Investigating the electronic excitations in Polyoxoniobates: (Nb6O19)8-, (Nb10O28)(6-) and (XNb12O40)(Y) with (X = As, P, Si, Ge) and (Y=15-and 16-)

Autor(es)

Steffler, Fernando ^[1] ; Haiduke, Roberto L. A. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Quim & Fis Mol, Inst Quim Sao Carlos, Ave Trabalhador Sao Carlense 400, CP 780, BR-13560970 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Molecular Structure; v. 1246, DEC 15 2021.
• Citações Web of Science: 0

Resumo

Polyoxoniobates are polyoxometalates with applications in catalysis, water splitting and organic reactions such as condensation of Knoevenagel and Cycloaddition of CO2. Actually, range-separated hybrids (RSHs) are being indicated for the description of electronic excitations within Time Dependent Density Func-tional Theory (TDDFT), mainly in systems presenting charge - transfer transitions. Here, this protocol is applied for studying ultraviolet - visible (UV/Vis) bands of polyoxoniobates in aqueous solution. Al-though the experimental data for comparison are scarce, the RSHs investigated were particularly suc-cessful, providing wavelength deviations usually smaller than 30 nm. Results indicate that wavelengths change slightly among all these compounds (22 - 35 nm), with the following sequence: {[}Nb10O28](6-) < {[}Nb6O19]8- < {[}SiNb12O40](16-) = {[}AsNb12O40](15-) = {[}PNb12O40](15-) < {[}GeNb12O40](16-). Atomic charges in internal oxygens and heteroatoms are nearly insensitive to these transitions. In addition, the largest elec-tronic charge transfer from oxygens to niobium occurs in {[}Nb6O19](8-) (0.39 e ), followed by {[}Nb10O28](6-) (0.31 e ), {[}SiNb12O40](16-) (0.27 e ), {[}PNb12O40](15-) (0.23 e ), {[}AsNb12O40](15-) (0.11 e ) and {[}GeNb12O40](16-) (0.06 e ). (C) 2021 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 14/23714-1 - Cálculos relativísticos de estrutura eletrônica para avaliação de novos conjuntos de funções de base sem prolapso variacional
• Beneficiário: Roberto Luiz Andrade Haiduke
• Modalidade de apoio: Auxílio à Pesquisa - Regular