Molecular simulation studies of self-assembly for a chromonic perylene dye: All-atom studies and new approaches to coarse-graining

Perylene tetracarboxylic acid bisimides are compounds that show intense visible light absorption and exhibit excellent chemical, photochemical thermal stability. As such, they have been widely used as dyes a range of industrial applications. These also investigated for various applications in aqueous media chromonic liquid crystals: lyotropic systems characterised by the association aromatic mesogenic cores into stacked structures. In this study, we focus on one perylene dye bis-(N,N-diethylaminoethyl) perylene-3,4,9,10-tetracarboxylic diimide dihydrochloride, PER, study its self-assembly solution through both atomistic coarse-grained molecular models. All-atom dynamics simulations demonstrate spontaneous H-aggregate stacks with an interparticle twist between molecules. The coarse-graining complex mesogens introduces wealth subtle complexities presents significant challenge to overcome. Consequently, developed (CG) models using bottom-up top-down approaches: multiscale method (MS-CG) form hybrid force matching (FM) MARTINI 3 field, respectively. We discuss successes/deficiencies these approaches introduce changes improve upon their performance representability. For model, careful optimisation parameters allows it exactly reproduce behaviour including relevant thermodynamic properties solution. CG produced conventional MS-CG treatment, fails most target properties, but implementation potentials combined FM-MARTINI framework recovery correct