Synthesis, Spectroscopic and Nonlinear Optical Properties of Multiple [60]Fullerene–Oligo(p‐phenylene ethynylene) Hybrids

Abstract

A series of multiple [60]fullerene terminated oligo(p-phenylene ethynylene) (OPE) hybrid compounds has been synthesized through a newly developed in situ ethynylation method. Structural and magnetic shielding properties of the highly unsaturated carbon-rich C(60) and OPE scaffolds were characterized by 1D and 2D NMR spectroscopic analyses. Electronic interactions between the [60]fullerenes and the OPE backbones were investigated by UV/Vis spectroscopic and cyclic voltammetry (CV) experiments. Our studies clearly show that although the multiple [60]fullerene groups are connected via pi-conjugated OPE frameworks, they present diminutive electronic interactions in the ground state, and the electronic behavior of the [60]fullerene cages are only affected by the OPE backbones through modest inductive effects. Interestingly, sizable third-order nonlinear optical (NLO) responses (gamma) and enhanced two-photon absorption (TPA) cross-sections (sigma((2))) were determined for the multifullerene-OPE hybrid 31 relative to its OPE precursor from differential optical Kerr effect (DOKE) experiments. Such enhanced NLO performance is presumably due to the occurrence of periconjugation and/or charge transfer effects in the excited state. In addition, comparatively strong excited-state absorption was observed and characterized for OPE pentamer 12. Thus, the use of such fullerene-derivatized conjugated oligomers aids the quest for molecules with large third-order NLO and TPA properties.

Donor/Acceptor Effects on the Linear and Nonlinear Optical Properties of Geminal Diethynylethenes (g‐DEEs)

“…of MPPBT in DMSO [27]. The ultrafast TPA cross-section of the sample is then calibrated to that of the reference sample (s (2) MPPBT ¼ 380 GM; l ¼ 800 nm) according to [30]: DFT and NBO Analyses. The full geometry optimizations of 18a -e were performed by using the density-functional-theory (DFT) approach, in which Becke three-parameters Lee-Yang-Parr (B3LYP) hybrid functional was employed together with the 6-31G* basis set [38].…”

“…It can also be noted that the largest g-value observed in the current study -that of D -A g-DEE 11 -is likely higher than that of D -A g-DEEs 8 and 5 because 11 possesses a longer linearlyconjugated p-delocalization, due to the pendent phenyl rings. In addition to the measurement of g, the DOKE setup used in this study also allows for the concurrent assessment of the two-photon-absorption (TPA) cross-section (s (2) ) of the samples under study at 800 nm [30]. Several samples, i.e., 5 and 9 -11, were therefore examined, and, while modest, the TPA cross-section does show an increase in s (2) from 6 to 12 GM upon changing from an acceptor (see 9) to a donor g-DEE (see 10), and a further increase in s (2) to 22 GM is found for the D -A g-DEE 11.…”

Fullerene‐Derivatized Amino Acids: Synthesis, Characterization, Antioxidant Properties, and Solid‐Phase Peptide Synthesis

“…A general description of the NMR probes and methodology used has been previously reported. [33] Baa (1 a N-Ac-C 60 -Phe-OMe (N-Ac-Baa-OMe): Prepared as previously reported. [14] Yield: 43 %.…”

Fulereno[C60]: química e aplicações

“…Vários outros exemplos de aplicação de derivados fulerênicos em óptica não linear podem ser encontrados na literatura destacando-se a síntese de C 60 -tetratiafulvalenos, 106 de fulerodendrímeros 107 e de C 60 -oligo-p-fenilenoetinileno, 108 dentre outros.…”