The generation of controlled microstructures of functionalized
nanoparticles has been a crucial challenge in nanoscience and nanotechnology.
Efforts have been made to tune ligand charge states that can affect
the aggregation propensity and modulate the self-assembled structures.
In this work, we modeled zwitterionic Janus-like monolayer ligand-protected
metal nanoclusters (J-MPCs) and studied their self-assembly using
atomistic molecular dynamics and on-the-fly probability-based enhanced
sampling simulations. The oppositely charged ligand functionalization
on two hemispheres of a J-MPC elicits asymmetric solvation, primarily
driven by distinctive hydrogen bonding patterns in the ligand–solvent
interactions. Electrostatic interactions between the oppositely charged
residues in J-MPCs guide the formation of one-dimensional and ring-like
self-assembled superstructures with molecular dipoles oriented in
specific patterns. The pertinent atomistic insights into the intermolecular
interactions governing the self-assembled structures of zwitterionic
J-MPCs obtained from this work can be used to design a general strategy
to create tunable microstructures of charged MPCs