Synthesis of Photoswitchable Magnetic Au-Fullerosome Hybrid Nanomaterials for Permittivity Enhancement Applications

3D-Conformer of Tris[60]fullerenylated cis-Tris(diphenylamino-fluorene) as Photoswitchable Charge-Polarizer on GHz-Responsive Trilayered Core-Shell Dielectric Nanoparticles

Novel 3D-configurated stereoisomers cis-cup-tris[C₆₀>(DPAF-C₉)] and trans-chair-tris[C₆₀>(DPAF-C₉)] were designed and synthesized in good yields. The former, with three C₆₀> cages per molecule facing at the same side of the geometrical molecular cup-shape, was proposed to provide excellent binding interaction forces at the gold surface of core-shell γ-FeO_x@AuNP nanoparticles and to direct the subsequent formation of a fullerene cage array (defined as fullerosome). Upon photoactivation of the Au-layer and cis-cup-tris[C₆₀>(DPAF-C₉)] itself, the degree of photoinduced intramolecular e⁻-transfer from DPAF to a C₆₀> moiety was found to be largely enhanced by the accumulated plasmonic resonance energy at the near-field surface. Distribution of resulting negative charges along the outer (C₆₀>)-derived fullerosome shell layer of the trilayered NPs was correlated with the detected photoswitchable dielectric amplification phenomena using white LED light at 1.0 GHz.

Novel photoswitchable dielectric properties on nanomaterials of electronic core-shell γ-FeOx@Au@fullerosomes for GHz frequency applications

We unexpectedly observed a large amplification of the dielectric properties associated with the photoswitching effect and the new unusual phenomenon of delayed photoinduced capacitor-like (i.e. electric polarization) behavior at the interface on samples of three-layered core-shell (γ-FeOx@AuNP)@[C60(>DPAF-C9)](n)2 nanoparticles (NPs) in frequencies of 0.5-4.0 GHz. The detected relative dielectric constant amplification was initiated upon switching off the light followed by relaxation to give an excellent recyclability. These NPs having e(-)-polarizable fullerosomic structures located at the outer layer were fabricated from highly magnetic core-shell γ-FeOx@AuNPs. Surface-stabilized 2 in a core-shell structure was found to be capable of photoinducing the surface plasmonic resonance (SPR) effect by white LED light. The accumulated SPR energy was subsequently transferred to the partially bilayered C60(>DPAF-C9) fullerosomic membrane layer in a near-field (∼1.5 nm) region without producing radiation heat. Since the monostatic SAR signal is dielectric property-dependent, we used these measurements to provide evidence of derived reflectivity changes on a surface coated with 2 at 0.5-4.0 GHz upon illumination of LED white light. We found that a high, >99%, efficiency of response amplification in image amplitude can be achieved.