Die vorliegende Arbeit thematisiert Eisen(II)-Komplexe mit Spinübergangseigenschaften. Dafür wurden neue hexadentate Liganden auf Basis von N,N'-Bis(2,2'-bipyridin-6-ylmethyl)-2,2'-biphenylendiamin entwickelt. Die in Kapitel 3.1 vorgestellten Systeme variieren dabei in den jeweiligen Substituenten der 6,6‘-Positionen der Biphenyleinheit. Es wird der Einfluss dieser Gruppen auf die magnetischen Eigenschaften der resultierenden Komplexe gezeigt. Im darauffolgenden Kapitel 3.2 wird ein variiertes Ligandensystem vorgestellt, in welchem anstelle einfacher Substituenten Donorfunktionen eingeführt wurden, sodass ein symmetrischer dinuklearer Eisen(II)-Komplex zugänglich war. In diesem sind die beiden Spin Crossover (SCO) Zentren erstmalig durch eine Biphenyleinheit verbrückt. Die durchgeführten Untersuchungen geben Hinweise auf eine allostere Wechselwirkung. Weiterhin wurde der Ligand durch N-Methylierung in ein tertiäres Amin überführt und die entsprechenden Komplexe mit Fe(II), Co(II) und Zn(II) synthetisiert (Kapitel 3.3). Diese wurden strukturell und elektrochemisch untersucht und hinsichtlich ihrer Redoxeigenschaften und Magnetismus mit den Komplexen der sekundären Amine verglichen. Ebenfalls wurde das Grundgerüst des auf sekundären Aminen basierenden Liganden so variiert, dass der terminale Donor durch stickstoffhaltige Fünfringheterocyclen – anstelle von Pyridin – verkörpert wurde (Kapitel 3.4). So konnten Eisen(II)-SCO Komplexe erhalten werden, welche eine wesentlich niedrigere Übergangstemperatur aufwiesen und somit magnetische Untersuchungen im Festkörper sowie des Photomagnetismus ermöglichten. Schließlich wurden neue tridentate Amine (2-(6-R-Pyridin-2-yl)-1,10-phenanthrolin) und deren Eisen(II)-Komplexe synthetisiert (Kapitel 3.5). Für einige dieser Komplexe konnte bereits das Spin Crossover Verhalten in Lösung untersucht werden. / The present thesis addresses iron(II) complexes with spin transition properties. For this purpose new hexadentate ligands were developed on the basis of N,N’-bis(2,2’-bipyridine-6-ylmethyl)-2,2’-biphenylenediamine. The systems introduced in chapter 3.1 vary in respect to the substituents in the 6,6’-positions of the biphenyl unit. The influence of these varying moieties on the magnetic behavior of the resulting complexes is shown. In the following chapter 3.2 a tuned ligand system is introduced, in which the substituents are donor functions so that a symmetrical dinuclear iron(II) complex was feasible. In this the two Spin Crossover (SCO) centers are for the first time connected by a biphenyl core. The executed experiments give hints to an allosteric interaction in this dinuclear compound. Moreover the ligand was reacted by N-methylation yielding a tertiary amine and the corresponding complexes with Fe(II), Co(II) and Zn(II) were synthesized (chapter 3.3). Those were investigated structurally and electrochemically and were then compared with the complexes with secondary amines in respect to their redox and magnetic properties. The ligand motif based on secondary amines was also modified in a way that the terminal donor was represented by nitrogen based five-ring heterocycles instead of pyridine (chapter 3.4). So iron(II) SCO complexes were available which showed much lower thermal transition temperatures and thus magnetic investigations in the solid state as well as investigations on the photomagnetic properties became possible. Ultimately, novel tridentate amines (2-(6-R-pyridine-2-yl)-1,10-phenanthroline) and the corresponding iron(II) complexes were synthesized (chapter 3.5). For some of those complexes the spin transition could already be monitored in solution.

