Broadband Two-Photon Absorption Characteristics of Highly Photostable Fluorenyl-Dicyanoethylenylated [60] Fullerene Dyads (Postprint)
Abstract
We synthesized four C60-(light-harvesting antenna) dyads C60 (>CPAF-Cn) (n = 4, 9, 12, or 18) 1-Cn for the investigation of their broadband nonlinear absorption effect. Since we have previously demonstrated their high function as two-photon absorption (2PA) materials at 1000 nm, a different 2PA wavelength of 780 nm was applied in the study. The combined data taken at two different wavelength ranges substantiated the broadband characteristics of 1-Cn. We proposed that the observed broadband absorptions may be attributed by a partial -conjugation between the C60 > cage and CPAF-Cn moieties via endinitrile tautomeric resonance, giving a resonance state with enhanced molecular conjugation. This transient state could increase its 2PA and excited-state absorption at 800 nm. In addition, a trend of concentration-dependent 2PA cross-section (2 ) and excited-state absorption magnitude was detected showing a higher value at a lower concentration that was correlated to increasing molecular separation with less aggregation for dyads C60(>CPAF-C18) and C60(>CPAF-C9), as better 2PA and excited-state absorbers.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 14, 2016
- Accession Number
- AD1034581
Entities
People
- Long Y Chiang
- Loon-Seng Tan
- Min Wang
- Seaho Jeon
- Thomas M Cooper
- Wei Ji
Organizations
- University of Massachusetts Lowell