| Abstract: | Weakly bound dimer complexes FH—CO and FH—OC were investigated using various ab initio and density function theory (DFT) methods. This study compares the strengths of the H—C H‐bond in FH—CO and the H—O H‐bond in FH—OC. The energy difference between dimers, the H‐bond energy, the inter‐monomer distance, the inter‐monomer vibration frequencies, the red shift of the HF stretching frequency, and the elongation of HF bond, all demonstrate that the H—C H‐bond is stronger than the related H—O H‐bond, according to all methods. The calculated Gibbs energies of the formation of the two dimers show that the weakly bound complexes are unstable at room temperature (T = 298 K) and ordinary pressure (P = 1 atm). However, decreasing T or increasing P monotonically decreases ΔG and increases the related equilibrium constant, K, of their dimer formation. |
