CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior / Este trabalho tem como objetivo a sÃntese e caracterizaÃÃo de nano e micropartÃculas para liberaÃÃo de fÃrmaco para tratamento da malÃria. Microesferas de quitosana de alta massa molar (QTa) e goma do chichà (CH) foram sintetizadas por complexaÃÃo polieletrolÃtica e reticuladas com glutaraldeÃdo. Os diÃmetros das microesferas reticuladas e nÃo-reticuladas foram de 544  3 μm e 558  2 μm, respectivamente. As esferas reticuladas nÃo foram solÃveis em meio Ãcido (pH 1,2). Ensaios de intumescimento mostraram que as microesferas intumesciam mais em pH 1,2 do que em pH 7,4 e que as reticuladas possuÃam menor intumescimento do que as nÃo reticuladas. A liberaÃÃo sequenciada de cloroquina, a partir das microesferas, foi realizada por 2 h em pH 1,2 seguida por uma liberaÃÃo em pH 7,4. A microesfera reticulada liberou 64% da cloroquina em pH 1,2, com um total do fÃrmaco liberado de 92%. O perfil de liberaÃÃo da mesma amostra em pH 7,4 apresenta uma liberaÃÃo controlada do fÃrmaco por cerca de 50 h. NanopartÃculas de QT e CH foram produzidas utilizando como rotas de sÃntese a complexaÃÃo polieletrolÃtica e formaÃÃo de base de Schiff. Na formaÃÃo de complexos polieletrolÃticos parÃmetros como massa molar da quitosana, razÃo molar de carga (n+/n-), ordem de adiÃÃo e concentraÃÃo dos polieletrÃlitos influenciam no tamanho, potencial zeta, Ãndice de polidispersividade e estabilidade das nanopartÃculas em soluÃÃo. O potencial zeta das partÃculas com excesso de QT à positivo e quando se diminui a razÃo molar de carga (n+/n-) para 0,1 o potencial torna-se negativo devido o excesso de chichÃ. Os diÃmetros das nanopartÃculas variaram de 80 a 1200 nm dependendo da concentraÃÃo dos polieletrÃlitos e da quitosana utilizada. NanopartÃculas formadas por quitosana de baixa massa molar (QTb) possuem tamanho maior do que as formadas por quitosana de alta massa molar (QTa). Quando a razÃo de cargas (n+/n-) e a concentraÃÃo dos polieletrÃlitos diminuem o tamanho das nanopartÃculas tambÃm diminui. Na liberaÃÃo da cloroquina em matrizes de CH, QTa e QTb de razÃo 5 e 0,1 duraram cerca 15 dias liberando atà 99% do fÃrmaco, porÃm apenas a razÃo de cargas influenciou no perfil da liberaÃÃo. NanopartÃculas formadas via base de Schiff foram preparadas. A influÃncia de parÃmetros tais como: grau de oxidaÃÃo da goma do chichÃ, massa molar da quitosana, ordem de adiÃÃo e razÃo entre as massas dos polissacarÃdeos foram investigados em relaÃÃo ao tamanho, potencial zeta e estabilidade. O potencial zeta mostrou-se positivo para partÃculas com excesso de QT e negativo para partÃculas com excesso de CH. Os diÃmetros das partÃculas variaram de 30 a 450 nm, dependendo do grau de oxidaÃÃo do CH e da massa molar de QT. Para goma do chichà com menor grau de oxidaÃÃo nanopartÃculas de QTa apresentaram-se maiores do que as formadas por QTb, e para a goma com maior grau de oxidaÃÃo nanopartÃculas de QTb possuÃam maiores tamanhos do que as formadas por QTa. / The aim of this work was the synthesis and characterization of nano and microparticles for malaria drug delivery system. Chitosan microspheres of high molar mass (QTa) and chichà gum (CH) were synthesized by polyelectrolyte complexation and crosslinked with glutaraldehyde. The diameters of the microspheres crosslinked and non-crosslinked were 544  3 μm and 558  2 μm, respectively. The crosslinked beads were not soluble in acidic medium (pH 1.2). The swelling of microspheres was higher in pH 1.2 and that the crosslinked beads have less swelling than non-crosslinked. The sequential release of chloroquine from the microspheres was performed for 2 h followed by a release in pH 7.4. The crosslinked microsphere released 64% of chloroquine at pH 1.2, with a total of drug released of 92%. The release profile of the same sample at pH 7.4 provides a controlled release of the