Structure and stability of spiro-cyclic water clusters

Abstract

The structure and stability of spiro-cyclic water clusters containing up to 32 water molecules have been investigated at different levels of theory. Although there exist minima lower in energy than these spiro-cyclic clusters, calculations at the Hartree-Fock level, density functional theory using B3LYP parametrization and second order Møller-Plesset perturbation theory using 6-31G* and 6-311++G** basis sets show that they are stable in their own right. Vibrational frequency calculations and atoms-inmolecules analysis of the electron density map confirm the robustness of these hydrogen bonded clusters.

Different Ways of Hydrogen Bonding in Water - Why Does Warm Water Freeze Faster than Cold Water?

“…Most of these investigations have been carried out at the Hartree–Fock (HF), Density Functional Theory (DFT), or perturbation theory level. For example, the investigation of 20-mers (clusters with 20 water molecules), − 25-mers, 30-mers up to 40-mers, − or even 60-mers has to be reported …”

“…An attempt was made by Huang and co-workers to predict the far-infrared spectra of water clusters up to 38 molecules with DFT and to relate them to observed THz spectra . Specific forms of water clusters were investigated by various authors (spiro-cyclic, fullerene-shaped). Frogato and co-workers performed ab initio Born–Oppenheimer molecular dynamics (MD) simulations for 69-mer clusters containing an excess electron .…”

Hydrogen bonded networks in formamide [HCONH2]n (n = 1 − 10) clusters: A computational exploration of preferred aggregation patterns#

“…6 Phenol, water and phenol-water clusters have been used to demonstrate the contribution of hydrogen bonding to their structure and stability and is based on ab initio and DFT calculations and uses topological features of electron density. 7 Studies at HF, B3LYP and MP2 level of theory on helical n = 5 − 20 8 and also on spirocyclic arrangements 9 have demonstrated the multitude of variation possible in # Dedicated to Prof. N Sathyamurthy on his 60th birthday * For correspondence structure when one deals with water clusters. Our study on four different arrangements of water clusters including W1D, W2D, W2D-helical and the caged clusters from Cambridge cluster database n = 2 − 20 has shown how the cooperativity observed in hydrogen bonding is dependant to a large extent on type of arrangement of water molecules.…”

A comprehensive theoretical study of positron binding and annihilation properties of hydrogen bonded binary molecular clusters

“…Theoretical aspects of the present regression analyses represent a possible mechanism to reduce this repulsive interaction via electronic rearrangements induced when the hydrogen bond is formed. For larger hydrogen bonded molecular clusters, their positron affinities and annihilations dependent on structural isomers or the number of hydrogen bonds would be intriguing issues; for instance, small water clusters tend to have cyclic geometries linked by hydrogen bonds in the global minima, 59,60 where all constituents act as the proton donor and acceptor, while larger clusters have numerous local minima containing three-dimensional structures with various hydrogen bonding networks. 61 It may be possible to consider that the cyclic geometry is rather unfavorable or exhibits a small ability for positron binding due to weakening the polarity by accepting a donated hydrogen atom, while larger hydrogen bonded systems are expected to show different positron binding features.…”