| Texto completo | |
| Autor(es): |
Herrera-Reinoza, Nataly
;
Mowbray, Duncan John
;
Paz, Alejandro Perez
;
dos Santos, Alisson Ceccatto
;
Ferreira, Rodrigo Cezar de Campos
;
de Siervo, Abner
Número total de Autores: 6
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Journal of Physical Chemistry C; v. N/A, p. 12-pg., 2025-03-12. |
| Resumo | |
The production of single-layer polymer ribbons and sheets composed of fused porphyrin rings, named porphene, an analog to graphene, has been aimed over the years as a promising material for applications. Several attempts to polymerize porphyrin rings have used the Ullmann-coupling reaction among the different synthesis routes. In this paper, we report the on-surface synthesis of organometallic molecular chains (1D) and porous networks (2D) from the free-base 5,10,15,20-tetrakis(4-bromophenyl)-porphyrin (H2TBrPP) on Ag(100). We investigated the adsorption of H2TBrPP using a comprehensive multitechnique approach combining scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS), with density functional theory (DFT) based calculations. We find that distinct thermal stimuli applied to the substrate during the deposition lead to different final nanostructures (1D and 2D). This shows an evident thermal selectivity related to porphyrin conformation and substrate interaction, revealing different activation energies. Free-based porphyrins are shown to adopt the so-called "inverted" conformation on Ag(100), which was previously reported exclusively on the Cu(111) surface. Here, we explain the coexistence of these two porphyrins' molecular conformations ("inverted" versus "saddle"). Moreover, based on DFT calculations, we propose a mechanism to overcome the kinetically trapped intermediate organometallic state to allow complete C-C coupling during the Ullmann reaction of porphyrin ring derivatives. (AU) | |
| Processo FAPESP: | 07/54829-5 - Estrutura eletrônica e geométrica de nano materiais: um estudo por radiação sincroton |
| Beneficiário: | Richard Landers |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |
| Processo FAPESP: | 21/04411-1 - Estudo da estrutura eletrônica e atômica de grafeno nanoporoso funcionalizado via síntese química de superfícies |
| Beneficiário: | Alisson Ceccatto dos Santos |
| Modalidade de apoio: | Bolsas no Brasil - Doutorado |
| Processo FAPESP: | 07/08244-5 - Estudo das propriedades magnéticas de filmes ultrafinos e nanopartículas de Pd e PdAu via XMCD |
| Beneficiário: | Abner de Siervo |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |