Louzhen Fan

Photoconductivity of [60]fullerene derivative doped PVK

1,2-(1′, 1′,2′,2′-tetracyanomethanoxymethano) [60] fullerene has been synthesized. It exhibits stronger ability of accepting electron than pure [60]fullerene. A film of PVK doped with 1.6% by weight of this C60-derivative was prepared and characterized. The measured photoinduced discharge curves and the photoconductivity spectra of the film demonstrate that the photoconductivity of PVK doped with this [60]fullerene derivative is higher than that of PVK doped with pure C60.

Synthesis and properties of an organo-[C60]fullerene-containing PPV unit

Abstract A novel PPV-[C60] dyad which was partly soluble in common organic solvent was synthesized via the cycloaddition reaction of azide group with [C60]fullerene. Copolymer PPV-[C60] was isolated in up to 70% yields with molecular weights ranging up to 3615 relative to polystyrene standards. Cyclic voltammeter (CV) analysis for the copolymers showed three reversible waves. UV–VIS and fluorescence spectra of the copolymer were also studied.

New electron donor: bis(ethylenedithio)tetrathiafulvalene derivative with four hydroxyl groups

New electron donor ET (bis(ethylenedithio)tetrathiafulvalene) derivative with four hydroxyl groups was synthesized and characterized. Its redox potentials were measured with cyclic voltammetry, and the comparison with ET and its analogue in this respect was made. These results indicated that this new electron donor possessed similar electron-donating properties as ET. Moreover, preliminary results of theoretical calculation for this new donor molecule were also presented.

Synthesis and Electrochemical Studies of Novel Electron Donors—BEDT-TTF Fused with p-Dimethoxybenzene and Hydroquinone

Abstract Novel electron donors — BEDT-TTF fused with p-dimethoxybenzene and hydroquinone were synthesized and characterized with elemental analysis, IR, 1H-NMR and MS spectra. Their redox potential were determined with cyclic voltammetry, and compared with those of BEDT-TTF.

Positive shifts of the C60 reduction potentials by introducing cyano groups

Abstract The electrochemical properties of a new C60 derivative with a tetracyanotetrahydrofuran addend were investigated by cyclic voltammetry. Its reduction potentials were measured in several solution with different solvents. It was found that the first reduction of the derivative shifted positively by 170 mV compared with that of C60, reflecting its stronger electron-accepting ability. The NIR characteristic absorption bands of its monoanion and dianion were also obtained.

Photovoltaic properties of MEH-PPV doped with new methanofullerene derivatives

The photophysical and photovoltaic properties of MEH-PPV doped with two new mono-methanofullerenes were studied systematically. The different quenching of the luminescence of MEH-PPV by the two methanofullerenes is corresponding to the photovoltaic performances of the blends, which suggested that the photovoltaic properties of bulk heterojunction polymer photovoltaic devices could be improved by the select doping of fullerene derivatives.

Effect of Substituents on the Redox Potentials of C60 Derivatives

Abstract The electrochemical properties of four C60 derivatives (compounds 1∼4) were investigated with cyclic voltammetry (CV), and compared with that of C60. The reduction potentials of compound 1∼3 shifted to more negative positions than C60, and their oxidation peaks appeared at the lower potentials. Significantly, the reduction potentials of compound 4 shifted to more positive positions than C60, which is advantageous to form charge-transfer complexes with more donors. So the reduction properties in different solvents and in situ NIR absorption spectra of compound 4 were studied in more details. In addition, the AM1 molecular orbital calculation was performed on C60 and compound 1∼4 for the explanation of the potential shifts. The reduction potentials of these compounds exhibited good linear relationships with the calculation LUMO or LUMO+1 energy levels.

A novel electron donor containing 16 sulfur atoms with extended and cross-conjugated structure-synthesis, crystal structure and electrochemical studies

A novel electron donor 2 with extended and cross-conjugated structure was synthesized and characterized. Its redox potentials and crystal structure were determined and analyzed. An unexpected product 7 from the thermal decomposition of 2 was also detected and preliminarily characterized.

Photoconductivity of [60]fullerene derivatives

Two [60]fullerene derivatives (compounds 1 and 2) have been synthesized. Their redox properties have been measured by cyclic voltammetry. The photoconductivities of poly(N-vinylcarbazole) (PVK) doped with [60] fullerene and with their derivatives have been studied to explore the possible relationship between the reductibility of fullerenes and the photoconductivity of fullerenes-doped PVK. The charge generation efficiencies of PVK doped with [60]fullerene and with its derivatives have changed remarkably: the diversity of charge generation efficiency is obvious in different doping systems. The result indicates that there is charge transfer between fullerenes and PVK.

Effect of Solvents and Supporting Electrolytes on the Electrochemical Properties of C70 and its Comparison with C60

Abstract Surrounding medium effect on the electrochemical properties of C70 was studied in 9 single, 2 mixture solvents and 7 supporting electrolytes by cyclic. voltammetry in the temperature range between 260 and 288K. The obtained results were analyzed and compared with those of C60. It was shown that, due to the different structure between C70 and C60, the degree of these medium effect on their reduction potential was different. The solvent effect on the reduction of C70 was more significant than that of C60; on the other hand, the solvophobic interaction between the larger cations of supporting electrolyte and C70 anions was weaker than that between the same cations and C60 anions. In addition, C70 redox couple showed better reversibility when the supporting electrolyte contains larger cations. C70 redox potentials were also measured as a function of temperature, and the entropy changes of C70reduction were calculated.