Revisiting the Linear Relationship between Hydroxyl Stretch Frequency and Bond Length: A Data-Driven Analysis Connecting Structure to Electrostatic Potential

The correlation between O–H stretching frequency and bond length has a long history of study and continues to attract significant research interests, yet remains incompletely understood. Here, we examine this relationship using a computational analysis of 604 carboxylic acid molecules capable of forming intramolecular hydrogen bonds. By categorizing molecules into groups based on ring strain, we identify structural factors influencing hydrogen bond strength and bond geometry. Strong linear correlations are observed between vibrational frequencies and electrostatic potential (ESP) extrema, highlighting frequency as a practical proxy for local electrostatic properties. These findings clarify fundamental structural relationships and suggest spectroscopic methods for predicting chemically relevant molecular properties.