Tunable Chiral D4-Symmetric Phthalocyanines with Rationally Designed Aggregation for Near-Infrared Circularly Polarized Luminescence.

Chiral phthalocyanines hold significant promise for chiroptical and supramolecular materials; however, reported examples remain sporadic, and no general synthetic platform has been available to systematically control their structural and functional properties. Here, we report a practical and general synthesis of D4-symmetric chiral phthalocyanines from commercially available H8-BINOL. This modular route provides direct access to a broad palette of chiral architectures, enabling systematic investigation of how substituents govern supramolecular assembly. We found that aggregation behavior can be predictably tuned through simple structural modifications. Single-crystal X-ray diffraction analysis guided the design of tailored noncovalent interactions that promote spontaneous and selective J-type aggregation into well-defined chiral helices. The resulting supramolecular structures display narrowband near-infrared fluorescence (fwhm = 15 nm) and pronounced circularly polarized luminescence (CPL), with dissymmetry factors (glum) of up to 0.01. Notably, the CPL signal of the aggregates remains detectable at nanomolar concentrations down to 500 nM, demonstrating the high chiroptical efficiency of these materials and their potential for low concentration applications.