drug for about 50h. QT and CH nanoparticles were prepared using polyelectrolyte complexation and formation of Schiff base. In the formation of polyelectrolyte complex, parameters such as molecular weight of chitosan, the molar ratio of charge (n+/ n-), order of addition and concentration of the polyelectrolyte influence the size, zeta potential, polydispersity index and stability of the nanoparticles in solution. The zeta potential of particles in excess of QT was positive and when the charg molar ratio (n+/ n ) decreases to 0.1 the potential becomes negative due to the excess of CH. The nanoparticles diameters vary from 80 to 1,200 nm depending on the concentration of the polyelectrolyte and the chitosan used. Chitosan nanoparticles formed by a low molecular weight (QTb) were larger than those formed by chitosan of high molecular weight (QTa). The decrease of the charge ratio (n+/n-) and the polyelectrolyte concentrations lead to small size nanoparticle. The release of chloroquine in matrices of CH, QTa and QTb ratio ratio 5 and 0.1 lasted 15 days by releasing up to 99% of the drug, however only the ratio influenced the release profile. Nanoparticles formed by Schiff base reaction were produced. The influence of parameters such as degree of oxidation of CH, chitosan molar mass, addition and masses ration of polysaccharides on size, zeta potential and stability were investigated. The zeta-potential was positive for particles with an excess of QT and negative with excess CH. The particle diameters ranged from 30 to 450 nm, depending on the degree of oxidation of CH and the molar mass of QT. Particle formed with low oxidation of CH and high molar mass chitosan are bigger than those formed with low molar mass chitosan. A inverse behavior was observed when high oxidated CH was used.

Philosophiae Doctor - PhD / A novel monomer (N,N'-Bis-(1H-pyrrol-2-ylmethylene)-benzene-1,2-diamine-BPPD) was derived from the condensation reaction between o-phenylenediamine and a pyrrole derivative. The monomer was polymerized electrochemically to produce the new polymer material - polymerized(N,N'-Bis-(1H-pyrrol-2-ylmethylene)-benzene-1,2-diamine) PBPPD. This novel polymer material was deposited at the surface of a screen-printed carbon electrode, as a thin film, in the development of chemical sensors for the detection of polycyclic aromatic hydrocarbons (PAHs). The monomer material was characterized in terms of its optical (spectroscopy) and thermal properties. The polymer material was characterized in terms of its surface morphology and its redox electrochemistry. Fourier transform infrared spectroscopy (FTIR) was used to confirm the azomethine bond formation during the condensation reaction of an aldehyde and primary amine derivative. / 2020-08-31

Les précurseurs de ligands base de Schiff électro-donneurs et électro-accepteurs R-ONOH₂ sont préparés par réaction de monocondensation entre les β-dicétones appropriées et respectivement le 1,2- et le 1,2-4-nitro-aminophénol. Ils existent exclusivement sous leurs formes tautomériques céto-énamine en solution et à l'état solide. Dans les complexes correspondants de NiII et de CuII, le métal adopte une géométrie plan carré et est coordiné par les atomes d'azote et d'oxygène du ligand dianionique tridentate et par l'azote du coligand pyridine. L'hyperpolarisabilité quadratique, déterminée par la technique DHL est très élevée. La substitution de la pyridine par la 4,4'-bipyridine conduit systématiquement aux complexes dimériques correspondants. Un composé similaire comportant l'espaceur bis(4-pyridyle)acétylène est formé après réaction de couplage croisé de Sonogashira. Cette même réaction de couplage croisé entre les blocs de construction électrodonneurs et électro-accepteur permettent de préparer le système «push-pull» D-π-A désiré. Les réponses ONL du second ordre des complexes contenant le