Investigação estrutural e atividade tuberculostática de complexos mononucleares e binucleares de paládio (II)
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2010-02-23
Autores
Silva, Cristiana da [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
O presente trabalho consistiu na síntese, caracterização estrutural e verificação das atividades tuberculostáticas de quatro novos complexos de paládio(II). Os novos complexos caracterizados foram: [PdCl2(HPz)(PPh3)](1), [Pd2(µ-N3)(µ-Pz)Cl2(PPh3)2](2), [Pd2(µ-N3)(µ- Pz)(N3)2(PPh3)2](3) e [Pd(µ-Pz)(N3)(PPh3)]2(4) sendo suas estruturas propostas com base em medidas de análise elementar, espectroscopia vibracional na região do infravermelho, ressonância magnética nuclear de 1 H, 13 C{1 H} e 31 P{1 H}e por análise térmica. A partir da reação entre o precursor [PdCl2(CH3CN)2] com os ligantes pirazol(HPz) e trifenilfosfina(PPh3), originou-se o complexo mononuclear [PdCl2(HPz)(PPh3)](1). As reações entre o complexo mononuclear 1 e NaN3, sob distintas condições, levou á formação dos complexos binucleares 2 e 4. E da reação entre o complexo 2 com azida de sódio originou-se o complexo binuclear 3. A difração de raios X de monocristal comprovou co-cristalização dos compostos 2 e 3, na mesma célula unitária, na proporção de 36,3% e 63,7%, respectivamente, confirmando as proposições estruturais sugeridas pela espectroscopia na região do IV. Ambas são espécies binucleares, com os dois átomos de paládio unidos por um grupo pirazolato exobidentado e um grupo azida end-on, resultando em um anel de 5 membros, [Pd(µ-N3)(µ-Pz)Pd]. Os dois complexos apresentam geometria de coordenação quadrática-planar distorcida ao redor de cada átomo de paládio, com os átomos de fósforo de cada molécula de PPh3 encontrando-se trans-posicionados em relação ao átomo de nitrogênio pertencente ao grupo azida end-on. Constatou-se ainda que as distâncias de ligação Pd-P e Pd-Cl são próximas aquelas de outros complexos binucleares encontrados na literatura. A espectroscopia vibracional na região do infravermelho possibilitou confirmar a presença...
This study presents the synthesis, structural characterization and verification of tuberculostatic activity of four new complexes of palladium (II). The new complexes: [PdCl2(HPz)(PPh3)](1), [Pd2(µ-N3)(µ-Pz)Cl2(PPh3)2](2),[Pd2(µ-N3)(µ-Pz)(N3)2(PPh3)2] (3) and [Pd(µ-Pz)(N3)(PPh3)]2(4) were characterized and their structures proposed on measurements of elemental analysis, infrared vibrational spectroscopy , 1 H, 13 C{1 H} and 31 P{1 H} nuclear magnetic resonance and thermal analysis. From the reaction of the precursor [PdCl2(CH3CN)2] with the ligands pyrazol (HPz) and triphenylphosphine (PPh3), it was obtained the mononuclear complex [PdCl2 (HPz)(PPh3)](1). The reactions between the mononuclear complex 1 and NaN3, under different conditions led to the formation of binuclear complexes 2 and 4. The reaction of complex 2 and sodium azide originated the binuclear complex 3. The single cristal X ray diffraction has proved co-crystallization of the compounds 2 and 3 in the same unit cell, confirming the structural propositions suggested by IR spectroscopy. Both species are binuclear with two palladium atoms joined by pyrazolato exobidentate and an azide end-on group, resulting in a five membered ring, [Pd(µ-N3)(µ- Pz)Pd]. The two complexes have a distorted square-planar coordination geometry around each palladium atom with the phosphorus atoms of each PPh3 molecule lying trans to the nitrogen atom belonging to the end-on azide. It was further observed that the Pd-P and Pd-Cl bond distances are close to those found in binuclear complexes described in the literature. The vibrational spectroscopy in the infrared region has confirmed the presence of ligands and their modes of coordination to the metallic center. In complex 1 the coordination of pyrazole was monodentate and the exobidentate coordination was observed in binuclear complexes 2, 3 and 4. Regarding... (Complete abstract click electronic access below)
This study presents the synthesis, structural characterization and verification of tuberculostatic activity of four new complexes of palladium (II). The new complexes: [PdCl2(HPz)(PPh3)](1), [Pd2(µ-N3)(µ-Pz)Cl2(PPh3)2](2),[Pd2(µ-N3)(µ-Pz)(N3)2(PPh3)2] (3) and [Pd(µ-Pz)(N3)(PPh3)]2(4) were characterized and their structures proposed on measurements of elemental analysis, infrared vibrational spectroscopy , 1 H, 13 C{1 H} and 31 P{1 H} nuclear magnetic resonance and thermal analysis. From the reaction of the precursor [PdCl2(CH3CN)2] with the ligands pyrazol (HPz) and triphenylphosphine (PPh3), it was obtained the mononuclear complex [PdCl2 (HPz)(PPh3)](1). The reactions between the mononuclear complex 1 and NaN3, under different conditions led to the formation of binuclear complexes 2 and 4. The reaction of complex 2 and sodium azide originated the binuclear complex 3. The single cristal X ray diffraction has proved co-crystallization of the compounds 2 and 3 in the same unit cell, confirming the structural propositions suggested by IR spectroscopy. Both species are binuclear with two palladium atoms joined by pyrazolato exobidentate and an azide end-on group, resulting in a five membered ring, [Pd(µ-N3)(µ- Pz)Pd]. The two complexes have a distorted square-planar coordination geometry around each palladium atom with the phosphorus atoms of each PPh3 molecule lying trans to the nitrogen atom belonging to the end-on azide. It was further observed that the Pd-P and Pd-Cl bond distances are close to those found in binuclear complexes described in the literature. The vibrational spectroscopy in the infrared region has confirmed the presence of ligands and their modes of coordination to the metallic center. In complex 1 the coordination of pyrazole was monodentate and the exobidentate coordination was observed in binuclear complexes 2, 3 and 4. Regarding... (Complete abstract click electronic access below)
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Química inorgânica, Inorganic chemistry
Como citar
SILVA, Cristiana da. Investigação estrutural e atividade tuberculostática de complexos mononucleares e binucleares de paládio (II). 2010. 97 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Química, 2010.