Les transitions de spin provoquent des changements de propriétés physiques des complexes de métaux du bloc d les subissant, notamment de leur structure et propriétés spectroscopiques. Ce mémoire porte sur la spectroscopie Raman de composés du fer(II) et du fer(III), pour lesquels on induit une transition de spin par variation de la température ou de la pression. Trois complexes de fer(II) de type FeN4(NCS)2 avec des comportements de transition de spin différents ont été étudiés : Fe(Phen)2(NCS)2 (Phen : 1,10-Phénanthroline), Fe(Btz)2(NCS)2 (Btz : 2,2’-bi-4,5-dihydrothiazine) et Fe(pyridine)4(NCS)2. Un décalage de l’ordre de 50 cm-1 est observable pour la fréquence d’étirement C-N du ligand thiocyanate des complexes FeN4(NCS)2, lors de la transition de spin induite par variation de la température ou de la pression. Il est possible d’utiliser cette variation de fréquence afin de tracer un profil de transition. Quatre complexes isomères de type FeL222(CN)2 (L222 : 2,13- diméthyl-6,9-dioxa-3,12,18-triazabicyclo[12.3.1]-octadéca-1(18),2,12,14,16-pentaène) ont également été étudiés. Un taux de décalage de l’ordre d’environ 0,03 cm-1/K est observé pour plusieurs bandes du complexe FeL222(CN)2. La bande à 1415 cm-1 disparaît à plus haute température au profit d’une bande à 1400 cm-1. Pour le complexe de chiralité R,R’, les bandes à 1008 cm-1 et 1140 cm-1 se déplacent vers des fréquences plus élevées à partir de 223 K. Les transitions de spin sont observées dans certains complexes de fer(III). Dans cette famille de composés, le complexe Fe(EtDTC)3 (EtDTC : N,N-diéthyldithiocarbamate) a été étudié . Aucun changement n’a été observé dans l’intensité des bandes d’étirement fer-soufre sur les spectres à température variable. Cependant, la bande Fe-S associée à la forme bas-spin à 530 cm-1 augmente en intensité au profit de la bande associée à la forme haut-spin à 350 cm-1 lors des mesures à haute pression, passant d’un rapport d’amplitude de 50% à pression ambiante à 80% à 21 kbar. Un dédoublement de la bande d’étirement C-N du ligand dithiocarbamate à 1495 cm-1 est également observé à des pressions supérieures à 5 kbar. Une comparaison des changements des fréquences de vibration de tous les complexes est effectuée. / AbstractSpin crossover processes lead to significant changes of molecular structures and spectroscopic properties measured for complexes of d-block transition metals. This thesis focuses on vibrational Raman spectroscopy of iron(II) and iron(III) compounds with spin transitions induced through temperature and pressure variations. Three iron(II) complexes of type FeN4(NCS)2 with different spin transition patterns have been studied: Fe(Phen)2(NCS)2 (Phen : 1,10-Phenanthroline), Fe(Btz)2(NCS)2 (Btz : 2,2’-bi-4,5- dihydrothiazine) and Fe(pyridine)4(NCS)2. A 50 cm-1 shift has been found for the C-N stretching frequency of the thiocyanate ligand in these compounds as a consequence of the spin transition induced by temperature or pressure. These frequency variations have been used to trace different transition profiles. Four different isomers of FeL222(CN)2 (L222 : [2,13-dimethyl-6,9-dioxa-3,12,18-triazabicyclo[12.3.1]-octadeca-1(18),2,12,14,16- pentaene]) type complexes have also been studied. A variation with temperature of approximately 0,03 cm-1/K has been observed for a few bands for the FeL222(CN)2 complex. A band at 1415 cm-1 decreases in intensity in favour of a band at 1400 cm-1 as temperature rises. The bands at 1008 cm-1 and 1140 cm-1 for the complex of R,R’ configuration shift to higher frequencies around 223 K. Spin transitions have also been investigated in some iron(III) complexes. In this family of compounds, the Fe(EtDTC)3 (EtDTC : N,N-diéthyldithiocarbamate) complex has been studied. No change has been observed in the intensity of the iron-sulphur stretching bands in spectra measured at variable temperature. However, at high pressure the low-spin Fe-S band at 530 cm-1 gains intensity compared to the high spin band at 350 cm-1. A splitting of the C-N stretching band of the dithiocarbamate ligand at 1495 cm-1 is observed at pressures above 5 kbar. A comparison of all changes in vibrational spectra is presented.

