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The Rb0.94Mn0.94Co0.06[Fe(CN)6]0.98 material was designed to exhibit a 75 K wide thermal hysteresis around room temperature, associated with a bistability between the low temperature MnIIIFeII tetragonal phase and the high temperature MnIIFeIII cubic phase. We have recently shown that a single laser pulse can be used to drive, at room temperature, the photoinduced phase transition from the MnIIIFeII tetragonal phase to the MnIIFeIII cubic phase. By using a specific powder sample streaming technique, we could monitor by time‐resolved X‐ray diffraction how the ultrafast out‐of‐equilibrium dynamics, imposed by the structural relaxation around the local photoinduced charge transfer, changes with the fluence of the laser pulse. In this paper we present a detailed structural analysis of the crystalline reorganizations associated with the charge‐transfer in different regimes of photoexcitation. In the low excitation polaronic regime, the photoinduced charge transfer is local and accompanied by an anisotropic distortion of the Mn coordination sphere and of the tetragonal lattice. In the high excitation regime, a macroscopic and cooperative charge‐transfer phase transition occurs towards the cubic lattice, where the coordination around the Mn reaches octahedral symmetry. [ABSTRACT FROM AUTHOR]

Ag3BiI6 (ABI) is one of the most widely explored lead‐free perovskite‐inspired materials for eco‐friendly solar cell applications. However, despite the intense research efforts, the photovoltaic performance of ABI‐based devices remains very modest, primarily due to poor film morphology and ineffective charge extraction. This work aims at investigating the potential benefits of a thermally evaporated cesium iodide (CsI) interlayer on the performance of ABI‐based solar cells. Upon the addition of CsI atop the ABI layer in the device stack, the solar cells deliver a power conversion efficiency (PCE) of 2.27%. This is the highest efficiency reported for ABI solar cells employing a similar device architecture. It is found that the enhancement in PCE is largely due to improvement in the ABI|hole transport layer interface upon the introduction of CsI interlayer. The improvement is largely ascribed to enhanced surface coverage upon introduction of CsI interlayer, as evidenced by our comprehensive microscopy studies. Furthermore, impedance spectroscopy analysis is employed to provide further insights into the changes in charge transfer dynamics interlayer that dictate the enhancement of fill factor and short‐circuit current density in the devices. The findings indicate that the addition of CsI promotes charge transfer and minimizes recombination losses. [ABSTRACT FROM AUTHOR]

The future application of Li metal batteries (LMBs) at scale demands electrolytes that endow improved performance under fast-charging and low-temperature operating conditions. Recent works indicate that desolvation kinetics of Li+ plays a crucial role in enabling such behavior. However, the modulation of this process has typically been achieved through inducing qualitative degrees of ion pairing into the system. In this work, we find that a more quantitative control of the ion pairing is crucial to minimizing the desolvation penalty at the electrified interface and thus the reversibility of the Li metal anode under kinetic strain. This effect is demonstrated in localized electrolytes based on strongly and weakly bound ether solvents that allow for the deconvolution of solvation chemistry and structure. Unexpectedly, we find that maximum degrees of ion pairing are suboptimal for ultralow temperature and high-rate operation and that reversibility is substantially improved via slight local dilution away from the saturation point. Further, we find that at the optimum degree of ion pairing for each system, weakly bound solvents still produce superior behavior. The impact of these structure and chemistry effects on charge transfer are then explicitly resolved via experimental and computational analyses. Lastly, we demonstrate that the locally optimized diethyl ether-based localized-high-concentration electrolytes supports kinetic strained operating conditions, including cycling down to -60 °C and 20-min fast charging in LMB full cells. This work demonstrates that explicit, quantitative optimization of the Li+ solvation state is necessary for developing LMB electrolytes capable of low-temperature and high-rate operation.

We present a significant advancement in the synthesis of carbon nitride framework (CN) using a rapid electric bunsen burner (EBB) method, achieving notable outcomes within a mere 10-min timeframe. The resulting material, designated as U10, exhibits amplified porosity and a semi-scrolling structure with a thickness measuring at 2.1 nm. In comparison to conventionally synthesized urea-derived carbon nitride (UCN) through a box furnace, the U10 demonstrates significantly heightened photocatalytic activity in both hydrogen (H 2) production and the removal of organic dye (methylene blue) from aqueous solutions. To ensure the robustness and reliability of this synthetic approach, two additional precursors were subjected to testing, and their rates of H 2 production were analyzed. The exceptional photocatalytic performance of the U10 material arises from its distinctive structural attributes and the synergistic influences of oxygen doping (O-doping) and the cyano (-CΞN) functional group, which are introduced during the rapid synthesis strategy. This innovative and streamlined strategy for synthesizing CN not only conserves energy and time but also significantly reduces production costs, rendering it a feasible method for the large-scale production of carbon nitride material. [Display omitted] • Developed a fast synthesis of defect-rich CN using a controlled EBB method. • Identified defect-rich CN with -CΞN groups and O, enhancing charge dynamics. • Improved charge transfer and electron-hole lifespan shown by light-dependent EPR. • Calculated thermodynamically stable structure using first-principle calculations. • Tracked intermediate products in fast CN synthesis initiated by urea. [ABSTRACT FROM AUTHOR]