ligand électro-actif methylène-pyrane peuvent être modulées par bi- (R = An) et tétra- (R = Fc) oxydation réversible avec formation/rupture d'une liaison C-C, constituant ainsi un nouvel exemple de commutateur ONL-2 réversible. / Electron donating and electron withdrawing ligand precursors R-ONOH₂ were prepared by monocondensation reaction of the appropriate β-diketones and 1,2- and 1,2-4-nitro-aminophenol, respectively. They do exclusively exist as their enaminone tautomeric form both in solid-state and in solution phase. In their corresponding Schiff base complexes of NiII and CuII, the central metal is tetracoordinated in a square-planar environment. The coordination sphere is formed by the nitrogen and oxygen atoms of the dianionic tridentate ligand and the fourth coordination site is occupied by the nitrogen atom of the pyridine co-ligand. The derivative exhibited a high quadratic hyperpolarizability (β1.91) determined by the HLS technique. Substitution of 4,4’-bipyridine for pyridine invariably leads to the formation of the respective dimers [(R-ONO)MII(4,4’-bipy)MII(ONO-R)]. A similar compound having the bis(4-pyridyle)acetylene as spacer was formed upon cross-coupling Sonogashira reaction with ethynylpyridine chlorhydrate. The same cross-coupling reaction carried out between the electron releasing and electron withdrawing building blocks, respectively, allowed the preparation of the expected «push-pull» D-π-A system. The second-order NLO responses of compounds bearing a redox active methylenepyran ligand can be modulated upon reversible bi- (R = An) and tetra- (R = Fc) oxydation involving C-C bond formation/breaking reactions, thus forming a new class of NLO molecular switches.

Self-assembly processes were used to construct supramolecular architectures based on metal-ligand interactions. The structures formed strongly depend on the used metal ion, the ligand type, the chosen counter ion and solvent as well as on the experimental conditions. The focus of the studies was the design of multifunctional N-donor ligands and the characterization of their complexing and structural properties. This work was divided into three distinct main parts: The bis(2-pyridylimine), the bis(2-hydroxyaryl) imine and the tripodal imine / amine ligand approach. In the first part a series of bis(2-pyridylimine) derivatives having different linking elements were employed as building blocks for novel supramolecular architectures. Reaction of individual d-block metal salts with these ligands has led to the isolation of coordination polymers, a metallamacrocycle, double-stranded helicates, triple-stranded helicates as well as of circular meso-helicates. The nature of the spacer in the Schiff base ligands, the noncovalent weak interactions, such as hydrogen bond, face-to-face π-π and edge-to-face CH-π interactions, are all important factors influencing the architecture of the final products. Topological control of the assembly process of the hexanuclear meso-helicates is clearly associated with the bidentate coordination of the sulfate anion which directs the formation of a double- rather than a triple-stranded helicate around the octahedrally coordinated Cu(II). Surprisingly, the variation of the linker function in the ligands, which significantly changes the linking angle of the pyridylimine strands, has only a little influence of the resulting structure. Also the use of a mixture of ligands does not influence the meso-helicate topology; the result is the symmetrically mixed meso-helicate. The new iron(II) triple helicate [Fe2(L5)3](PF6)4 14 {L5 = bis[4-(2-pyridylmethyleneimino)phenyl]-1,1-cyclohexane} in its chloride form binds strongly to DNA as confirmed by induced circular dichroism signals in both the metal-to-ligand charge transfer (MLCT) and in-ligand bands of the helicate. The induced CD spectrum gives some evidence that [Fe2(L5)3]4+ interacts with the DNA in a single binding mode, which is consistent with major groove binding. The cytotoxicity of the new iron(II) triple helicate 14 was evaluated on human lung cancer A549 cells and compared with that of cisplatin and that of the previously reported iron(II) triple helicate [Fe2(L1)3]4+{L1 = bis[4-(2-pyridylmethyleneimino)phenyl]methane}. The first results show some distinguishing features for 14 obviously caused by the existing structural differences of the complexes. In the second part of the thesis, novel uranyl complexes of the bis(2-hydroxyaryl) imine ligands have been synthesized and characterized. 1D coordination polymers and mononuclear structures were formed. In all complexes a distorted hexagonal bipyramidal coordination geometry around the uranyl centre is observed. The imine nitrogen atoms of the ligands do not bind to the metal centre but interact strongly with the hydroxy group via H-bonding. DFT calculations made with L8 ( α,α’-Bis(salicylimino)-m-xylene) are in good agreement with the X-ray crystal structure data. Liquid-liquid extraction studies involving selected ligands and Eu(III) or U(VI) indicate remarkably high selectivity for U(VI) over Eu(III) at weak acidic pH conditions. We believe that the study made opens up new possibilities for uranyl ion extraction which could be interesting in view of the treatment of nuclear waste. In the third part of the thesis, a series of multifunctional tripodal ligands with different N-donor centres were used for U(VI) and lanthanide, Nd(III), Eu(III) and Yb(III), binding and extraction. Reaction of these metal ions with selected tripodal ligands afforded complexes which were characterized by ESI mass spectroscopy. The complex composition was found to be 1:1 in all cases. The extraction behaviour of the tripodal ligands towards Eu(III) and U(VI) was studied both in the absence and presence of octanoic acid as co-ligand using the extraction system Eu(NO3)3 or UO2(NO3)2–buffer–H2O/ ligand–CHCl3. These separation systems show a remarkably high selectivity for U(VI) over Eu(III). It is interesting to note that the addition of the octanoic acid to the extraction system leads to high synergistic effects. A series of Eu(III) extraction experiments were done to clarify the composition of the extracted complexes. The results clearly point to the formation of various species with changing composition.

The reaction of di­chloro­dimethyl­silane with a polydentate Schiff base ligand derived from pyridoxal and 2-ethano­lamine yielded the macrocyclic silicon compound (8E,22E)-4,4,12,18,18,26-hexa­methyl-3,5,17,19-tetra­oxa-8,13,22,27-tetra­aza-4,18-disilatri­cyclo­[22.4.0.010,15]octa­cosa-1(24),8,10,12,14,22,25,27-octa­ene-11,25-diol, C24H36N4O6Si2. The asymmetric unit contains the half macrocycle with an intra­molecular O—H⋯N hydrogen bond between the imine nitro­gen atom and a neighbouring oxygen atom. The crystal structure is dominated by C—H⋯O and C—H⋯π inter­actions, which form a high ordered mol­ecular network.

La tagatose-1,6-biphosphate aldolase de Streptococcus pyogenes est une aldolase qui fait preuve d'un remarquable manque de spécificité vis à vis de ses substrats. En effet, elle catalyse le clivage réversible du tagatose-1,6-bisphosphate (TBP), mais également du fructose-1,6-bisphosphate (FBP), du sorbose-1,6-bisphosphate et du psicose-1,6-bisphosphate, quatre stéréoisomères, en dihydroxyacétone phosphate (DHAP) et en glycéraldéhyde-3-phosphate (G3P). Aldolase de classe I, qui donc catalyse sa réaction en formant un intermédiaire covalent obligatoire, ou base de Schiff, avec son susbtrat, la TBP aldolase de S. pyogenes partage 14 % d’identité avec l’enzyme modèle de cette famille, la FBP aldolase de muscle de mammifère. Bien que le mécanime catalytique de la FBP aldolase des mammifères ait été examiné en détails et qu’il soit approprié d’en tirer des