Cette thèse propose un regard nouveau sur l'étude du mécanisme de conversion de spin à l'aide de la diffraction des rayonnements X et neutronique. Cette technique est mise en œuvre de manière originale et permet d'obtenir des résultats inédits. Notre travail s'articule autour de l'exploration pionnière de cristaux à conversion de spin par la diffraction des neutrons, par l'obtention de films structuraux via de la diffraction X multi-températures et par l'étude de l'évolution de la qualité cristalline au fil des transitions. Les avancées de ce travail concernent aussi bien le niveau fondamental, apportant des informations de base sur le phénomène de conversion de spin, que le niveau expérimental, ouvrant de nouvelles voies d'investigation, en allant jusqu'à des éléments intéressants le domaine de l'application industrielle. Au niveau expérimental, l'étude multi-structurale proposée a permis, grâce à l'acquisition d'une quantité d'information considérable, l'élaboration d'un film de la conversion de spin, permettant de visualiser quasiment en continu toutes les modifications structurales induites par la conversion de spin. Les résultats fondamentaux qui en ont découlé concernent le mécanisme de commutation depuis l'échelle atomique jusqu'à celle de l'arrangement cristallin. L'étude de ce dernier a aussi été réalisée par diffraction neutronique qui permet la description des liaisons hydrogène dont le rôle, pourtant clef dans les matériaux moléculaires, est aujourd'hui peu étudié dans les complexes à conversion de spin. Enfin, la fatigabilité cristalline en relation avec le phénomène de conversion de spin a été abordée via un protocole expérimental pionnier mis en œuvre au laboratoire. Appliquée à l'évolution d'un complexe à conversion graduelle, cette approche expérimentale a mis en évidence un vieillissement du cristal au fil des cycles de conversion, et semble révéler un lien entre fatigabilité et structure macroscopique du système. / This thesis suggests a new perspective on the study of the mechanism of spin conversion using the diffraction of X-rays and neutrons. This technique is implemented in an original way and leads to unprecedented results. Our work focuses on the pioneer exploration of spin conversion complexes by neutron diffraction, by obtaining structural films via multi-temperature X-ray diffraction and by the study of the crystalline quality over spin crossovers. The progress of this work relates to both the fundamental level, providing crucial information on the phenomenon of spin conversion, and the experimental level, opening new avenues of investigation. At the experimental level, the multi-structural study has led, through the acquisition of a considerable quantity of data, to the production of a spin-crossover film, allowing to visualize almost continuously all structural changes induced by the spin conversion. Fundamental results concern the switching mechanism from the atomic to the the crystal packing scale. The study of the crystal packing was also carried out by neutron diffraction, which allows the description of hydrogen bonds whose role, yet key in molecular materials, is nowadays only rarely studied in the spin crossover complex field. Finally, the crystalline fatigability in connection with the phenomenon of spin crossover has been addressed through an experimental protocol implemented in the laboratory. Applied to the evolution of a gradual spin crossover complex, this experimental approach has highlighted the crystal aging over conversion cycles, and makes a link between fatigability and macroscopic structure of the system.

