM de type Keggin ou Dawson ou un cluster octaédrique, conduit à la formation
d'un assemblage supramoleculaire hybride par agencement hiérarchique des molécules
organiques et inorganiques. Cette structure nanoscopique multicouche a été caractérisée par DRX
sur monocristal démontrant ainsi la capacité du tore inorganique géant à développer une chimie
supramoléculaire hiérarchique grâce à la forte affinité des faces interne et externe duCD pour
les surfaces des polyoxométalates. De plus, les interactions et le comportement en solution ont
été étudiés par spectroscopie RMN multinucléaire qui montre des interactions spécifiques entre
différentes unités. La formation de cet assemblage hybride à trois composants suivant une
procédure en une seule étape, dans l'eau et à partir de conditions stoechiométriques, est discutée
en termes de forces motrices d’auto-organisation et reconnaissance moléculaire. Enfin, la
combinaison du concept de POM contenant des unités pentagonales mixtes à base de Mo/W avec
le système hybride hiérarchique a généré une architecture fascinante multifonctionnelle.
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