Perturbation of Local Solvent Structure by a Small Dication:  A Theoretical Study on Structural, Vibrational, and Reactive Properties of Beryllium Ion in Water

Abstract

A molecular based understanding of beryllium chemistry in the context of biomolecules is necessary for gaining progress in prevention and treatment of chronic beryllium disease. One aspect that has hindered the theoretical progress has been the lack of a simple classical two-body potential for the aqueous beryllium ion (Be2+) to be used with biomolecular simulations. We provide new parameters for Be2+ that capture the structural and reactive properties of this small dication. Using classical molecular dynamics simulations, we show that these parameters reproduce the correct radial distribution function and coordination numbers for this cation in explicit aqueous solution when compared to published diffraction and NMR measurements. The geometrical parameters obtained using classical simulations are also in agreement with ab initio calculations. We successfully predict the vibrational modes of the tetra aqua Be2+ dication from ab initio calculations on solvated structures obtained from the simulations. The calculated vibrational modes show better agreement with experiments compared to any published work. This new potential also produces a well-established hydrogen bonding between the first and second solvation shells. More importantly, when the molecular dynamics (MD) and ab initio results are interpreted in concert, the dynamics and nature of interactions between the first and second shells capture the pivotal role they play on the reactivity of aqua-Be complexes.

An ab initio study of beryllium(II) hydration

“…As part of their study of chronic beryllium disease and the role that beryllium-protein binding may play, Snyder and coworkers carried out a molecular dynamics simulation with the CHARMM force field [26]. Surprisingly, a classical MD simulation using Lennard-Jones and Coluombic potential two-body terms only was able to reproduce reasonably the hydration number and Be-O distance [27]. The QMCF method of Rode also gave a short Be-O distance [28].…”

Cooperativity between hydrogen bonds and beryllium bonds in (H2O)nBeX2 (n = 1–3, X = H, F) complexes. A new perspective

“…In some of these studies it has been suggested that Be acts as a ''tetrahedral proton'' displacing H + from strong hydrogen bonds. [21][22][23][24][25] This implies that strong hydrogen bonds are ideal binding sites for Be. Besides, this new binding mechanism seems to explain how Be migrates through a biological system passing from one protein to another via exchangeable hydrogen bonds.…”

“…One of the most important findings is that the complex in which Be is tetracoordinated to the two X ligands and the two imidazole molecules (structure b in Scheme 1) is not the global minimum of the potential energy surface, as might be expected. 49 Hence, although Be has a clear propensity to be tetracoordinated, 21,23,24,50,51 the formation of beryllium bonds may favor arrangements in which the level of coordination is clearly smaller, because of the significant electron density redistribution associated with the formation of beryllium bonds.…”

“…Since water is ubiquitous in the physiological medium significant attention was paid to the way in which Be 2+ interacts with water. It seems well established that Be 2+ forms tetracoordinated clusters when interacting with water, 23,51,52 followed by the deprotonation of one of the water molecules. It is not evident however whether this arrangement would be preferred when Be is already attached to two ligands but is still able to form stable beryllium bonds.…”

Highly sensitive and selective detection of beryllium ions using a microcantilever modified with benzo-9-crown-3 doped hydrogel

“…Beryllium has been widely used in industry for manufacturing nuclear components, electronic devices, golf clubs, aircraft brakes, X-ray tubes, high-temperature ceramics, and structural components in satellites and space shuttles. 1 As beryllium is processed from its oxide form in nature, beryllium aerosol particulates are always generated, which would cause documented illnesses of chronic beryllium disease (CBD) in individuals working in and around the beryllium processing site. The primary hazard associated with beryllium processing is the inhalation of beryllium particles.…”