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Full-Text Articles in Physical Sciences and Mathematics
Proton‐Donor Properties Of Water And Ammonia In Van Der Waals Complexes. Be–H2o And Be–Nh3, G. Chalasinski, M. M. Szczesniak, Steve Scheiner
Proton‐Donor Properties Of Water And Ammonia In Van Der Waals Complexes. Be–H2o And Be–Nh3, G. Chalasinski, M. M. Szczesniak, Steve Scheiner
Chemistry and Biochemistry Faculty Publications
The potential energy surfaces (PES) of Be–H2O and Be–NH3 are studied with particular attention to characterization of proton‐donor properties of water and ammonia. Calculations were performed by means of both supermolecular and intermolecular Møller Plesset perturbation theory. The Be–H2O PES reveals two van der Waals minima: the C2v minimum (De=176 cm−1, Re=6.5 bohr), and the H‐bonded minimum (De=161 cm−1, Re=7.5 bohr), separated by a barrier of 43 cm−1 at the T‐shaped configuration. The Be–NH3 PES reveals only …
Proton–Donor Properties Of Water And Ammonia In Van Der Waals Complexes With Rare‐Gas Atoms. Kr–H2o And Kr–Nh3, G. Chalasinski, M. M. Szczesniak, Steve Scheiner
Proton–Donor Properties Of Water And Ammonia In Van Der Waals Complexes With Rare‐Gas Atoms. Kr–H2o And Kr–Nh3, G. Chalasinski, M. M. Szczesniak, Steve Scheiner
Chemistry and Biochemistry Faculty Publications
The perturbation theory of intermolecular forces in conjunction with the supermolecular Møller–Plesset perturbation theory is applied to the analysis of the potential‐energy surfaces of Kr–H2O and Kr–NH3 complexes. The valleylike minimum region on the potential‐energy surface of Kr–H2O ranges from the coplanar geometry with the C2 axis of H2O nearly perpendicular to the O–Kr axis (T structure) to the H‐bond structure in which Kr faces the H atom of H2O. Compared to the previously studied Ar–H2O [J. Chem. Phys. 94, 2807 (1991)] the minimum has more …
Comparison Of Proton Transfers In (S2h5)+ And (O2h5)+, L. Bigham, Steve Scheiner
Comparison Of Proton Transfers In (S2h5)+ And (O2h5)+, L. Bigham, Steve Scheiner
Chemistry and Biochemistry Faculty Publications
The energetics and electronic rearrangements associated with proton transfer between S atoms in (H2S–H–SH2)+ are calculated using ab initio molecular orbital methods and compared with similar data in the first‐row analog (H2O–H–OH2)+. The full potential energy surface of (S2H5)+, calculated as a function of the H‐bond length as well as the position of the proton, contains two equivalent minima separated by a small energy barrier, whereas the surface of (O2H5)+ contains a single minimum corresponding to a symmetric …
Proton Transfers Between First‐ And Second‐Row Atoms: (H2ohsh2)+ And (H3nhsh2)+, Steve Scheiner
Proton Transfers Between First‐ And Second‐Row Atoms: (H2ohsh2)+ And (H3nhsh2)+, Steve Scheiner
Chemistry and Biochemistry Faculty Publications
Ab initio molecular orbital methods are used to study the transfer of the central proton along the hydrogen bonds in (H2OHSH2)+ and (H3NHSH2)+. Proton transfer potentials are generated using the 4‐31G∗ basis set at the Hartree–Fock level for various values for the hydrogen bond length R(XS). Full geometry optimizations are carried out at each stage of proton transfer. The barrier to proton transfer increases as the hydrogen bond is lengthened. For a given bond length, the highest barriers are observed for transfer from …
Comparison Of Proton Transfers In Cationic Heterodimers And Homodimers Of Nh3 And Oh2, Steve Scheiner
Comparison Of Proton Transfers In Cationic Heterodimers And Homodimers Of Nh3 And Oh2, Steve Scheiner
Chemistry and Biochemistry Faculty Publications
Ab initio molecular orbital methods are used to study proton transfers in the cationic heterodimer (H3NHOH2)+ as well as the symmetric homodimers (H2OHOH2)+ and (H3NHNH3)+. All calculations are carried out at the Hartree–Fock level with a 4‐31G basis set to ensure consistency. For proton transfers along a linear hydrogen bond in the heterodimer, asymmetric single‐well potentials with a minimum corresponding to (NH4)+(OH2) are obtained for R(NO) distances of less than 2.85 …
Proton Transfers In Hydrogen‐Bonded Systems. Vi. Electronic Redistributions In (N2h7)+ And (O2h5)+, Steve Scheiner
Proton Transfers In Hydrogen‐Bonded Systems. Vi. Electronic Redistributions In (N2h7)+ And (O2h5)+, Steve Scheiner
Chemistry and Biochemistry Faculty Publications
Electronic rearrangements accompanying transfer of the central proton between the two XHn units of (H3NHNH3)+ and (H2OHOH2)+ are studied using ab initio molecular orbital methods. Electron density difference maps are calculated by subtracting the density of the equilibrium structure (X–H‐‐‐X) from that of the midpoint geometry (X‐‐H‐‐X) using the split‐valence 4‐31G basis set. Some of the features revealed by the maps are common to both systems while others indicate significant differences between nitrogen and oxygen. Decomposition of the total electron density into …