Síntese, caracterização e investigação da atividade biológica de complexos de cobre e paládio contendo ligantes N,S doadores
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Data
2009-02-17
Autores
Arantes, Francisco Carlos Caliari [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Este trabalho envolve a síntese e caracterização espectroscópica de compostos mononucleares de Pd(II) obtidos a partir da interação entre o precursor [PdCl2(MeCN)2], tiouréias N-substituídas (metu = N-metiltiouréia; ftu = N-feniltiouréia) e trifenilfosfina (PPh3), na presença dos íons SCN- e Br - . A reação entre [PdCl2(MeCN)2], tiouréias N-substituídas e a trifenilfosfina, na razão molar de 1:1:1, respectivamente, forma os complexos [PdCl2(Rtu)(PPh3)] (Rtu = metu, ftu). Os complexos [PdX2(PPh3)(Rtu)] (Rtu = metu, ftu; X- = SCN, Br) foram preparados a partir da interação entre o respectivo cloro-complexo e sais KX, razão molar de 1:2, respectivamente. A coordenação das tiouréias N-substituídas pelo átomo de enxofre na série [PdX2(PPh3)(Rtu)] (X- = Cl, SCN, Br) foi evidenciada pela espectroscopia no IV pelo deslocamento da banda C-NHR para freqüências mais altas em relação a do ligante livre, indicando o fortalecimento da ligação CN. Os espectros de RMN também mostram a coordenação via átomo de S pelo deslocamento do sinal de 13 C do grupo tionila para regiões de campo alto quando comparado ao do ligante Rtu, evidenciando o enfraquecimento da ligação CS após a coordenação. Já a presença da trifenilfosfina foi sugerida pelo aparecimento das suas bandas no IV típicas em 1098 cm-1 (CH), 693 cm-1 (anel) e 520 cm-1 (modo y). As curvas TG-DTA obtidas mostram que os complexos se decompõem em Pd0 sem formar uma fase estável de sulfeto metálico. A reação entre a N,N´-difeniltiouréia e íons Cu(II) também foi investigada neste trabalho. O composto obtido de fórmula [CuCl(dftu)2]n foi caracterizado pelas espectroscopias no IV e de RMN de 1 H e 13 C{1 H}. A atividade inibitória dos compostos dftu e [CuCl(dftu)2]n frente ao crescimento dos fungos Candida albicans, Candida krusei, Candida parapsilosis e Candida neoformans também foi avaliada.
This work deals with the syntheses, spectroscopic characterization of Pd(II) mononuclear compounds obtained from the interaction among [PdCl2(MeCN)2] precursor, N-substituted thioureas (metu = N-methylthiourea; ftu = N-phenylthiourea) and triphenylphosphine (PPh3), in the presence of SCN- e Br - ions. The reaction among [PdCl2(MeCN)2], N-substituted thioureas and triphenylphosphine, in the molar ratio 1:1:1, respectively, yield the complexes [PdCl2(PPh3)(Rtu)] (Rtu = metu, ftu). The compounds [PdX2(Rtu)(PPh3)] (Rtu = metu, ftu; X- = SCN, Br) were prepared from the interaction between the appropriate chloro-complex and KX salts, in molar ratio 1:2, respectively. The coordination of N-substituted thioureas through sulfur atom in the serie [PdX2(PPh3) (Rtu)] (X- = Cl, SCN, Br) was inferred by IR spectroscopy by the shift of C-NHR band to higher frequencies than those of the free ligand, indicating an increasing in the CS bond strenght. NMR spectra also showed the S-coordination by the upfield shift of the 13 C signal of thionil group when compared to those of the free ligand, suggesting the weakening of the CS bond after coordination. The presence of triphenylphosphine was confirmed by the appearance of its typical bands at 1098 cm-1 (CH), 693 cm-1 (ring) e 520 cm-1 (y). TG-DTA curves showed that Pd(II) compounds decompose into Pd0 without the formation of a stable intermediate of metal sulphide. The reaction between N,N´-diphenylthiourea and Cu(II) íons was also investigated in this work. The compound [CuCl(dftu)2]n was characterized by IR and 1 H and 13 C{1 H} NMR spectroscopies. The inhibitory activity of the compounds dftu e [CuCl(dftu)2]n towards the growth of Candida albicans, Candida krusei, Candida parapsilosis e Candida neoformans was also evaluated.
This work deals with the syntheses, spectroscopic characterization of Pd(II) mononuclear compounds obtained from the interaction among [PdCl2(MeCN)2] precursor, N-substituted thioureas (metu = N-methylthiourea; ftu = N-phenylthiourea) and triphenylphosphine (PPh3), in the presence of SCN- e Br - ions. The reaction among [PdCl2(MeCN)2], N-substituted thioureas and triphenylphosphine, in the molar ratio 1:1:1, respectively, yield the complexes [PdCl2(PPh3)(Rtu)] (Rtu = metu, ftu). The compounds [PdX2(Rtu)(PPh3)] (Rtu = metu, ftu; X- = SCN, Br) were prepared from the interaction between the appropriate chloro-complex and KX salts, in molar ratio 1:2, respectively. The coordination of N-substituted thioureas through sulfur atom in the serie [PdX2(PPh3) (Rtu)] (X- = Cl, SCN, Br) was inferred by IR spectroscopy by the shift of C-NHR band to higher frequencies than those of the free ligand, indicating an increasing in the CS bond strenght. NMR spectra also showed the S-coordination by the upfield shift of the 13 C signal of thionil group when compared to those of the free ligand, suggesting the weakening of the CS bond after coordination. The presence of triphenylphosphine was confirmed by the appearance of its typical bands at 1098 cm-1 (CH), 693 cm-1 (ring) e 520 cm-1 (y). TG-DTA curves showed that Pd(II) compounds decompose into Pd0 without the formation of a stable intermediate of metal sulphide. The reaction between N,N´-diphenylthiourea and Cu(II) íons was also investigated in this work. The compound [CuCl(dftu)2]n was characterized by IR and 1 H and 13 C{1 H} NMR spectroscopies. The inhibitory activity of the compounds dftu e [CuCl(dftu)2]n towards the growth of Candida albicans, Candida krusei, Candida parapsilosis e Candida neoformans was also evaluated.
Descrição
Palavras-chave
Química inorgânica, Palladius, Rutilius Taurus Aemilianus, Cobre, Atividade antifúngica, Tiouréias, Inorganic chemistry
Como citar
ARANTES, Francisco Carlos Caliari. Síntese, caracterização e investigação da atividade biológica de complexos de cobre e paládio contendo ligantes N,S doadores. 2009. 97 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Química, 2009.