Síntese e Caracterização de compostos de coordenação com o herbicida picloram e seus efeitos toxicológicos em Danio rerio (zebrafish)
Data
2022-12-16
Autores
Mecca, Carolina Zeni Pires 
Orientadores
Valle, Eliana Maíra
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Pesticidas são compostos químicos utilizados principalmente na área agrícola, podendo ser também administrados em ambientes domésticos, industriais e urbanos. Podem ser classificados quanto sua estrutura, efeitos de toxicidade ou quanto à natureza da praga controlada. O Picloram é um herbicida da classe dos organoclorados, utilizado no controle de plantas daninhas dicotiledôneas arbustivas e arbóreas e em pastagens. Em sua estrutura química estão presentes átomos de nitrogênio e oxigênio, os quais podem formar ligações com íons metálicos. Esses complexos, se formados no meio ambiente, podem alterar as propriedades do pesticida. Dessa forma, neste trabalho foi sintetizado e caracterizado complexos de coordenação formados entre o herbicida picloram e os íons metálicos cobre e ferro, a fim de avaliar a toxicidade desses novos compostos. Os complexos de cobre-picloram e ferro-picloram, foram caracterizados utilizando as técnicas de espectroscopia eletrônica na região do UV-Vis, espectroscopia vibracional na região do infravermelho, análise elementar e a técnica eletroquímica de voltametria cíclica. Os espectros na região do infravermelho apresentaram deslocamento para frequências menores da banda associada ao νC=N e desaparecimento da banda νO-H, indicando a ligação do metal a este nitrogênio. O complexo cobre-picloram, apresentou uma banda d-d em 763 nm, além das bandas em 225 nm, 241 nm, 300 nm, associadas às transições π→π*. O complexo ferro-picloram apresentou bandas em 257 nm associada a transições π→π* e 297 nm associada a transições n→π*. Estudos eletroquímicos utilizando eletrodo de Carbono vítreo indicaram a presença de um par redox em o,127 V e 0,213V vs Ag/AgCl para o complexo cobre-picloram, e em 0,15 V e 0,01 V vs Ag/AgCl para ferro-picloram, ambos complexos com características quase-reversíveis.
Pesticides are chemical compounds used mainly in the agricultural area, and can also be administered in domestic, industrial and urban environments. They can be classified according to their structure, toxicity effects or the nature of the controlled pest. Picloram is an organochlorine herbicide, used to control bush and tree dicotyledonous weeds and in pastures. Nitrogen and oxygen atoms are present in its chemical structure, which can form bonds with metallic ions. These complexes, if formed in the environment, can change the properties of the pesticide. Thus, in this work, coordination complexes formed between the herbicide picloram and the metallic ions copper and iron were synthesized and characterized, in order to evaluate the toxicity of these new compounds. The copper-picloram and iron-picloram complexes were characterized using electronic spectroscopy techniques in the UV-Vis region, vibrational spectroscopy in the infrared region, elemental analysis and the electrochemical technique of cyclic voltammetry. The spectra in the infrared region showed a shift to lower frequencies of the band associated with νC=N and disappearance of the νO-H band, indicating the binding of the metal to this nitrogen. The copper-picloram complex showed a d-d band at 763 nm, in addition to bands at 225 nm, 241 nm, 300 nm, associated with the π→π* transitions. The iron-picloram complex showed bands at 257 nm associated with π→π* transitions and 297 nm associated with n→π* transitions. Electrochemical studies using glassy carbon electrodes indicated the presence of a redox couple at 0.127 V and 0.213 V vs Ag/AgCl for the copper-picloram complex, and at 0.15 V and 0.01 V vs Ag/AgCl for iron -picloram, both complexes with quasi-reversible characteristics.
Pesticides are chemical compounds used mainly in the agricultural area, and can also be administered in domestic, industrial and urban environments. They can be classified according to their structure, toxicity effects or the nature of the controlled pest. Picloram is an organochlorine herbicide, used to control bush and tree dicotyledonous weeds and in pastures. Nitrogen and oxygen atoms are present in its chemical structure, which can form bonds with metallic ions. These complexes, if formed in the environment, can change the properties of the pesticide. Thus, in this work, coordination complexes formed between the herbicide picloram and the metallic ions copper and iron were synthesized and characterized, in order to evaluate the toxicity of these new compounds. The copper-picloram and iron-picloram complexes were characterized using electronic spectroscopy techniques in the UV-Vis region, vibrational spectroscopy in the infrared region, elemental analysis and the electrochemical technique of cyclic voltammetry. The spectra in the infrared region showed a shift to lower frequencies of the band associated with νC=N and disappearance of the νO-H band, indicating the binding of the metal to this nitrogen. The copper-picloram complex showed a d-d band at 763 nm, in addition to bands at 225 nm, 241 nm, 300 nm, associated with the π→π* transitions. The iron-picloram complex showed bands at 257 nm associated with π→π* transitions and 297 nm associated with n→π* transitions. Electrochemical studies using glassy carbon electrodes indicated the presence of a redox couple at 0.127 V and 0.213 V vs Ag/AgCl for the copper-picloram complex, and at 0.15 V and 0.01 V vs Ag/AgCl for iron -picloram, both complexes with quasi-reversible characteristics.
Descrição
Citação
MECCA, C. Z. P. Síntese e Caracterização de compostos de coordenação com o herbicida picloram e seus efeitos toxicológicos em Danio rerio (Zebrafish). 2022. 64 f. Dissertação (Mestrado em Química) - Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, Diadema, 2022.