title: UV-Vis spectroscopic study of preferential solvation and intermolecular interactions in methanol/1-propanol/acetonitrile by means of solvatochromic probes.
abstract: Solvatochromic UV-Vis shifts of four indicators (4-nitroaniline, 4-nitroanisole, 4-nitrophenol and N,N-dimethyl-4-nitroaniline) have been measured at 298.15K in the ternary mixture methanol/1-propanol/acetonitrile (MeOH/1-PrOH/MeCN) in a total of 22 mole fractions, along with 18 additional mole fractions for each of the corresponding binary mixtures, MeOH/1-PrOH, 1-PrOH/MeCN and MeOH/MeCN. These values, combined with our previous experimental results for 2,6-diphenyl-4-(2,4,6-triphenylpyridinium-1-yl)phenolate (Reichardt's betaine dye) in the same mixtures, permitted the computation of the Kamlet-Taft solvent parameters, α, β, and π(*). The rationalization of the spectroscopic behavior of each probe within each mixture's whole mole fraction range was achieved through the use of the Bosch and Rosés preferential solvation model. The applied model allowed the identification of synergistic behaviors in MeCN/alcohol mixtures and thus to infer the existence of solvent complexes in solution. Also, the addition of small amounts of MeCN to the binary mixtures was seen to cause a significant variation in π(*), whereas the addition of alcohol to MeCN mixtures always lead to a sudden change in α and β. The behavior of these parameters in the ternary mixture was shown to be mainly determined by the contributions of the underlying binary mixtures.
authors: Área Departamental de Engenharia Química, Instituto Superior de Engenharia de Lisboa (ISEL), Instituto Politécnico de Lisboa, R. Conselheiro Emídio Navarro, 1, 1959-007 Lisboa, Portugal; Centro de Química e Bioquímica (CQB), Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Ed. C8, Campo Grande, 1749-016 Lisboa, Portugal.
authors: Nélson
authors: N
authors: Nunes
authors: Área Departamental de Engenharia Química, Instituto Superior de Engenharia de Lisboa (ISEL), Instituto Politécnico de Lisboa, R. Conselheiro Emídio Navarro, 1, 1959-007 Lisboa, Portugal; Centro de Química e Bioquímica (CQB), Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Ed. C8, Campo Grande, 1749-016 Lisboa, Portugal.
authors: Ruben
authors: R
authors: Elvas-Leitão
authors: Centro de Química e Bioquímica (CQB), Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Ed. C8, Campo Grande, 1749-016 Lisboa, Portugal. Electronic address: filomena.martins@fc.ul.pt.
authors: Filomena
authors: F
authors: Martins
mesh_terms: D000433:1-Propanol / Q000737:chemistry*; D000097:Acetonitriles / Q000737:chemistry*; D000432:Methanol / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*
chemical_list: D000097:Acetonitriles; D012997:Solvents; D000433:1-Propanol; D000432:Methanol; C032159:acetonitrile
keywords: Kamlet–Taft parameters; Preferential solvation; Solvatochromic probes; Solvent exchange model; Ternary mixture