The O···H intramolecular hydrogen bond in 4‐X‐2‐hydroxybenzaldehydes: The relationships between geometrical parameters,estimated binding energies,and NMR data

The relationships among geometrical parameters, estimated binding energies, and nuclear magnetic resonance data in –C?O···H? O? intramolecular H‐bond of some substituted 2‐hydroxybenzaldehyde have theoretically been studied by B3LYP and MP2 methods with 6‐311++G** and AUG‐cc‐PVTZ basis sets. All substituents increase estimated hydrogen bond energies E_HBs (with the exception of NO₂ and C₂H₅), which are in good correlation with geometrical parameters, topological properties of electron density calculated at O···H bond critical points and ring critical points by using atoms in molecules method, the results of natural bond orbital analysis, and calculated nuclear magnetic resonance data. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010