Solvatochromism, crystallochromism, and solid state structures of hydrophilically functionalized aromatic amino ketones containing furan and thiophene rings

[4-Di(2-acetoxyethyl)aminophenyl]-2-furylmethanone [Fur(OAc)(2)], [4-di(2-hydroxyethyl)-aminophenyl]-2-furylmethanone [Fur(OH)(2)], and their thiophene analogues, [4-di(2-acetoxyethyl)aminophenyl]-2-thienylmethanone [Thi(OAc)(2)] and [4-di(2-hydroxyethyl)aminophenyl]-2-thienylmethanone [Thi(OH)21, have been synthesized as model compounds for the study of molecular interactions in the solid-state and liquid environments with different polarity. The UV/Vis absorption spectra of these compounds have been studied in 30 solvents of different polarity and hydrogen bonding ability. The solvent dependent UV/Vis spectroscopic band shifts v(max) are analyzed using the empirical Kamlet-Taft solvent parameters pi* (dipolarity/polarizability), alpha (hydrogen bond donating capacity), and beta (hydrogen bond accepting ability) in terms of the well-established linear solvation energy relationship (LSErs): v(max) = (v(max))(0) + spi* + aalpha + bbeta. The solvent independent coefficients s, a, and b and (v(max))(0) have been determined. To evaluate the environmental effects for Fur(OH)(2) and Thi(OH)(2), the UV/Vis spectroscopic behavior of these compounds was also investigated as pure crystal powders and as a guest in ormosil sol-gel glasses. The solid-state structures of the latter compounds were determined by single-crystal X-ray diffraction techniques. The X-ray investigations confirm the existence of qualitatively different intermolecular hydrogen bonds in Fur(OH)2 and Thi(OH)2, which are additionally reflected by the UV/Vis reflectance absorption spectra and are related to the solvatochromism result.