Excited-State Carrier Dynamics in Semiconducting Heterostructures from Self-Sorted NIR Active Dyes.

Heterostructures comprise two or more different semiconducting materials stacked either as co-assemblies or self-sorted based on their dynamics of aggregates. However, self-sorting in heterostructures is rather significant in improving the short exciton diffusion length and charge separation. Despite small organic molecules being known for their self-sorting nature, macrocyclic are hitherto unknown owing to unrestrained assemblies from extended π-conjugated systems.

Pyrene Derived Donor-Acceptor as a Host for Fullerene Unveils the Crystallinity in Semiconducting Nanostructures.

Donor-acceptor in linear π-conjugated systems elicits the intramolecular charge transfer which improves the optical and electronic characteristics. Nevertheless, linear arrangement of electron donor and acceptor finely tune the charge or electron transfer process divulges the device performance. Therefore, molecular engineering of appropriate D-A with precise spacer is indeed challenging.

Cross-conjugated vinylogous annulation of π-CF-allyl Pd-complexes with 4-methyl-3-trifluoroacetyl-quinolones.

Herein, we disclose the hitherto unknown cross-conjugated vinylogous annulation of π-CF-allyl Pd complexes with 4-methyl-3-trifluoroacetyl-quinolones to access phenanthridones. The CF group in the Pd-π-allyl complex is key for exclusive γ-regioselectivity and further annulation. The solvent switch orchestrates the dihydro-phenanthridones (CHCN) and hydroxy-phenanthridones (DMF) in good yields, and also showed excellent optoelectronic properties.

Hot carrier dynamics in metalated porphyrin-naphthalimide thin films.

This study employs femtosecond transient absorption spectroscopy to investigate the rapid dynamics of excited state carriers in three metalated porphyrin-naphthalimide (PN) molecules and one free-base molecule. The dynamics of electron injection, from PN to mesoporous titania (TiO), in PN adsorbed TiO films (Ti-PN), were carefully investigated and compared to PN adsorbed ZrO films (Zr-PN). In addition, we examined the self-assembled PN films and found that, in their self-assembled state, these molecules exhibited a longer relaxation time than Zr-PN monomeric films, where the charge injection channel was insignificant.

Excited Charge Separation in a π-Interacting Phenothiazine-Zinc Porphyrin-Fullerene Donor-Acceptor Conjugate.

We have designed, synthesized, and characterized a donor-acceptor triad, , that consists of a π-interacting phenothiazine-linked porphyrin as a donor and sensitizer and fullerene as an acceptor to seek charge separation upon photoexcitation. The optical absorption spectrum revealed red-shifted Soret and Q-bands of porphyrin due to charge transfer-type interactions involving the two ethynyl bridges carrying electron-rich and electron-poor substituents. The redox properties suggested that the phenothiazine-porphyrin part of the molecule is easier to oxidize and the fullerene part is easier to reduce.