Design, synthesis, and analysis of multi-layered 3D fluorescent polymers derived from anthracene and naphthalene structural units

TL;DR

Scientists created new 3D fluorescent polymers using anthracene and naphthalene units, which show strong light emission and potential for optoelectronic applications.

Contribution

The paper introduces a novel class of multilayered 3D fluorescent polymers with aggregation-induced emission and tunable photophysics.

Findings

The polymers exhibit aggregation-induced emission (AIE) and strong UV absorption due to extended π-conjugation.

Transmission electron microscopy reveals nanoscale domains with short-range ordering.

Density-functional calculations show layer-dependent π-delocalization and tunable HOMO–LUMO separation.

Abstract

A new class of polymers integrating anthracene and naphthalene was designed and synthesized. The materials adopt compact multilayered architectures that exploit extended π-conjugation and the rigidity of polycyclic aromatic hydrocarbon units. Optimized Suzuki–Miyaura polycondensation afforded polymers characterized by 1H/13C NMR and gel permeation chromatography (GPC). Transmission electron microscopy (TEM) images reveal nanoscale domains with locally lamellar-like contrast features in selected regions, consistent with short-range ordering rather than uniform long-range periodicity across the entire sample. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) indicate decomposition above 250 °C and glass-transition behavior typical of thermally robust aromatic polymers. UV-vis absorption revealed strong π–π* transitions in the UV; steady-state fluorescence displayed pronounced aggregation-induced emission (AIE) in the aggregated state. Dynamic light scattering (DLS) yielded intensity-weighted apparent hydrodynamic diameters from the nano-to sub-micrometer range with sample-dependent mono- or bimodal distributions, consistent with aggregate-rich dispersions that accompany the AIE response. Scanning electron microscopy (SEM) suggests layered surface textures without obvious macroscopic phase separation. Density-functional calculations indicate a layer-dependent shift toward more uniform π-delocalization; monomer sequence and layer number modulated the HOMO–LUMO separation. Overall, these multilayer 3D polymers combine strong luminescence, thermal stability, and tunable structure-photophysics, suggesting potential for optoelectronic and sensing applications.

New anthracene–naphthalene multilayer polymers from Suzuki polycondensation of tailored dibromonaphthalenes show water-triggered AIE turn-on and locally ordered nanoscale domains for optical sensing and optoelectronics.

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