Self-healing, luminescent metallogelation driven by synergistic metallophilic and fluorine-fluorine interactions

• Published in: Soft matter 2020-03, Vol.16 (11), p.2795-282
• Main Authors: Kolari, Kalle, Bulatov, Evgeny, Tatikonda, Rajendhraprasad, Bertula, Kia, Kalenius, Elina, Nonappa, Haukka, Matti
• Format: Article
• Language: English
• Subjects: Coordination compounds; Crystallography; Fluorine; Gelation; Gels; Handedness; Ligands; Luminescence; Materials recovery; Mechanical properties; Metal complexes; Nanofibers; NMR; Nuclear magnetic resonance; Optical materials; Optical properties; Optics; Optoelectronics; Perfluoroalkyl & polyfluoroalkyl substances; Photomicrographs; Platinum; Rheological properties; Rheology; Single crystals; Storage modulus; Superstructures; X-ray diffraction
• ISSN: 1744-683X; 1744-6848
• DOI: 10.1039/c9sm02186h

Square planar platinum( ii ) complexes are attractive building blocks for multifunctional soft materials due to their unique optoelectronic properties. However, for soft materials derived from synthetically simple discrete metal complexes, achieving a combination of optical properties, thermoresponsiveness and excellent mechanical properties is a major challenge. Here, we report the rapid self-recovery of luminescent metallogels derived from platinum( ii ) complexes of perfluoroalkyl and alkyl derivatives of terpyridine ligands. Using single crystal X-ray diffraction studies, we show that the presence of synergistic platinum-platinum (Pt Pt) metallopolymerization and fluorine-fluorine (F F) interactions are the major driving forces in achieving hierarchical superstructures. The resulting bright red gels showed the presence of highly entangled three-dimensional networks and helical nanofibres with both ( P and M ) handedness. The gels recover up to 87% of their original storage modulus even after several cycles under oscillatory step-strain rheological measurements showing rapid self-healing. The luminescence properties, along with thermo- and mechanoresponsive gelation, provide the potential to utilize synthetically simple discrete complexes in advanced optical materials. Aggregation and self-assembly of terpyridine platinum( ii ) complex with fluorinated alkyl substituent, driven by synergistic metallophilic and fluorophilic interactions, result in formation of a robust, self-healing, and luminescent gel.