Theoretical characterization of electronic structures and properties of C-F·H-C pseudohydrogen bonds

Abstract

The weak intermolecular interactions between 2-F-tetrahydrofuran and imidazole, pyrimidine, adenine, and guanine were studied theoretically using density functional B3LYP/6-311++G** and HF/6-311++G** methods. The results showed that both conventional N· H hydrogen bond and C-F· H-C pseudohydrogen bond (PHB) structures coexist in the four complexes. The weak intermolecular interaction energies indicate that the relative stabilities of the four complexes are in the order guanine· F & imidazole· F & adenine· F & pyrimidine· F. The characteristics of the four PHBs were determined using geometry optimizations, stretching vibrational frequencies, and natural bond orbital and electron density topological properties calculations. The most important result is that the F group of 2-F-tetrahydrofuran can activate the C-H to accept electrons from another molecule, and C-F· H-C PHB formation is relatively favorable. © 2012 The Author(s).