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Fourteen substituted diketopyrrolopyrrole (DPP) molecules in a donor (D)–acceptor (DPP)–donor (D) arrangement were designed. We employed density functional theory, time‐dependent DFT, DFT‐MRCI and the ab initio wave function second‐order algebraic diagrammatic construction (ADC(2)) methods to investigate theoretically these systems. The examined aromatic substituents have one, two, or three hetero‐ and non‐hetero rings. We comprehensively investigated their optical, electronic, and charge transport properties to evaluate potential applications in organic electronic devices. We found that the donor substituents based on one, two, or three aromatic rings bonded to the DPP core can improve the efficiency of an organic solar cell by fine‐tuning the highest occupied molecular orbital/lowest unoccupied molecular orbital levels to match acceptors in typical bulk heterojunctions acceptors. Several properties of interest for organic photovoltaic devices were computed. We show that the investigated molecules are promising for applications as donor materials when combined with typical acceptors in bulk heterojunctions because they have appreciable energy conversion efficiencies resulting from their low ionization potentials and high electron affinities. This scenario allows a more effective charge separation and reduces the recombination rates. A comprehensive charge transfer analysis shows that D–A (DDP)–D systems have significant intramolecular charge transfer, further confirming their promise as candidates for donor materials in solar cells. The significant photophysical properties of DPP derivatives, including the high fluorescence emission, also allow these materials to be used in organic light‐emitting diodes. [ABSTRACT FROM AUTHOR]

The alternant polycyclic aromatic hydrocarbon pyrene has photophysical properties that can be tuned with different donor and acceptor substituents. Recently, a D (donor)‐Pyrene (bridge)‐A (acceptor) system, DPA, with the electron donor N,N‐dimethylaniline (DMA), and the electron acceptor trifluoromethylphenyl (TFM), was investigated by means of time‐resolved spectroscopic measurements (J. Phys. Chem. Lett. 2021, 12, 2226–2231). DPA shows great promise for potential applications in organic electronic devices. In this work, we used the ab initio second‐order algebraic diagrammatic construction method ADC(2) to investigate the excited‐state properties of a series of analogous DPA systems, including the originally synthesized DPAs. The additionally investigated substituents were amino, fluorine, and methoxy as donors and nitrile and nitro groups as acceptors. The focus of this work was on characterizing the lowest excited singlet states regarding charge transfer (CT) and local excitation (LE) characters. For the DMA‐pyrene‐TFM system, the ADC(2) calculations show two initial electronic states relevant for interpreting the photodynamics. The bright S1 state is locally excited within the pyrene moiety, and an S2 state is localized ~0.5 eV above S1 and characterized as a donor to pyrene CT state. HOMO and LUMO energies were employed to assess the efficiency of the DPA compounds for organic photovoltaics (OPVs). HOMO‐LUMO and optical gaps were used to estimate power conversion and light‐harvesting efficiencies for practical applications in organic solar cells. Considering the systems using smaller D/A substituents, compounds with the strong acceptor NO2 substituent group show enhanced CT and promising properties for use in OPVs. Some of the other compounds with small substituents are also found to be competitive in this regard. [ABSTRACT FROM AUTHOR]

A classical methodology to design free‐base meso‐tetra‐(1‐pyrenyl)porphyrin (H2TPyrP) and their corresponding metalloporphyrins containing Zn(II), Cu(II), Ni(II), Co(III), and Mn(III) was described. These porphyrins were characterized in terms of structure, photophysical, and interactions profile with calf‐thymus deoxyribonucleic acid (CT‐DNA) and bovine serum albumin (BSA). H2TPyrP exhibited five characteristic bands in the visible wavelength: Soret (432 nm) and Q‐bands (520–650 nm range), while the metalloporphyrins showed some spectrum shifts according to the nature of the ion, which were also explored by time‐dependent density functional theory (TD‐DFT) calculations. The fluorescence and singlet oxygen quantum yield (Φfl, ΦΔ, respectively) decreased with the presence of metal species in the porphyrin core. The porphyrins interact spontaneously via a ground‐state association in the minor groove of CT‐DNA following the increasing order of binding: CuTPyrP

The presence of metal species in the porphyrin core influences the ground and excited states. Biomolecule interaction experiments show that these porphyrins interact spontaneously in the minor groove of CT-DNA and in subdomain IB in the BSA pocket. Front Cover: Synthesis, Photophysics, Computational Approaches, and Biomolecule Interactive Studies of Metalloporphyrins Containing Pyrenyl Units: Influence of the Metal Center (Eur. J. Inorg. [Extracted from the article]