High LUMO energy level C60(OCH3)4 derivatives:Electronic acceptors for photovoltaiccellswithhigheropen-circuitvoltage

E-mail Addresses: [email protected] regioselective C-60(OCH3)(4) derivatives, C-60(OCH3)(4)-PCBM (a methanofullerene derivative of C-60(OCH3)(4), PCBM=[6,6]-phenyl-C-61-butyric acid methyl ester) and C-60(OCH3)(4)-APCBM (an aziridinofullerene derivative of C-60(OCH3)(4)) were synthesized from C60Cl6 and used as acceptor for polymer solar cells. Revealed by cyclic voltammetry, the LUMO energy levels of C-60(OCH3)4-APCBM and C-60(OCH3)(4)-PCBM are 0.2 and 0.3 eV higher than that of PCBM, respectively. For the polymer photovoltaic cells with fullerene (PCBM, C-60(OCH3)(4)-APCBM or C-60(OCH3)(4)-PCBM) acceptor in combination with poly(3-hexylthiophene) (P3HT) donor, the open-circuit voltage is increased from 0.58 V (for PCBM) to 0.63 V (for C-60(OCH3)(4)-APCBm) and 0.72 V (for C-60(OCH3)(4)-PCBM). The higher open-circuit voltages are reasonably attributed to the higher LUMO levels of the C-60(OCH3)(4) derivatives because of four electron-donating methoxy groups attached. The photovoltaic performance of C-60(OCH3)(4)-PCBMbased device is higher than that involving C-60(OCH3)(4)-APCBM, largely due to the structural changeability of C-60(OCH3)(4)-APCBM resulting from the rotatable N-C bond bridge therein. This work demonstrates that fullerene derivatives with higher LUMO level can be functionalized from multiaddition of electron-donating groups, and exemplifies that photovoltaic performances of fullerene-based solar cells are sensitive even to trivial bridge between functional group and fullerene core. (C) 2012 Elsevier B.V. All rights reserved .National Nature Science Foundation of China U1205111 21031004 21021061 J1210014 20923004 National Basic Research 973 Program of China 2011CB93590

Dissipation Behavior, Residue, and Risk Assessment of Benziothiazolinone in Apples

Benziothiazolinone is the first independently developed fungicide in China. It has been used to effectively control fungal diseases in a variety of fruits, vegetables, and crops. In this study, the degradation behavior and final residue of benziothiazolinone in apples is discussed, and the dietary risk to consumers was evaluated. High-performance liquid chromatography–tandem mass spectrometry (LC-MS/MS) was used to determine benziothiazolinone residues in apple samples from eight different regions of China. The average recovery of benziothiazolinone in apples was 85.5–100.2%, and the relative standard deviation (RSD) was 0.8–14.9%. The limits of the method of quantification of benziothiazolinone in apples was 0.01 mg/kg. Under good agricultural practices (GAP) conditions, the final residues of benziothiazolinone in apples were below 0.01 mg/kg, lower than the maximum residual limit (MRL) of China. Although the degradation half-lives of benziothiazolinone were 23.9 d–33.0 d, the risk quotient (RQ) of benziothiazolinone was 15.5% by calculating the national estimated daily intake and comparing it with the acceptable daily intake. These results suggested that under GAP conditions, the intake of benziothiazolinone from apples exhibits an acceptably low health risk on consumers