Impact of Precatalyst Activation on Suzuki-Miyaura Catalyst-Transfer Polymerizations: New Mechanistic Scenarios for Pre-transmetalation Events

The relevance of L_nPdX₂ precatalyst activation on the Suzuki-Miyaura reaction course was investigated in the case of catalyst-transfer polymerizations. A catalytic study, backed up by theoretical calculations, allowed to ascertain the coexistence of a neutral and an anionic mechanistic pathways in the precatalyst activation, in which the bulky ^<i>t</i>Bu₃P external ligand plays a crucial role. The fine-tuning of the catalytic conditions can steer the activation step toward the anionic pathway, leading to the full control over the polymerization course. While providing insights and perspectives into the catalyst-transfer polymerizations, these results uncover unexplored scenarios for the pre-transmetalation events of Suzuki-Miyaura reactions contributing to its full understanding

Sustainability of Organic Dye-Sensitized Solar Cells: The Role of Chemical Synthesis

The synthesis of a novel and efficient π-extended D-A-π-A organic sensitizer (<b>G3</b>, η = 8.64%) for dye-sensitized solar cells has been accomplished by applying the green chemistry pillars, aiming at overriding traditional routes involving organometallic intermediates with innovative synthetic strategies for reducing the waste burden and dye production costs. It has been demonstrated that the obtainment of a complex target sensitizer can be exclusively pursued via direct arylation reactions. Green metrics comparison with those of a traditional synthetic pathway clearly indicates that the new approach has a lower environmental impact in terms of chemical procedures and generated wastes, stressing the importance of the synergy between the molecular design and the synthetic plan in the framework of environmentally friendly routes to back up sustainable development of third-generation photovoltaics. Additionally, the stability of the <b>G3</b>-based photovoltaic devices was also investigated in aging tests on large area devices, evidencing the excellent potentialities of the proposed structure for all practical applications involving inorganic semiconductor/organic dye interfaces

Addressing the Function of Easily Synthesized Hole Transporters in Direct and Inverted Perovskite Solar Cells

Two simple small molecules are designed and successfully implemented here as hole-transporting material (HTM) in perovskite-based solar cells (PSCs). With the aim of elucidating the interconnection between molecular structure, properties, and their role in the working devices, these HTMs are implemented in both thin planar direct (n–i–p) and inverse (p–i–n) geometries. It is observed how the HTM layer morphology influences the photovoltaic performance. Moreover, from analysis of the different devices, fundamental information is retrieved on the factors influencing small molecule hole extracting/transporting functionality in PSCs. Specifically, two main roles are identified: When HTMs are introduced as growing substrate (p–i–n), there is a positive impact on the device performance via influence of perovskite formation; meanwhile, their efficacy in transporting the holes governs the performance of direct configurations (n–i–p). These findings can be extended to a wide family of small molecule HTMs, providing general rules for refining the design of novel and more efficient ones