Academic literature on the topic 'Paladium and Copper Complexes'

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>Triazenes are a class of compounds characterized by the presence of a diazoamino functional group (N=N N) showing remarkable ability to support the stereochemical requisites of a wide variety of metal transition complexes. They act as versatile ligands in coordination chemistry when deprotonated and have relevant biological and synthetic porperties. This work presents the synthesis and investigation of molecular and crystal structure of a new series of monotriazenes [3-(4-phenyldiazenyl)-1-(2-fluorophenyl)triazene (2b); 1-(2-chlorophenyl)-3-(4-phenyldiazenyl)triazeno (2c), 1-(2-bromophenyl)-3-(4-phenyldiazenyl)triazene (2d); 3-(4-phenyldiazenyl)-1-(2-iodophenyl) triazene (2e); 1,3-bis-(3-methoxy-4-methylbenzoate)triazene (2g)] and substituted 1,4-bis (phenyltriazenyl)butanes, C6H5N(H)=N-N(CH2)4-N=NN(H)C6H5, [1,4-bis(4-ethyl-benzoato triazenyl) butane (5a), 1,4-bis(2-fluorophenyltriazenyl)butane (5b), 1,4-bis(2-clorophenyltriazenyl)butane (5c), 1,4-bis(2-bromophenyltriazenyl)butane (5d), 1,4-bis(2-iodophenyltriazenyl)butane (5e), 1,4-bis(4-amidophenyltriazenyll)butane (5f)]. The insertion of groups on phenyl rings attached to the triazene chains makes the environment significantly more interesting coordination providing the supramolecular array through noncovalent intermolecular interactions and self-organizatinal units of primary molecule. The metal ions used for complexation are salts of Ni2+, Cu2+ and Pd2+ and they were chosen due to the attracting biological relevance, magnetic properties, catalytic yielding. Nine metal complexes unpublished were synthesized [trans-[PdII(C6H5NNC6H4NNNC6H4Cl)2(C5H5N)2] (3c) [(PdII (R1R2C6H3NNNC6H3R1R2)(PPh3)2Cl) DMSO] [R1 = 4-C(O)OCH3, R2 = 3-OCH3] (3g) [CuII (RC6H5NNN(CH2)4NNNC6H5R)]2 [R = C2H5C(O)O (6a), R = F (6b), R = NH2C(O) (6f)], [NiII (RC6H5NNN(CH2)4NNNC6H5R)]2 [R = F (7b) R = Cl (7c) R = Br (7d) R = NH2C(O) (7f)]. The synthesis and characterization of these compounds is justified by the exploration of the reactivity, the coordinative behavior and by the understanding of the interactions between different ligands and metal centers. The structural analysis of the synthesized compounds by X-ray diffraction on single crystal in the solid state were performed for characterization of interactions in the crystal. Thus, a thorough understanding of the relationship between the crystal structure and supramolecular organization is analyzed. Besides the structural analysis of compounds, elemental analysis CHN, infrared, nuclear magnetic resonance and ultraviolet-visible spectroscopies and mass spectrometry were also carried out for characterization. The physical chemical properties were investigated through thermogravimetric analysis and magnetic susceptibility.<br>Triazenos são importantes membros da família de compostos nitrogenados de cadeia aberta, caracterizados por conter o grupo funcional [N═N─N] e apresentam diferentes propriedades de coordenação a metais de transição. São compostos fracamente ácidos e quando desprotonados atuam como ótimos ligantes na química de coordenação apresentando grande importância sintética e biológica. Nessa tese, foi inicialmente desenvolvida a síntese de uma série inédita de compostos triazenos monocatenados [3-(4-fenildiazenil)-1-(2-fluorofenil)triazeno (2b); 1-(2-clorofenil)-3-(4-fenildiazenil)triazeno (2c); 1-(2-bromofenil)-3-(4-fenildiazenil)triazeno (2d); 3-(4-fenildiazenil)-1-(2-iodofenil)triazeno (2e); 1,3-bis(3-metoxi-4-metilbenzoato)triazeno (2g)] e de compostos triazenos biscatenados derivados do 1,4-bis(feniltriazenido)butano, C6H5N(H)N=N-(CH2)4-N=N-N(H)C6H5, [1,4-bis(etil-4-benzoatotriazenil) butano (5a); 1,4-bis(2-fluorofeniltriazenido)butano (5b); 1,4-bis(2-clorofeniltriazenido)butano (5c); 1,4-bis(2-bromofeniltriazenido)butano (5d); 1,4-bis(2-iodofeniltriazenido)butano (5e); 1,4-bis(4-amidofeniltriazenido)butano (5f)]. A inserção de