Cooperative stabilization mechanism and electrostatic evolution in the zero dimensional arsenolite cluster aggregates: a first principles investigation

Abstract

Aggregation mechanism of molecular cage compounds is important in the understanding of cooperative intermolecular interactions which dictate the formation and stability of molecular solids. In this work, a comprehensive first-principles investigations are performed to explore the structural evolution, energetic stability, electronic properties, electrostatic interactions and trajectory based dynamical analysis of the arsenolite (As4O6) cluster series (C1–C5). The structural relaxation and electronic structure calculations are performed using density functional theory (DFT). The thermal stability of the clusters is studied by molecular dynamics (MD) simulations with finite temperature trajectory analysis. The structural descriptors, energetic analysis, reactivity descriptors, charge analyses and molecular electrostatic potential (ΔMEP) analyses are systematically employed to elucidate the aggregation mechanism. These results show that the evolution of clusters is thermodynamically favorable and this evolution is progressively associated with a cooperative stabilization without altering their intrinsic cage geometry. The entire optimized aggregates are also shown to be thermal robust using MD simulations assisted by python trajectories. In this study, the cooperative stabilization mechanism for the evolution of As4O6 clusters is established and fundamental theoretical insights into the self-assembly of molecular cage systems are provided which can form the rational base for the design of cage based molecular crystals and supramolecular materials.