We used solvatochromic compounds to probe solvation in mixtures of water, W, and four ionic liquids (ILs), 1-R-3-methylimidazoliumX, where R ¼ n-butyl or methoxyethyl and X ¼ acetate and chloride; these are denoted as (C 4 MeImAc), (C 3 OMeImAc), (C 4 MeImCl), and (C 3 OMeImCl). Our aim was to investigate the effects on solvation when an ether linkage is substituted for a -CH 2group in the IL side chain. We used the solvatochromic probes 2,6-dichloro-4-(2,4,6-triphenylpyridinium-1-yl)phenolate (WB) and 5nitroindoline, 1-methyl-5-nitroindoline to determine the solvent polarity, E T (WB), and Lewis basicity, SB, respectively. From UV-Vis spectral data, we calculated E T (WB) as a function of the water mole fraction (c W ) at different temperatures; from 15 to 60 C for WB in IL-acetate-W; 25 C for SB and WB in ILchloride-W. For all IL-W mixtures, the dependence of E T (WB) on c W is non-linear and, surprisingly, shows negligible dependence on the nature of the side chain. Values of the SB of IL-W were higher for C 4 MeImX-W than for C 3 OMeImX. A rationale for these results is the deactivation of the ether oxygen due to the formation of intramolecular hydrogen bonds with the hydrogens of the imidazolium ring. Our hypothesis is confirmed by quantum chemistry and molecular dynamics calculations (energy of the conformers and radial distribution functions), density, and 1 H NMR data (chemical shifts, line widths). We attributed the non-linear dependence of the solvatochromic parameters on c W to preferential solvation of the dyes. We treated E T (WB) data with a model that includes the formation of the complex solvent IL-W. Equilibrium constants for solvent exchange in the solvation layer of WB were calculated; their values showed that IL-W is the most efficient solvent species present.

The compound 2,6-diphenyl-4-(2,4,6-triphenylpyridinium-1-yl)phenolate, p-RB, shows distinct colors in different solvents (solvatochromism). The compound 4-(pyridinium-1-yl)phenolate, p-CB, represents the part of p-RB which is responsible for this phenomenon. We compared the solvatochromism of both compounds and also the structurally related 2-(pyridinium-1-yl)phenolate, o-CB, and (2,4-dimethyl-6-(2,4,6-triphenyl-N-pyridinium-1-yl)phenolate, o-RB. In pure solvents, plots of the empirical solvent polarity parameter [E T (probe), kcal/mol] of the different probes correlate linearly with slopes close to unity. That is, these probes are similarly sensitive to specific and nonspecific interactions with the solvents. The solvatochromism of p-CB and o-CB was studied, for the first time, in binary mixtures of water with dimethyl sulfoxide (DMSO) and 1-propanol (1-PrOH). The dependence of E T (probe) on mixture composition was nonideal due to preferential solvation of the probe by one component of the binary solvent mixture. We treated our solvatochromic data using a solvent-exchange model that considers formation of the complex solvents [HOH•••OS(CH 3 ) 2 ] and [HOH•••O(H)-C 3 H 7 ]. The model applies satisfactorily to our data and shows the importance to solvation of hydrogen-bonding and hydrophobic interactions. The preferential solvation of (more hydrophobic) p-RB is more pronounced than that of p-CB or o-CB. The solvent complex [OH 2 •••O(H)-C 3 H 7 ] is more efficient than [OH 2 ••• OS(CH 3 ) 2 ] because of more possibilities of hydrogen bonding.

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Glycal amides were prepared for the first time by reacting 2‐iodo‐D‐glycals with L‐amino acid esters via a Pd‐catalyzed carbonylative cross‐coupling reaction, by using Mo(CO)6 as the carbon monoxide source. Glycal amides were synthesized in moderate to good yields under our optimized conditions. In addition, the acetyl groups of the glucal amides could be readily removed to obtain the corresponding trihydroxy derivatives in good yields.