Síntese e caracterização do complexo formado através da reação entre o dicloreto de difenilestanho e ácido cítrico e sua atividade fungicida

Abstract

Tin-based compounds, specially the organometallic ones, have been used for a number of purpores, from biocides to medicines, useful in the câncer treatment. Application of such compounds in patogenic agents has increased gradually, due to their effetiveness and non-toxicity aften degradation. Therefore, it is of interest to search for novel actives against those agents. Thus, the goals of this work were: 1) to synthesize a complex from the reaction between diphenyltin dichloride and citric acid; 2) to characterize such complex through using infrared spectroscopy and melting point; 3) to perform in vitro tests by applying the reagents and the complex obtained on Fusarium oxysporum sp. phaseoli, Colletotrichum truncatun, Alternaria alternata, Cylindrocladium, Phythium, Ramularia e Rhyzopus, as well as to verity their influence on the fungi growth. The resuts showed that the obtained complex is thermically more stable than diphenyltin and citric acid. Also, the spectroscopic behaviour of the complex differs from the starting materials, which suggests its formation. According to the biological tests, the complex was just a few active against fungi, with growth average and index of speed of miceliar growth close to witness, excepting for the 1000 mg L-1 dosage. Similar behaviour was observed for the citric acid. However, an efficient inhition was obtained for the treatment with diphenyltin dichloride, mostly at the 100 and 1000 mg L-1 dosage (excepting Rhizopus at the 100 dosage, which presented potential of inibition larger than the diphenyltin dichloride).