A series of porphyrin sensitizers that featured two electron-donating groups and dual anchoring groups that were connected through a porphine π-bridging unit have been synthesized and successfully applied in dye-sensitized solar cells (DSSCs). The presence of electron-donating groups had a significant influence on their spectroscopic, electrochemical, and photovoltaic properties. Overall, the dual anchoring groups gave tunable electronic properties and stronger attachment to TiO2 . These new dyes were readily synthesized in a minimum number of steps in gram-scale quantities. Optical and electrochemical data confirmed the advantages of these dyes for use as sensitizers in DSSCs. Porphyrins with electron-donating amino moieties provided improved charge separation and better charge-injection efficiencies for the studied dual-push-pull dyes. Attenuated total reflectance-Fourier-transform infrared (ATR-FTIR) and X-ray photoelectron spectroscopy of the porphyrin dyes on TiO2 suggest that both p-carboxyphenyl groups are attached onto TiO2, thereby resulting in strong attachment. Among these dyes, cis-Zn2BC2A, with two electron-donating 3,6-ditertbutyl-phenyl-carbazole groups and dual-anchoring p-carboxyphenyl groups, showed the highest efficiency of 4.07 %, with J(SC)=9.81 mA cm(-2), V(OC)=0.63 V, and FF=66 %. Our results also indicated a better photostability of the studied dual-anchored sensitizers compared to their mono-anchored analogues under identical conditions. These results provide insight into the developments of a new generation of high-efficiency and thermally stable porphyrin sensitizers.

An efficient, one-pot method for the synthesis of dibenzodiazepinone derivatives involving copper-catalyzed tandem C À N bond formation is reported. The use of various halo amide and 2-iodoaniline derivatives permitted the synthesis of an array of dibenzodiazepinone derivatives in moderate to good yields. Moreover, a dibenzodiazepinone derivative {2-(

The unusual alcohol mediated formation of 4-oxo-2-aryl-4H-chromene-3-carboxylate (flavone-3-carboxylate) derivatives from 4-hydroxycoumarins and β-nitroalkenes in an alcoholic medium is described. The transformation occurs via the in situ formation of a Michael adduct, followed by the alkoxide ion mediated rearrangement of the intermediate. The effect of the different alcohol and nonalcohol media on the reaction was investigated.

Abstract:The synthesis of iodo-substituted tetracyclic indole fused azulene derivatives was achieved from the reaction of 2-(substituted phenylethynyl)-benzaldehydes and different indoles in the presence of molecular iodine. The reaction involves the formation of a bisindole from the corresponding 2-(substituted phenylethynyl)benzaldehyde and indole followed by iodocyclization in a one-pot cascade process. A wide range of 2-(substituted phenylethynyl)-benzaldehydes and indoles were utilized in this protocol to derive a diverse range of iodo-substituted tetracyclic indole fused azulene derivatives in moderate to good yields. Further functionalizations of the iodo-substituted tetracyclic indole fused azulenes were achieved by various palladium-catalyzed crosscoupling reactions to generate highly substituted tetracyclic indole fused azulene derivatives.

An efficient FeCl3 catalyzed protocol for the synthesis of amino functionalized indolylnitroalkanes from easily available precursor indolylnitroalkenes and substituted amines has been developed. Regioselective C-alkylation in the presence of free amino substituted arenes occurred. The scope of this methodology shows good functional group tolerance, and further, this protocol was used to prepare indolylquinoline derivatives.