Lithiumeisen(II)-phosphat ist ein vielversprechendes und umweltfreundliches Kathodenmaterial für den Einsatz in Lithium-Ionen-Batterien (LIB), das eingehend im Hinblick auf seine thermodynamischen- und Oberflächeneigenschaften untersucht wurde. Zur Bestimmung der mittleren molaren Mischungsenthalpie von LiFePO4 und FePO4 wurde die Methode der isothermen Titrationskalorimetrie für die Untersuchung heterogener Stoffsysteme optimiert. Die Ergebnisse konnten mit elektrochemischen Gleichgewichtszellspannungsmessungen validiert werden. Ferner wurde die Oberflächenspannung von reinem LiFePO4 experimentell mit Hilfe der Kapillar-Aufstiegsmethode an Pulvern ermittelt. Ein weiterer Forschungsschwerpunkt stellte experimentelle Bestimmung der Wärmekapazität von phasenreinem orthorhombischen FePO4 dar. Des Weiteren wurde der Ablauf der hydrothermalen LiFePO4-Synthese ausgehend von Li3PO4 und Vivianit anhand von in-situ Messungen der elektrolytischen Leitfähigkeit und thermodynamischen Modellierungen aufgeklärt.

No description available.

This dissertation provides a survey of the available archaeological sources that have been discovered that help illuminate the history of the Northern Kingdom of Israel from King Omri (876 BCE) into the Assyrian Exile (721 BCE) of the Iron II a and b periods. This history is given in the Hebrew Scriptures as found in 1 Kings 16:16 to 2 Kings 17:6. To accomplish this research, several resources have been organized in a systematic approach. The artifacts and physical remains are examined in categories including: pottery, town planning, architecture, literacy and inscriptions, temples, gods, cult objects, metallurgy, weapons and warfare, weights and measures, farming, food preparation, music, jewelry, art, and burial. Photographs of several artifacts are included. With the background developed on the material culture, the next topic of importance to be considered is the archaeological sites and their relationship to this historic period. The relevant archaeological excavations and in-situ artifacts surveyed were found in areas of the former cultures including: Israel, Judah, Sinai, Edom, Moab, Amman, Lebanon, Syria, Aram, Assyria, Babylon and Persia. A vast number of these sited reveal information regarding the time period from King Omri, his son King Ahab and Ahab's wife, Queen Jezebel. There was interaction between Israel and Judah, and the kingdoms in Moab, Ammon, Lebanon, Aram, and Assyria. Eventually in 721 BCE many people were taken from the Israel into Exile and captivity by the Assyrians. The conclusion of this dissertation ties together the findings of the material sources with the historic events. The material sources have given considerable light on the history of the Northern kingdom as was given in the Hebrew Scriptures as is presented in this final section of the dissertation. / Religious Studies and Arabic / D.Litt. et Phil. (Biblical Studies)

This dissertation provides a survey of the available archaeological sources that have been discovered that help illuminate the history of the Northern Kingdom of Israel from King Omri (876 BCE) into the Assyrian Exile (721 BCE) of the Iron II a and b periods. This history is given in the Hebrew Scriptures as found in 1 Kings 16:16 to 2 Kings 17:6. To accomplish this research, several resources have been organized in a systematic approach. The artifacts and physical remains are examined in categories including: pottery, town planning, architecture, literacy and inscriptions, temples, gods, cult objects, metallurgy, weapons and warfare, weights and measures, farming, food preparation, music, jewelry, art, and burial. Photographs of several artifacts are included. With the background developed on the material culture, the next topic of importance to be considered is the archaeological sites and their relationship to this historic period. The relevant archaeological excavations and in-situ artifacts surveyed were found in areas of the former cultures including: Israel, Judah, Sinai, Edom, Moab, Amman, Lebanon, Syria, Aram, Assyria, Babylon and Persia. A vast number of these sited reveal information regarding the time period from King Omri, his son King Ahab and Ahab's wife, Queen Jezebel. There was interaction between Israel and Judah, and the kingdoms in Moab, Ammon, Lebanon, Aram, and Assyria. Eventually in 721 BCE many people were taken from the Israel into Exile and captivity by the Assyrians. The conclusion of this dissertation ties together the findings of the material sources with the historic events. The material sources have given considerable light on the history of the Northern kingdom as was given in the Hebrew Scriptures as is presented in this final section of the dissertation. / Religious Studies and Arabic / D.Litt. et Phil. (Biblical Studies)