renseignements quant à celui de la TBP aldolase, le manque singulier de stéréospécificité de cette dernière tant dans le sens du clivage que celui de la condensation n’est toujours pas éclairci. Afin de mettre à jour les caractéristiques du mécanisme enzymatique, une étude structurale de la TBP aldolase de S. pyogenes, un pathogène humain extrêmement versatile, a été entreprise. Elle a permis la résolution des structures de l’enzyme native et mutée, en complexe avec des subtrats et des inhibiteurs compétitifs, à des résolutions comprises entre 1.8 Å et 2.5 Å. Le trempage des cristaux de TBP aldolase native et mutante dans une solution saturante de FBP ou TBP a en outre permis de piéger un authentique intermédiaire covalent lié à la Lys205, la lysine catalytique. La determination des profils pH de la TBP aldolase native et mutée, entreprise afin d'évaluer l’influence du pH sur la réaction de clivage du FBP et TBP et ìdentifier le(s) résidu(s) impliqué(s), en conjonction avec les données structurales apportées par la cristallographie, ont permis d’identifier sans équivoque Glu163 comme résidu responsable du clivage. En effet, le mode de liaison sensiblement différent des ligands utilisés selon la stéréochimie en leur C3 et C4 permet à Glu163, équivalent à Glu187 dans la FBP aldolase de classe I, d’abstraire le proton sur l’hydroxyle du C4 et ainsi d’amorcer le clivage du lien C3-C4. L’étude du mécanimse inverse, celui de la condensation, grâce par exemple à la structure de l’enzyme native en complexe avec ses substrats à trois carbones le DHAP et le G3P, a en outre permis d’identifier un isomérisme du substrat G3P comme possible cause de la synthèse des isomères en C4 par cette enzyme. Ce résultat, ainsi que la decouverte d’un possible isomérisme cis-trans autour du lien C2-C3 de la base de Schiff formée avec le DHAP, identifié précedemment, permet de cerner presque complètement les particularités du mécanisme de cette enzyme et d’expliquer comment elle est capable de synthétiser les quatres stéréoisomères 3(S/R), 4(S/R). De plus, la résolution de ces structures a permis de mettre en évidence trois régions très mobiles de la protéine, ce qui pourrait être relié au rôle postulé de son isozyme chez S. pyogenes dans la régulation de l’expression génétique et de la virulence de la bactérie. Enfin, la résolution de la structure du mutant Lys229→Met de la FBP aldolase de muscle en complexe avec la forme cyclique du FBP, de même que des études cristallographiques sur le mutant équivalent Lys205→Met de la TBP aldolase de S. pyogenes et des expériences de calorimétrie ont permis d’identifier deux résidus particuliers, Ala31 et Asp33 chez la FBP aldolase, comme possible cause de la discrimination de cette enzyme contre les substrats 3(R) et 4(S), et ce par encombrement stérique des substrats cycliques. La cristallographie par rayons X et la cinétique enzymatique ont ainsi permis d'avancer dans l'élucidation du mécanisme et des propriétés structurales de cette enzyme aux caractéristiques particulières. / Tagatose-1,6-bisphosphate aldolase from Streptococcus pyogenes is a class I aldolase that shows a lack of stereospecificity that is rare in enzymes in general, and in aldolases in particular. This aldolase catalyzes the reversible cleavage of tagatose-1,6-bisphosphate (TBP), fructose-1,6-bisphosphate (FBP), sorbose-1,6-bisphosphate and psicose-1,6-bisphosphate, four stereoisomers, in dihydroxyacetone phosphate (DHAP) and glyceraldehyde-3-phosphate (G3P). A class I aldolase, the aldolase TBP S. pyogenes shares 14 % identity with the model enzyme of this family, mammalian FBP aldolase. Although the catalytic mechanism of the class I FBP aldolase has been examined in detail and it is appropriate to infer information as to the class I TBP aldolase, the singular lack of specificity of the latter enzyme both in the direction of cleavage and