Maharana Samaresh, Maharana Rajat Rajiv, Samanta Kousik, Mishra Sujata
Department of Chemistry, Institute of Technical Education and Research (ITER), Siksha 'O' Anusandhan Deemed to be University, Khandagiri Square, Bhubaneswar 751030, Odisha, India.
Prananath College (Autonomous), Khordha 752057, Odisha, India.
ACS Omega. 2025 Aug 8;10(32):36041-36055. doi: 10.1021/acsomega.5c03618. eCollection 2025 Aug 19.
Hydrophobic deep eutectic solvents (HDESs) are emerging as potential substitutes for traditional organic solvents. Their distinctive features, namely, low aqueous solubility and tunable structures, make them suitable for diverse uses. The present work describes the synthesis and spectroscopic (H NMR, C NMR, and FTIR) characterization of l-proline-carboxylic acid-based HDESs. Their thermophysical behavior in terms of parameters such as density, dielectric constant, conductivity, and refractive index has been examined. Density functional theory calculations with an emphasis on geometry optimization, HOMO-LUMO analysis, quantum theory of atoms in molecules (QTAIM), and analysis of the noncovalent interactions (NCI) were undertaken to gain structural insights, e.g., molecular stability, electronic properties, and intermolecular interactions. Among the three l-proline-based HDESs, l-proline:HexA shows the highest stability, demonstrated by its maximum stabilization energy value of -24.453 kcal mol. The findings suggest that l-proline-based HDESs demonstrate stable intermolecular interactions, favorable electronic properties, and advantageous thermophysical characteristics, making them appealing for a variety of potential applications.
疏水型低共熔溶剂（HDESs）正逐渐成为传统有机溶剂的潜在替代品。它们具有独特的特性，即低水溶性和可调节的结构，这使其适用于多种用途。本工作描述了基于L-脯氨酸-羧酸的HDESs的合成及光谱表征（1H NMR、13C NMR和FTIR）。研究了它们在密度、介电常数、电导率和折射率等参数方面的热物理行为。进行了密度泛函理论计算，重点是几何优化、HOMO-LUMO分析、分子中的原子量子理论（QTAIM）以及非共价相互作用（NCI）分析，以获得结构方面的见解，例如分子稳定性、电子性质和分子间相互作用。在三种基于L-脯氨酸的HDESs中，L-脯氨酸：己酸表现出最高的稳定性，其最大稳定化能值为-24.453 kcal/mol即可证明。研究结果表明，基于L-脯氨酸的HDESs表现出稳定的分子间相互作用、良好的电子性质和有利的热物理特性，使其在各种潜在应用中具有吸引力。