grupamentos substituintes nos anéis fenila na cadeia triazenídica tornam o ambiente de coordenação significativamente mais interessante, propiciando o aumento da ocorrência de interações intermoleculares não covalentes e impondo a auto-organização de unidades moleculares primárias no estado sólido. Os metais escolhidos para complexação foram sais de Ni2+, Cu2+ e Pd2+ em virtude de atraírem atenção como objeto de estudos relacionados com medicina, propriedades magnéticas e catálise obtendo-se como resultados deste trabalho nove complexos metálicos inéditos [trans-[PdII(C6H5NNC6H4NNNC6H4Cl)2(C5H5N)2] (3c); [(PdII(R1R2C6H3NNNC6H3R1R2)(PPh3)2Cl)·DMSO] [R1 = 4-C(O)OCH3, R2 = 3-OCH3] (3g); [CuII(RC6H5NNN(CH2)4NNNC6H5R)]2 [R = C2H5C(O)O (6a); R = F (6b); R = NH2C(O) (6f)] ; [NiII(RC6H5NNN(CH2)4NNNC6H5R)]2 [R = F (7b); R = Cl (7c); R = Br (7d); R = NH2C(O) (7f)]. A síntese, e a caracterização desses novos compostos estão relacionadas à exploração da reatividade, ao comportamento coordenativo e a compreensão das interações entre os diferentes centros metálicos e os ligantes. Efetuou-se um estudo estrutural no estado sólido para a caracterização das interações presentes nas estruturas cristalinas dos compostos sintetizados e a ferramenta utilizada foi à difração de raios X em monocristal. Dessa forma aprofundou-se a compreensão da relação entre a estrutura cristalina e sua organização supramolecular. Além do método de difração de raios X de monocristal os compostos foram caracterizados por espectroscopia de infravermelho, espectroscopia de ressonância magnética nuclear, 1H e 13C, espectroscopia ultravioleta e visível, espectrometria de massas e análise elementar CHN. As propriedades físico-químicas foram investigadas através de análise termogravimétrica e susceptibilidade magnética.

Chapter One introduces molecular irnaging and the modalities available for oncological irnaging. The radioisotopes and imaging agents for Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT) are discussed together with the bifunctional chelator approach for radio labelling of biomolecules. Finally, the chemistry and radioisotopes of copper are described, and copper bis(thiosemicarbazonato) complexes introduced in the context of PET irnaging. Chapter Two describes the synthesis and characterisation of novel carboxylate- and maleirnide- functionalised bis(thiosemicarbazonates) and their conjugation to biologically active molecules. Radiolabelling of a chelator-bombesin conjugate demonstrated site-specific labelling at room temperature and preliminary in vitro and in vivo studies confirmed its potential as an imaging agent. Bioconjugation to a model protein and subsequent radiolabelling was also investigated. Chapter Three introduces molecular irnaging of hypoxia with a focus on CuATSM. An overview of the currently accepted mechanism of hypoxia selectivity is presented. The emphasis is placed on the relationship between oxygenation status, uptake and retention which display cell- and tumour- line dependency. Chapter Four presents the synthesis of copper bis(thiosemicarbazonates), radiolabelled either at the metal (64CU) or at the ligand e8F or 123n for mechanistic studies. The physicochemical characteristics of the copper complexes were measured and the complexes evaluated for their in vitro hypoxia selectivity. Chapter Five describes in vitro and in vivo studies of the orthogonally radiolabelled complexes, inclusive of control experiments with [64Cu]CuATS~, the radiolabelled proligand and [64CU]CU2+ salts. In vitro cellular assays, as well as in vivo biodistribution studies including dynamic PET and SPECT were performed. Stability studies contrasting the in vitro and in vivo behaviour were carried out. The collective data suggest that the currently proposed redox trapping mechanism might not provide a full understanding of the factors governing biodistribution and tumour uptake. Chapter Six contains full experimental details for the work described in this thesis.