condensation is still not elucidated. To better comprehend the characteristics of the enzymatic mechanism, a structural study of the TBP aldolase of S. pyogenes, an extremely versatile human pathogen, has been undertaken. It has allowed the resolution of high resolution structures of the native and mutated enzyme in complex with subtrates and competitive inhibitors. These same structures allowed us to gain information as to the active site of the enzyme in general and the catalytic residues in particular. TBP aldolase native and mutated soaked in a saturated solution of FBP or TBP also trapped an iminium intermediate covalenty bound to Lys205, the Schiff base-forming lysine. The determination of the pH profiles of the native and mutated enzyme, carried out to assess the influence of pH on FBP and TBP cleavage and identify the residue(s) involved, in conjunction with the structural data provided by crystallography, identified unequivocally Glu163, corresponding to Glu187 in FBP aldolase, as the residue responsible for substrate cleavage. The substantially different binding mode of the ligands, according to the stereochemistry of their C3 and C4 carbons, indeed allows Glu163 to abstract the proton in C3-OH and thus initiate C3-C4 bond cleavage. The study of the inverse mechanism, the condensation one, using for instance the crystallographic structure of native TBP aldolase in complex with DHAP and G3P, its three carbons substrates, has led us to believe that a possible isomerism of the G3P substrate was the reason for the synthesis of both C4 isomers by this enzyme. This result, as well as the discovery of a possible cis-trans isomerism around the C2-C3 bond of the Schiff base formed with DHAP, identified previously, almost completely elucidated the features of this enzyme`s mechanism. In addition, these structures have highlighted three highly mobile regions of the protein, which may be related to the role of its isozyme in the regulation of gene expression and virulence in S. pyogenes. Lastly, the resolution of the structure of the FBP aldolase mutant Lys229 → Met in complex with the cyclic form of FBP, as well as crystallographic studies of the corresponding mutant in TBP aldolase, Lys205→Met and ITC experiments, allowed the identification of two particular residues, Ala31 and Asp33 in FBP aldolase, as responsible for this enzyme discrimination against 3(R) 4(S) substrates, by steric hindrance of the cyclic substrates. X-ray crystallography, enzyme kinetics and isothermal calorimetry thus enabled advances in the elucidation of the mechanism and structural properties of this enzyme with singular characteristics.

In der vorliegenden Arbeit wird die Synthese und Charakterisierung von chiralen prolylfunktionalisierten Farbstoffen vorgestellt. Als chromophore Schlüsselverbindungen wurden Nitroaniline aber auch größere push-pull pi-Systeme wie Schiffsche Basen, Azofarbstoffe und Merocyanine gewählt. Im Fokus dieser Arbeit stehen dabei deren solvatochrome Eigenschaften, pH-Sensitivität sowie mögliche Wechselwirkung mit Biomolekülen und verschiedenen An- und Kationen. Zusätzlich erfolgten Umsetzungen ausgewählter prolylfunktionalisierter chromophorer Bausteine zu Estern und Amiden. Der Einfluss des Prolylbausteins auf das im Festkörper ausgebildete Wasserstoffbrückenbindungsmusters wurde über Einkristallröntgenstrukturanalysen untersucht und nach der Graph Set Methode von Etter klassifiziert. Neben der Einkristallröntgenstrukturanalyse erfolgte die weitere Untersuchung der Festkörpereigenschaften mit Hilfe von UV/Vis- sowie NMR-spektroskopischen Methoden. Das solvatochrome Verhalten der prolylfunktionalisierten Verbindungen wurde mittels multipler linearer Regressionsanalyse gemäß der LSER- (linear solvation energy relationship) Beziehung nach den Ansätzen von Kamlet-Taft und Catalán beschrieben und vergleichend interpretiert.

