Stabilization of free radicals in layer-by-layer nanoarchitectures containing multiple arylenediimides

Autor(es)

Marcon, Rodrigo de Oliveira ^[1] ; Bonvent, Jean-Jacques ^[2] ; Brochsztain, Sergio ^[3]

Afiliação do(s) autor(es)

^[1] Inst Fed Educ Ciencia & Tecnol, Suzano - Brazil

^[2] Univ Fed ABC, Ctr Ciencias Nat & Humanas, Santo Andre, SP - Brazil

^[3] Univ Fed ABC, Ctr Engn Modelagem & Ciencias Sociais Aplicadas, Santo Andre, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: DYES AND PIGMENTS; v. 198, FEB 2022.
• Citações Web of Science: 0

Resumo

Layer-by-layer thin films of arylenediimides were grown on phosphonate-primed silicon and quartz substrates by the zirconium phosphonate method. The method consists in depositing alternated organic/inorganic layers, where the organic layer was a phosphonate-substituted arylenediimide and the inorganic layer was Zr4+. Heterogeneous films with up to 50 layers, containing different imides, were produced. The building blocks were N, N'-bis(2-phosphonoethyl)pyromellitimide (PPMI), N,N'-bis(2-phosphonoethyl)-1,4,5,8-naphthalenediimide (PNDI) and N,N'-bis(2-phosphonoethyl)-3,4,9,10-perylenediimide (PPDI). Thin films with the sequence PPDI/PNDI, PPDI/PPMI, PNDI/PPMI and PPDI/PNDI/PPMI were produced. Organized film growth was observed by UV-visible-NIR spectroscopy (quartz substrates) and ellipsometry (silicon substrates). AFM images showed that the surface of the films was smooth and uniform. The imides in the films were reduced using sodium dithionite as a reducing agent, generating stable radical anions and dianions of the imides. The following species were detected in the absorption spectra of the reduced films: PPDI-center dot, PPDI2-, PNDI-center dot, and PNDI2-. Reduction of the imides in the films was rather slow, as compared to homogeneous solutions. When the reduced films were exposed to atmospheric oxygen, reoxidation took place, which was also much slower than in homogeneous solutions. In conclusion, a mix of aromatic imide reduced species, absorbing through the whole visible range, was produced and stabilized in thin films. (AU)

• Processo FAPESP: 20/15230-5 - Centro de Pesquisa e Inovação de Gases de Efeito Estufa - RCG2I
• Beneficiário: Julio Romano Meneghini
• Modalidade de apoio: Auxílio à Pesquisa - Programa Centros de Pesquisa em Engenharia
• Processo FAPESP: 16/05496-2 - Síntese e caracterização de organosílicas mesoporosas contendo imidas aromáticas e suas aplicações na área de energia
• Beneficiário: Sergio Brochsztain
• Modalidade de apoio: Auxílio à Pesquisa - Regular