Designing New Indene-Fullerene Derivatives as Electron-Transporting Materials for Flexible Perovskite Solar Cells.

The synthesis and characterization of a family of indene-C60 adducts obtained via Diels-Alder cycloaddition [4 + 2] are reported. The new C60 derivatives include indenes with a variety of functional groups. These adducts show lowest unoccupied molecular orbital energy levels to be at the right position to consider these compounds as electron-transporting materials for planar heterojunction perovskite solar cells. Selected derivatives were applied into inverted (p-i-n configuration) perovskite device architectures, fabricated on flexible polymer substrates, with large active areas (1 cm2). The highest power conversion efficiency, reaching 13.61%, was obtained for the 6'-acetamido-1',4'-dihydro-naphtho[2',3':1,2][5,6]fullerene-C60 (NHAc-ICMA). Spectroscopic characterization was applied to visualize possible passivation effects of the perovskite's surface induced by these adducts.

Synthesis of Selectively Substituted or Deuterated Indenes via Sequential Pd and Ru Catalysis.

A strategy for the synthesis of functionalized indenes is presented. The readily available substituted phenols are used as starting materials in the reaction sequence composed of Pd-catalyzed Suzuki coupling and Ru-catalyzed ring-closing metathesis, thus representing a practical method for the controlled construction of functionalized indene derivatives. The methodology has been successfully applied to a broad range of substrates, producing substituted indenes in excellent yields. This approach is also utilized for the synthesis of substituted indenes selectively deuterated in position 3, which are rare in literature.

Magnetic behaviour of TbPc2 single-molecule magnets chemically grafted on silicon surface.

Single-molecule magnets (SMMs) are among the most promising molecular systems for the development of novel molecular electronics based on spin transport. Going beyond investigations focused on physisorbed SMMs, in this work the robust grafting of terbium(III) bis(phthalocyaninato) complexes to a silicon surface from a diluted solution is achieved by rational chemical design yielding the formation of a partially oriented monolayer on the conducting substrate. Here by exploiting the surface sensitivity of X-ray circular magnetic dichroism, we evidence an enhancement of the magnetic bistability of this SMM, in contrast to the dramatic reduction of the magnetic hysteresis that characterizes monolayer deposits evaporated on noble and ferromagnetic metals. Photoelectron spectroscopy investigations and density functional theory analysis suggest a non-innocent role played by the silicon substrate, evidencing the potentiality of this approach for robust integration of bistable magnetic molecules in electronic devices.