The present thesis deals with different aspects of the chemistry of oxovanadium(IV) complexes, their interaction with double stranded DNA, photo-induced DNA cleavage, photo-enhanced cytotoxicity in visible light and red light and localisation and cellular uptake to understand the mechanism of cell death. Chapter I presents a general introduction on potential of transition metal complexes as photochemotherapeutic agents. A brief introduction about Photodynamic Therapy (PDT) as a new alternative to chemotherapy for treating cancer has been made. Various modes of interaction of small molecules with duplex DNA are described. Recent reports on metal-based photocytotoxicity, photo-induced DNA cleavage activity and cellular localization are presented in detail. Objective of the present investigation is also dealt in this Chapter. Chapter II of the thesis deals with the synthesis, characterization, DNA binding and photo-induced DNA cleavage activity of ternary oxovanadium(IV) complexes of ONO-donor 2-(2-hydroxybenzylideneamino)phenol (salamp) and phenanthroline bases to explore the photo-induced DNA cleavage activity in UV-A light of 365 nm and photocytotoxicity in visible light. Chapter III deals with the photo-induced DNA cleavage and photocytotoxicity of ternary oxovanadium(IV) complexes containing ONN-donor N-2-pyridylmethylidine-2-hydroxyphenylamine (Hpyamp) Schiff bases and phenanthroline bases. The objective of this work is to investigate the photo-induced DNA cleavage activity in near-IR light. Photocytotoxicity and cell cycle arrest have been studied in HeLa cancer cells. Chapter IV deals serendipitous discovery of planar triazinuim cationic species by vanadyl-assisted novel ring cyclization reaction. The compounds are synthesised, characterized and their DNA binding and anaerobic photoinduced DNA cleavage activity are presented. The importance of the thiazole moiety in the triazinuim species in cellular uptake has been investigated. Photocytotoxicity, localization and cell death mechanism have been studied in HeLa and MCF-7 cells. Chapter V describes the synthesis, characterization, DNA binding, photo-induced DNA cleavage activity and photocytotoxicity of oxovanadium(IV) complexes containing 2-(1H-benzimidazol-2-yl)-N-(pyridin-2-ylmethylene)ethaneamine (Hpy-aebmz) and curcumin as photosensitizer. The effect of conjugating naphthalimide on Hpy-aebmz on photoinduced DNA cleavage and photocytotoxicity has been studied. Cellular uptake, localization and mechanism of cell death induced by complexes have been investigated. Chapter VI presents ternary oxovanadium(IV) complexes having, 2-((1H-benzimidazol-2-yl)methylimino-methyl)phenol (Hsal-ambmz) and phenanthroline bases. The complexes were synthesized, characterized and their DNA binding property studied. Photo-induced DNA cleavage activity and photocytotoxicity in red light has been discussed. Anthracene has been conjugated to a tridentate ligand to investigate cellular uptake, localization and cell death mechanism. Mitochondria targeting property of the complexes having dipeptide has been studied and compared with clinically used drug Photofrin®. The references have been compiled at the end of each chapter and indicated as superscript numbers in the text. The complexes presented in this thesis are represented by bold-faced numbers. Crystallographic data of the complexes, characterized structurally 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 or mistake is regretted.

In der vorliegenden Arbeit wird die Synthese und Charakterisierung von chiralen prolylfunktionalisierten Farbstoffen vorgestellt. Als chromophore Schlüsselverbindungen wurden Nitroaniline aber auch größere push-pull pi-Systeme wie Schiffsche Basen, Azofarbstoffe und Merocyanine gewählt. Im Fokus dieser Arbeit stehen dabei deren solvatochrome Eigenschaften, pH-Sensitivität sowie mögliche Wechselwirkung mit Biomolekülen und verschiedenen An- und Kationen. Zusätzlich erfolgten Umsetzungen ausgewählter prolylfunktionalisierter chromophorer Bausteine zu Estern und Amiden. Der Einfluss des Prolylbausteins auf das im Festkörper ausgebildete Wasserstoffbrückenbindungsmusters wurde über Einkristallröntgenstrukturanalysen untersucht und nach der Graph Set Methode von Etter klassifiziert. Neben der Einkristallröntgenstrukturanalyse erfolgte die weitere Untersuchung der Festkörpereigenschaften mit Hilfe von UV/Vis- sowie NMR-spektroskopischen Methoden. Das solvatochrome Verhalten der prolylfunktionalisierten Verbindungen wurde mittels multipler linearer Regressionsanalyse gemäß der LSER- (linear solvation energy relationship) Beziehung nach den Ansätzen von Kamlet-Taft und Catalán beschrieben und vergleichend interpretiert.