title: Molecular interpretation of water structuring and destructuring effects: hydration of alkanediols.
abstract: Molecular electrostatic potential (MESP) guidelines are employed for understanding the reactivity and hydration patterns in alkanediol molecules. The deeper oxygen lone pair MESP minima indicate stronger basicity of 1,n-diols and 2,4-pentanediol (2,4-PeD) as compared to that of vicinal diols. The existence and strength of the intramolecular hydrogen bond in diols are gauged in terms of the electron density at the bond saddle points. A model named electrostatic potential for intermolecular complexation (EPIC) is used for generating the structures of hydrated complexes, which are subsequently subjected to ab initio calculations at Møller-Plesset second-order perturbation level of theory. Further, the nature of water...water as well as diol...water interactions is appraised employing many-body energy decomposition analysis. It is seen that water...water interactions are more favorable in vicinal diol...6H(2)O than those in 1,n-diol...6H(2)O (n=3, 4, 5,...) complexes. Exactly opposite trends are shown by diol...water interaction energies. Thus vicinal diols, being more effective at strengthening water...water network, are expected to act as water structuring agents, whereas the non-vicinal diols are expected to be water destructuring agents.
authors.affiliation: Department of Chemistry, University of Pune, Ganeshkhind, Pune-411 007, India.
authors.forename: Milind M
authors.initials: MM
authors.lastname: Deshmukh
authors.forename: Nandhibatla V
authors.initials: NV
authors.lastname: Sastry
authors.forename: Shridhar R
authors.initials: SR
authors.lastname: Gadre