Authors: Liuqun Gu
Source: ChemRxiv (preprint, 2025-03-05)
Field: Chemistry — Physical and Theoretical Chemistry

Introducing the “Adaptive Delocalization of Charges and Electrons via Dynamic Chemical Bonding” Theory, Chemistry Laws Governing Polyelectrolytes Self-organization in Biological Living Systems And Thermodynamic Behaviors in Synthetic Aqueous Solution Polyelectrolytes including DNA, RNA, protein, and heparin/heparin sulfate proteoglycans play a central role in biological systems. Excellent progress has been achieved in the understanding of polyelectrolytes behaviors at the macroscopic level; electrostatic interaction and counterion/water release is believed to be dominant in the long distance recognition stage and in the association stage respectively. Physics based mean-field theories are dominant, and notably, the Manning-Oosawa counterion condensation theory could well predict the effective charges of polyelectrolytes. However, short-range interactions are often ignored in these theories, resulting in largely unknown atomistic structures of solvated polyelectrolytes and their subsequent solid/liquid complexes upon association. An interdisciplinary and data-driven approach is taken in this work in order to find a framework to predict the counterion locations precisely in each polyelectrolyte and the subsequent polyelectrolyte self-organization behaviors, and the results show that no known theory could be able to address this confusion. A new chemistry theory of “adaptive delocalization of charges and electrons via dynamic chemical bonding” is introduced here for creating the bridges, and the physics-based origin of the theory is also discussed. Our new theory indicates the quantum effect of electron pairs’ orbital exchange is not only common in the electron shell of individual atoms of the periodic table, but also is widely existing in organic molecules/polymers, particularly in the hydrate state or solid state. The new theory is further demonstrated to be able to explain the nature of many non-covalent interactions including Argin-Argin interactions/CH-O interactions/CH-π interactions/alkali metal-O interactions, the atomistic mechanisms of basic synthetic methods (F, O nucleophilic substitutions), hydration/ionization of BrØsted acids and polyelectrolytes, hydrophobic effect, the origin of hydrophobicity of fluorocarbon, competitive ion pairing, selected specific ion effect and the Hofmeister series. With the new set of knowledge, the atomistic counterion structures of polyelectrolyte complexes/complex coacervation are well predicted based on the molecule structures, and the subsequent dynamic change depending on concentration and salt concentration is also predictable qualitatively. The adaptive delocalization theory consisting of three chemistry laws is demonstrated to govern polyelectrolyte self-organization behaviors and thermodynamic behaviours in synthetic aqueous solution, evidenced by a good agreement between theory and reported experimental facts on polyelectrolyte ionization/association (including charge regulation). The broad impact in rational design of drugs (water replacement and multivalent bonding), catalysis (dehydrative amination and asymmetric phase-transfer alkylation), and polymers (solubility in organic solvents, stealth effect (anti-fouling property), cation resulted doping of conjugated polyelectrolytes) with predicting rationales, as well as in advanced understanding of the origin of static charges on polymer surface at molecule level is also discussed. Polyelectrolyte ; Chemical physics ; Counterion ; Delocalized electron ; Chemistry ; Counterion condensation ; Molecular orbital theory ; Computational chemistry ; Statistical physics ; Nanotechnology ; Molecule ; Polymer ; Physics ; Ion ; Materials science ; Organic chemistry ; Molecular orbital Various Chemistry Research Topics ; DNA and Nucleic Acid Chemistry ; Advanced Physical and Chemical Molecular Interactions