High-Throughput Screening Approach for the Optoelectronic Properties of Conjugated Polymers

We propose a general high-throughput virtual screening approach for the optical and electronic properties of conjugated polymers. This approach makes use of the recently developed xTB family of low-computational-cost density functional tight-binding methods from Grimme and co-workers, calibrated here to (Time-Dependent) Density Functional Theory ((TD)­DFT) data computed for a representative diverse set of (co)­polymers. Parameters drawn from the resulting calibration using a linear model can then be applied to the xTB derived results for new polymers, thus generating near DFT-quality data with orders of magnitude reduction in computational cost. As a result, after an initial computational investment for calibration, this approach can be used to quickly and accurately screen on the order of thousands of polymers for target applications. We also demonstrate that the (opto)­electronic properties of the conjugated polymers show only a very minor variation when considering different conformers and that the results of high-throughput screening are therefore expected to be relatively insensitive with respect to the conformer search methodology applied

High-Throughput Screening Approach for the Optoelectronic Properties of Conjugated Polymers

We propose a general high-throughput virtual screening approach for the optical and electronic properties of conjugated polymers. This approach makes use of the recently developed xTB family of low-computational-cost density functional tight-binding methods from Grimme and co-workers, calibrated here to (Time-Dependent) Density Functional Theory ((TD)­DFT) data computed for a representative diverse set of (co)­polymers. Parameters drawn from the resulting calibration using a linear model can then be applied to the xTB derived results for new polymers, thus generating near DFT-quality data with orders of magnitude reduction in computational cost. As a result, after an initial computational investment for calibration, this approach can be used to quickly and accurately screen on the order of thousands of polymers for target applications. We also demonstrate that the (opto)­electronic properties of the conjugated polymers show only a very minor variation when considering different conformers and that the results of high-throughput screening are therefore expected to be relatively insensitive with respect to the conformer search methodology applied

Photocatalytic Hydrogen Evolution from Water Using Fluorene and Dibenzothiophene Sulfone-Conjugated Microporous and Linear Polymers

Three series of conjugated microporous polymers (CMPs) were studied as photocatalysts for hydrogen production from water using a sacrificial hole scavenger. In all cases, dibenzo­[b,d]­thiophene sulfone polymers outperformed their fluorene analogues. A porous network, S-CMP3, showed the highest hydrogen evolution rates of 6076 μmol h–1 g–1 (λ > 295 nm) and 3106 μmol h–1 g–1 (λ > 420 nm), with an external quantum efficiency of 13.2% at 420 nm. S-CMP3 outperforms its linear structural analogue, P35, whereas in other cases, nonporous linear polymers are superior to equivalent porous networks. This suggests that microporosity might be beneficial for sacrificial photocatalytic hydrogen evolution, if suitable linkers are used that do not limit charge transport and the material can be wetted by water as studied here by water sorption and quasi-elastic neutron scattering

Electron Storage System Based on a Two-Way Inversion of Redox Potentials

Molecular-level multielectron handling toward electrical storage is a worthwhile approach to solar energy harvesting. Here, a strategy which uses chemical bonds as electron reservoirs is introduced to demonstrate the new concept of “structronics” (a neologism derived from “structure” and “electronics”). Through this concept, we establish, synthesize, and thoroughly study two multicomponent “super-electrophores”: 1,8-dipyridyliumnaphthalene, 2, and its N,N-bridged cyclophane-like analogue, 3. Within both of them, a covalent bond can be formed and subsequently broken electrochemically. These superelectrophores are based on two electrophoric (pyridinium) units that are, on purpose, spatially arranged by a naphthalene scaffold. A key characteristic of 2 and 3 is that they possess a LUMO that develops through space as the result of the interaction between the closely positioned electrophoric units. In the context of electron storage, this “super-LUMO” serves as an empty reservoir, which can be filled by a two-electron reduction, giving rise to an elongated C–C bond or “super-HOMO”. Because of its weakened nature, this bond can undergo an electrochemically driven cleavage at a significantly more anodicyet accessiblepotential, thereby restoring the availability of the electron pair (reservoir emptying). In the representative case study of 2, an inversion of potential in both of the two-electron processes of bond formation and bond-cleavage is demonstrated. Overall, the structronic function is characterized by an electrochemical hysteresis and a chemical reversibility. This structronic superelectrophore can be viewed as the three-dimensional counterpart of benchmark methyl viologen (MV)

Electron Storage System Based on a Two-Way Inversion of Redox Potentials

Molecular-level multielectron handling toward electrical storage is a worthwhile approach to solar energy harvesting. Here, a strategy which uses chemical bonds as electron reservoirs is introduced to demonstrate the new concept of “structronics” (a neologism derived from “structure” and “electronics”). Through this concept, we establish, synthesize, and thoroughly study two multicomponent “super-electrophores”: 1,8-dipyridyliumnaphthalene, 2, and its N,N-bridged cyclophane-like analogue, 3. Within both of them, a covalent bond can be formed and subsequently broken electrochemically. These superelectrophores are based on two electrophoric (pyridinium) units that are, on purpose, spatially arranged by a naphthalene scaffold. A key characteristic of 2 and 3 is that they possess a LUMO that develops through space as the result of the interaction between the closely positioned electrophoric units. In the context of electron storage, this “super-LUMO” serves as an empty reservoir, which can be filled by a two-electron reduction, giving rise to an elongated C–C bond or “super-HOMO”. Because of its weakened nature, this bond can undergo an electrochemically driven cleavage at a significantly more anodicyet accessiblepotential, thereby restoring the availability of the electron pair (reservoir emptying). In the representative case study of 2, an inversion of potential in both of the two-electron processes of bond formation and bond-cleavage is demonstrated. Overall, the structronic function is characterized by an electrochemical hysteresis and a chemical reversibility. This structronic superelectrophore can be viewed as the three-dimensional counterpart of benchmark methyl viologen (MV)

Electron Storage System Based on a Two-Way Inversion of Redox Potentials

Molecular-level multielectron handling toward electrical storage is a worthwhile approach to solar energy harvesting. Here, a strategy which uses chemical bonds as electron reservoirs is introduced to demonstrate the new concept of “structronics” (a neologism derived from “structure” and “electronics”). Through this concept, we establish, synthesize, and thoroughly study two multicomponent “super-electrophores”: 1,8-dipyridyliumnaphthalene, 2, and its N,N-bridged cyclophane-like analogue, 3. Within both of them, a covalent bond can be formed and subsequently broken electrochemically. These superelectrophores are based on two electrophoric (pyridinium) units that are, on purpose, spatially arranged by a naphthalene scaffold. A key characteristic of 2 and 3 is that they possess a LUMO that develops through space as the result of the interaction between the closely positioned electrophoric units. In the context of electron storage, this “super-LUMO” serves as an empty reservoir, which can be filled by a two-electron reduction, giving rise to an elongated C–C bond or “super-HOMO”. Because of its weakened nature, this bond can undergo an electrochemically driven cleavage at a significantly more anodicyet accessiblepotential, thereby restoring the availability of the electron pair (reservoir emptying). In the representative case study of 2, an inversion of potential in both of the two-electron processes of bond formation and bond-cleavage is demonstrated. Overall, the structronic function is characterized by an electrochemical hysteresis and a chemical reversibility. This structronic superelectrophore can be viewed as the three-dimensional counterpart of benchmark methyl viologen (MV)