Background Hydrogen bonding deeply influences the properties of liquids and solutions, impacting various fields. Understanding hydrogen bonding within complex mixtures is crucial for process optimization. Thermodynamic measurements offer experimental insights into interaction energetics. Density Functional Theory (DFT) calculations provide a molecular-level understanding of the hydrogen bonding networks present in these systems. Methods This research investigates how mixtures containing 4-methyl-2-pentanol and various 1-alkanols behave, focusing on the importance of hydrogen bonding. An Anton Paar SVM 3000 Stabinger viscometer was used to determine the density and viscosity of these mixtures. Free Volume Theory (FVT) helped analyze the viscosity of binary mixtures. Additionally, computational simulations (using the M05–2X/6–311++G** basis sets) were performed to gain deeper insights into the hydrogen bonding characteristics within these mixtures. Significant Finding Analysis of excess molar volumes revealed that these mixtures exhibit a progressive increase in positive excess molar volumes with an extension in the alkyl chain length. This trend demonstrates a high level of agreement with computational data, indicating the reliability of computational methods in predicting and understanding the behavior of such mixtures. Additionally, the study provides insights into the molecular interactions at play, suggesting a basis for future research and potential industrial applications in optimizing separation processes
