Acrylic acid conformers and their interactions with dibutyl ether

Fourier Transform Infrared spectra of pure acrylic acid (ARA), dibutyl ether, and their binary solutions at various acid concentrations have been recorded. Density functional theory calculations on ARA monomers and dimers have been carried out. In addition to the cis–cis and trans–trans dimers, cis–trans dimers also exist in liquid acid. The dimer ring formed by carboxyl group has an asymmetry. The experimental asymmetric and symmetric hydroxyl and carbonyl stretching bands have been assigned. Shifts suffered by the absorption bands in binary solutions have been analyzed in view of the formation of heteromolecular hydrogen bonds.本数据集已测得纯丙烯酸（acrylic acid, ARA）、二丁醚，以及不同酸浓度下二者二元溶液的傅里叶变换红外光谱（Fourier Transform Infrared spectra）。针对丙烯酸单体与二聚体，本研究开展了密度泛函理论（Density functional theory）计算。结果表明，液态丙烯酸中除存在顺式-顺式与反式-反式二聚体外，还存在顺式-反式二聚体；由羧基构成的二聚体环具有不对称性。本工作对实验观测到的不对称与对称羟基、羰基伸缩振动吸收谱带完成了指认，并结合异分子氢键（heteromolecular hydrogen bonds）的形成机制，对二元溶液中吸收谱带的位移现象进行了分析。