The current thesis addresses the various facets of the chemistry of photocytotoxic iron complexes including their syntheses, characterization, evaluation of the anti-proliferative activities in various cancer cell lines upon photo-exposure, mechanism of cell death, the cellular uptake, localization inside cells, the interaction with double stranded DNA and their ability to induce DNA photocleavage. Chapter I presents a general introduction to cancer and the anticancer agents. It covers various procedures available for cancer treatment and different aspects of chemotherapy are discussed in details. The mechanism of action of several chemotherapeutic agents, the DNA cleavage pathways and the anticancer activity of bleomycins are delineated. Photo-chemotherapy or photodynamic therapy which has emerged as an alternative treatment modality is described. It also contains a brief description of ideal photosensitizers and the ones that are currently approved. The potential of transition metal complexes as photo-chemotherapeutic agents is discussed based on the recent literature reports on the prospective photocytotoxic metal complexes, the photo-release of cytotoxic molecules from metal complexes, the DNA cleavage activities and their cytotoxicities. The biochemistry of iron and its medical utility which prompted the development of iron based cytotoxins has been presented. The objective of the present investigation is also defined in this chapter. Chapter II describes the syntheses, characterization, evaluation of visible light induced cytotoxicity and interaction with DNA of a series of iron(II) bis-terpyridine complexes. Some interesting redox behaviour observed for two of the complexes has been described in details and rationalized from theoretical calculations. The DNA binding affinities of the complexes and their ability to induce DNA photocleavage in green light are discussed. The importance of this work lies in the remarkable photocytotoxic behaviour of the iron(II) complexes with visible light which was not reported earlier. Chapter III addresses the syntheses of a series of iron(III) catecholate complexes which upon irradiation with red light can initiate photoreactions to generate cytotoxic species and induce death in HeLa, HaCaT, MCF-7 and A549 cells. The mechanisms of cell death, effect of the complexes on the cell cycle under various conditions, the uptake inside cells and the cellular localization of the complexes are studied. The DNA binding affinities of the five complexes and their ability to induce DNA photocleavage in red light are also presented here. These are the first iron based complexes to show red light induced photocytotoxicity. Chapter IV addresses the drawbacks associated with the aforementioned iron(III) catecholates and their modification with a mitochondria targeting triphenylphosphonium unit. The synthesis, characterization, photocytotoxicities in HeLa, HaCaT, MCF-7 and A549, cell death mechanisms and cellular uptake and localization of four iron(III) complexes are discussed. Chapter V describes the syntheses, characterization and the biological activities of carbohydrate appended iron(III) complexes and their non-glucose analogues. The selective and faster internalization of the glyco-conjugated complexes in HeLa cells has been studied using various spectroscopic and microscopic techniques. The red light induced cytotoxicities of the complexes, their effect on the progression of the cell cycle with and without irradiation and the mechanisms of cell death are explored. DNA binding abilities and photocleavage of DNA are also discussed. Chapter VI presents the syntheses, characterization of a series of iron(III) complexes of a pyridoxal derivative and their salicyldehyde analogues for exploring their differential photocytotoxicity and cellular uptake in cancer cells compared to normal cells. The visible light induced cytotoxicities of the complexes in HeLa, HaCaT, MCF-7 A549 cells and HPL1D cells, their effect on the progression of the cell cycle in dark and light, the mechanisms of cell death and the localization of the complexes inside the cells are explored. The references have been compiled at the end of each chapter and given as superscripts in the text. The complexes presented in this thesis are indicated by bold-faced numbers. Crystallography data of the complexes that are structurally characterized by single crystal X-ray crystallography are given in CIF format in the enclosed CD (Appendix-I). Due acknowledgements have been made wherever the work described is based on the findings of other investigators. Any unintentional omission that might have happened due to oversight is regretted. INDEX WORDS: Iron complexes • Crystal structure • Red light induced cytotoxicity • Cellular imaging • DNA binding • DNA photocleavage.

