Intermolecular hydrogen bond interactions in the thiourea/water complexes (Thio-(H2O)n) (n = 1, …, 5): X-ray, DFT, NBO, AIM, and RDG analyses

• Published in: Journal of molecular modeling Vol. 26; no. 6; p. 161
• Main Authors: Akman, Feride, Issaoui, Noureddine, Kazachenko, Aleksandr S.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.06.2020; Springer Nature B.V
• Subjects: Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Computer Appl. in Life Sciences; Computer Applications in Chemistry; Density functional theory; Dipole moments; Hydrogen bonding; Hydrogen bonds; Infrared radiation; Mathematical analysis; Molecular interactions; Molecular Medicine; Optical properties; Original Paper; Quantum chemistry; Single crystals; Theoretical and Computational Chemistry; Thermal energy; Thioureas; Vapor phases; Water chemistry; Thiourea; NBO; DFT; X-ray; RDG; AIM
• ISSN: 1610-2940; 0948-5023; 0948-5023
• DOI: 10.1007/s00894-020-04423-3

This study aims to experimentally and theoretically examine the nature and energy of intermolecular bond interactions between thiourea and water molecules using natural bond orbital (NBO), non-linear optical (NLO), atoms in molecules (AIM), and reduced density gradient (RDG) analyses based on the quantum chemical approach and spectroscopic analysis on X-ray and FTIR. Geometry optimizations of Thio-(H 2 O) 1–5 complexes were carried out in the gas phase by B3LYP/6-311++G(d,p) level of density functional theory. The nature of the molecular interactions between the water and thiourea through hydrogen bonding has been investigated using RDG and AIM methods. NBO analysis shows that the Thio-(H 2 O) 5 complex has higher stabilization energy values than the other complexes. The non-linear optical properties, such as dipole moment ( μ ), the polarizability ( α 0 ), and the first hyperpolarizability ( β tot ), and thermodynamic functions, such as entropy ( S ), specific heat capacity ( C v ), and thermal energy ( E ), were calculated using the same method. It was observed that thermodynamic parameters, polarizability, and the first hyperpolarizability increased with the number of water molecules. X-ray diffraction analysis confirmed that thiourea is single crystal, and the thiourea/water complexes are crystalline in nature. Besides, the infrared spectrum shows the existence of water molecules and it is used to get details of the structure of the complex.