London Dispersion versus Intramolecular Hydrogen Bond in Bis-Pyridines: How Accurate Is DFT for Competing Noncovalent Interactions in the Condensed Phase?

ABSTRACT: We report a systematic investigation of noncovalent interactions-particularly an intramolecular hydrogen bond and London Dispersion forces-in singly protonated bis-pyridines, studied across solution and crystalline states. Building on our previous gas-phase study, we combine variable-temperature ¹H NMR spectroscopy, single-crystal X-ray diffraction, and density functional theory (DFT) calculations. The measured ¹H NMR chemical shifts of the acidic proton serve as a solution-phase structural readout, which we correlate with an independent crystallographic metric. By systematically varying the linker (-CH₂-, -O-, and -CH₂CH₂-) and the pendant substituents (H, methyl, tert-butyl), we examine how increasingly bulky "dispersion energy donor

SUBMITTER: Savoy A 

PROVIDER: S-EPMC12648470 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature