Hydrogen Bonding Interaction of Formic Acid‐, Formaldehyde‐, Formylfluoride‐Nitrosyl Hydride: Theoretical Study on the Geometries, Interaction Energies and Blue‐ or Red‐Shifted Hydrogen Bonds

Abstract

AbstractThe hydrogen bonding interaction of formic acid‐, formaldehyde‐, formylfluoride‐nitrosyl hydride complexes was investigated by the density functional theory (DFT) and ab inito method in conjunction with 6‐311++G(2d,2p) basis set. The geometries, vibrational frequencies and interaction energies of the complexes were calculated by both standard and CP‐corrected methods respectively. Moreover, G3B3 method was employed to estimate the interaction energies. There are C–H···O, N–H···O, N–H···F blue‐shifted H‐bonds and red‐shifted O–H···O H‐bond in the complexes. Electron density redistribution and rehybridization contribute to the N–H and C–H blue shifts. All geometric reorganizations contribute to the N–H blue shifts and partial geometric reorganizations contribute to the C–H blue shifts. The geometric reorganizations of the complex C except (H(5)‐O(4)‐C(1) contribute to the O–H red shift. For the N–H blue shifts, the effect of r(N–O) variation on the N–H blue shifts is larger than that of (H‐N‐O variation. Rehybridization plays a dominant role in the degree of N–H blue shifts, whereas the electron density redistribution contributes more to the degree of C–H blue shifts than the other effects do.