Unveiling molecular interactions in glycerol-based deep eutectic solvents

Autor(es)

Souza, Leticia A. ; de Moraes, Beatriz R. ; de Souza, Rafael M. ; Porto, Gabriel A. L. ; van den Bruinhorst, Adriaan ; Costa Gomes, Margarida ; Ribeiro, Mauro C. C. ; Ando, Romulo A.

• Tipo de documento: Artigo Científico
• Fonte: Physical Chemistry Chemical Physics; v. N/A, p. 9-pg., 2025-04-09.

Resumo

Elucidating the liquid structure of deep eutectic solvents (DES) is crucial to understand how local interactions determine their properties. In this work, the impact of the anion on the liquid structure and local interactions was investigated for mixtures of tetrabutylammonium chloride and bromide ([N4444]Cl and [N4444]Br) with glycerol (Gly). The phase behavior was explored across various compositions using differential scanning calorimetry (DSC) showing that these mixtures form a (meta)stable liquid at room temperature and xsalt = 0.25. At this composition, infrared spectroscopy (IR) revealed strong hydrogen bonding between glycerol and the anion that is more pronounced for chloride than bromide. This finding is supported by the enthalpy of mixing measurements and by quantum chemical calculations. Molecular dynamics (MD) simulations demonstrated that intermolecular hydrogen bonds between glycerol molecules persist, maintaining a long-range liquid structure even in the presence of salt. Far-infrared spectroscopy (FIR) combined with MD simulations revealed changes in local intermolecular dynamics due to a confinement effect caused by the strong anion-glycerol interactions. These results highlight the critical influence of local interactions driven by the anion on DES properties. (AU)

• Processo FAPESP: 20/12054-1 - Espectroscopia vibracional e propriedades de solventes eutéticos profundos
• Beneficiário: Letícia Almeida Souza
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 22/11983-4 - Espectroscopias com intensificação de sinal: nanomateriais, teoria e simulação computacional
• Beneficiário: Mauro Carlos Costa Ribeiro
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 22/01493-0 - Propriedades físicas e termodinâmicas de solventes eutéticos profundos
• Beneficiário: Letícia Almeida Souza
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Iniciação Científica
• Processo FAPESP: 20/06766-9 - Dinâmica molecular de solventes eutéticos profundos
• Beneficiário: Rafael Maglia de Souza
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 20/09250-3 - Ligações de Hidrogênio em Líquidos Iônicos - Espectroscopia Vibracional e Propriedades Físicas
• Beneficiário: Beatriz Rocha de Moraes
• Modalidade de apoio: Bolsas no Brasil - Doutorado