Die vorliegende Arbeit thematisiert Eisen(II)-Komplexe mit Spinübergangseigenschaften. Dafür wurden neue hexadentate Liganden auf Basis von N,N'-Bis(2,2'-bipyridin-6-ylmethyl)-2,2'-biphenylendiamin entwickelt. Die in Kapitel 3.1 vorgestellten Systeme variieren dabei in den jeweiligen Substituenten der 6,6‘-Positionen der Biphenyleinheit. Es wird der Einfluss dieser Gruppen auf die magnetischen Eigenschaften der resultierenden Komplexe gezeigt. Im darauffolgenden Kapitel 3.2 wird ein variiertes Ligandensystem vorgestellt, in welchem anstelle einfacher Substituenten Donorfunktionen eingeführt wurden, sodass ein symmetrischer dinuklearer Eisen(II)-Komplex zugänglich war. In diesem sind die beiden Spin Crossover (SCO) Zentren erstmalig durch eine Biphenyleinheit verbrückt. Die durchgeführten Untersuchungen geben Hinweise auf eine allostere Wechselwirkung. Weiterhin wurde der Ligand durch N-Methylierung in ein tertiäres Amin überführt und die entsprechenden Komplexe mit Fe(II), Co(II) und Zn(II) synthetisiert (Kapitel 3.3). Diese wurden strukturell und elektrochemisch untersucht und hinsichtlich ihrer Redoxeigenschaften und Magnetismus mit den Komplexen der sekundären Amine verglichen. Ebenfalls wurde das Grundgerüst des auf sekundären Aminen basierenden Liganden so variiert, dass der terminale Donor durch stickstoffhaltige Fünfringheterocyclen – anstelle von Pyridin – verkörpert wurde (Kapitel 3.4). So konnten Eisen(II)-SCO Komplexe erhalten werden, welche eine wesentlich niedrigere Übergangstemperatur aufwiesen und somit magnetische Untersuchungen im Festkörper sowie des Photomagnetismus ermöglichten. Schließlich wurden neue tridentate Amine (2-(6-R-Pyridin-2-yl)-1,10-phenanthrolin) und deren Eisen(II)-Komplexe synthetisiert (Kapitel 3.5). Für einige dieser Komplexe konnte bereits das Spin Crossover Verhalten in Lösung untersucht werden. / The present thesis addresses iron(II) complexes with spin transition properties. For this purpose new hexadentate ligands were developed on the basis of N,N’-bis(2,2’-bipyridine-6-ylmethyl)-2,2’-biphenylenediamine. The systems introduced in chapter 3.1 vary in respect to the substituents in the 6,6’-positions of the biphenyl unit. The influence of these varying moieties on the magnetic behavior of the resulting complexes is shown. In the following chapter 3.2 a tuned ligand system is introduced, in which the substituents are donor functions so that a symmetrical dinuclear iron(II) complex was feasible. In this the two Spin Crossover (SCO) centers are for the first time connected by a biphenyl core. The executed experiments give hints to an allosteric interaction in this dinuclear compound. Moreover the ligand was reacted by N-methylation yielding a tertiary amine and the corresponding complexes with Fe(II), Co(II) and Zn(II) were synthesized (chapter 3.3). Those were investigated structurally and electrochemically and were then compared with the complexes with secondary amines in respect to their redox and magnetic properties. The ligand motif based on secondary amines was also modified in a way that the terminal donor was represented by nitrogen based five-ring heterocycles instead of pyridine (chapter 3.4). So iron(II) SCO complexes were available which showed much lower thermal transition temperatures and thus magnetic investigations in the solid state as well as investigations on the photomagnetic properties became possible. Ultimately, novel tridentate amines (2-(6-R-pyridine-2-yl)-1,10-phenanthroline) and the corresponding iron(II) complexes were synthesized (chapter 3.5). For some of those complexes the spin transition could already be monitored in solution.