Angular geometries and other properties of hydrogen-bonded dimers: a simple electrostatic interpretation of the success of the electron-pair model

Formation of a pre-reaction hydrogen-bonded complex and its significance in the potential energy surface of the OH + SO2→ HOSO2 reaction: A computational study

“…47 On the contrary, since OH rotor has a very low moment of inertia compared with SO 2 , for any change in the potential, the response of OH in adjusting its position will be prominent. 47 As there is a change in the potential in moving from the complex to the transition state, the 2D structure of the pre-reaction complex has now changed to the 3D transition state structure and the only signi¯cant observable change is the position of OH. We have also observed that for the atomic spin density of the fragment, OH is conserved on the OH fragment for the transition state as well as the pre-reaction complex.…”

How weak an acid can be? Variations of H-bond and/or van der Waals Interaction of Weak Acids

“…However, this kind of C-H bond dissociation requests a strong base (beside additional structural prerequisites). By now the arsenal of well characterized organic reactions involving the dissociation of selected C-H covalent bonds fertilized many areas of modern synthetic organic chemistry [9][10][11][12][13][14]. Numerous X-ray structures have clearly indicated the existence of C-H…O interactions (Figure1) even for cases where the acceptor O-atom is not a a strong base [15].…”

Electrostatic Potential and a Simple Extended Electric Dipole Model of Hydrogen Fluoride as Probes of Non-Bonding Electron Pairs in the Cyclic Ethers 2,5-Dihydrofuran, Oxetane and Oxirane

“…In each of the three complexes, HF forms a hydrogen bond to the O atom and there is a pyramidal configuration at O formed by the two equivalent C-O bonds and the O· · · H hydrogen bond. The success of the extended electric dipole moment model of HF in reproducing the experimentally determined function V(φ) versus φ for H2O⋯HF and for predicting φe values for H2S and H2CO [7] led to the proposal of the following corollary to the rules: As long as the hydrogen bond in B⋯HF is sufficiently weak that the electric charge distributions of B and HF are essentially unperturbed, the HF axis acts as a probe for the direction of a nonbonding (or π-bonding) pair on B.…”

“…Note that now φ e = ±55 • . The success of the extended electric dipole moment model of HF in reproducing the experimentally determined function V(φ) versus φ for H2O⋯HF and for predicting φe values for H2S and H2CO [7] led to the proposal of the following corollary to the rules:…”