Synthesis of several C₆₀-(antenna)_x conjugates was performed to demonstrate high flexibility in the design of organic nonlinear optical (NLO) nanostructures showing broadband characteristics with capability to absorb light over a wide range of wavelengths. It was achieved by covalent attachment of a hybrid combination of two types of light-harvesting fluorescent antenna chromophores on a C₆₀ cage. Ultrafast photoresponsive intramolecular Föster resonance energy-transfer among antenna units and shared excited energy-accepting C₆₀ cage is proposed as a plausible mechanism to enhance the broadband NLO ability. Characterization of the branched triad C₆₀(>DPAF-C₁₈)(>CPAF-C_2M) and the tetrad C₆₀(>DPAF-C₁₈)(>CPAF-C_2M)₂ was carried out by various spectroscopic techniques. These compounds showed approximately equal extinction coefficients of optical absorption over 400‒550 nm that corresponds to near-IR two-photon based excitation wavelengths at 780‒1100 nm. These nanomaterials may be utilized in NLO coatings for achieving efficient light-transmittance reduction at the same NIR wavelengths.

Date Published: 7 October 2014
PDF: 10 pages
Proc. SPIE 9181, Light Manipulating Organic Materials and Devices, 918105 (7 October 2014); doi: 10.1117/12.2060935

Published in SPIE Proceedings Vol. 9181:
Light Manipulating Organic Materials and Devices
Jean-Michel Nunzi, Editor(s)