Panchromatic dyes have been highly useful in the realm of optical devices. Here, we report that panchromatic dyes with heterohelicenes have been successfully synthesized using a donor‐acceptor strategy. Our synthesis resulted in the creation of π‐extended aza[5]helicene oligomers with butadiyne linkages, which displayed bathochromically shifted absorption and emission spectra. The solvent‐dependent optical measurements revealed the intramolecular charge transfer characteristic of these molecules, and theoretical calculations described the biased molecular orbitals on the azahelicene units that generated the charge‐transfer characteristic. Encouraged by these results, we also prepared donor‐acceptor‐donor dyads using azahelicenes and dimide derivatives, resulting in panchromatic absorbing characteristics covering the range from 250 nm to 800 nm. Theoretical calculations showed the presence of mixed charge‐transfer transitions and localized transitions on the azahelicene units, which led to a broad light‐absorbing property covering the near IR region. Additionally, we conducted measurements of circular dichroism and circularly polarized luminescence for the obtained products. The g‐values were reduced by oligomerization, indicating that the lowest energy transitions were allowed in nature. [ABSTRACT FROM AUTHOR]

Tetra‐cyano substituted naphthalene diimides (TCNDIs) with calculated LUMO of −5.2 eV, form one of the strongest electron‐acceptors known to date. However, the synthesis and isolation of this class of molecules remain challenging due to its reactivity emanating from its ultra‐electron‐deficiency. Herein we have established an improved synthetic methodology of TCNDIs with cost‐effective reagents and circumventing metallic catalysts. The synthesis is amenable to TCNDIs with the shortest axial alkyl groups, i. e. methyl group and also longer alkyl chains. We also gained insight on how axial alkyl chain lengths influence electron‐deficiency, Meisenheimer complex formation, reactivity, and charge‐transfer of TCNDIs from computation, spectroscopy, and electrochemical studies. The TCNDIs with Me/Et axial groups were found to be more susceptible to moist solvents vis‐à‐vis the TCNDIs with longer alkyl groups. The single crystal structures of the TCNDIs show infinitely π‐stacked structure, and a new C=O ⋅ ⋅ ⋅ C≡N or C≡N ⋅ ⋅ ⋅ π motif is discerned. Finally, toluene‐mediated charge‐transfer properties of TCNDIs in the single crystals as well as in solution have been examined. [ABSTRACT FROM AUTHOR]

Here, the mechanism of charge‐disproportionation (CD) in BaBiO3 (BBO) using density functional theory under different crystal symmetries and by employing strain as an external perturbation is investigated. The competition between Bi 6sp–O 2p (s‐p) and O 2p–O 2p (p‐p) or Bi 6p–O 2p charge fluctuations decides the electronic ground state, CD, and bond‐disproportionation (BD) in BBO. An extended Hubbard Hamiltonian involving onsite (U) and long‐range (V) coulomb repulsion is also employed to ascertain the microscopic conditions for forming the lone pair on the bismuth site. A strong tensile strain increases p‐p fluctuation and drives the system into a strong negative‐CT character, while a strong compressive strain favors s‐p fluctuation leading to the enhanced positive‐CT character. This indicates that the change transfer energy of the bulk BBO can be tuned with external strain. [ABSTRACT FROM AUTHOR]

Here, the mechanism of charge‐disproportionation (CD) in BaBiO3 (BBO) using density functional theory under different crystal symmetries and by employing strain as an external perturbation is investigated. The competition between Bi 6sp–O 2p (s‐p) and O 2p–O 2p (p‐p) or Bi 6p–O 2p charge fluctuations decides the electronic ground state, CD, and bond‐disproportionation (BD) in BBO. An extended Hubbard Hamiltonian involving onsite (U) and long‐range (V) coulomb repulsion is also employed to ascertain the microscopic conditions for forming the lone pair on the bismuth site. A strong tensile strain increases p‐p fluctuation and drives the system into a strong negative‐CT character, while a strong compressive strain favors s‐p fluctuation leading to the enhanced positive‐CT character. This indicates that the change transfer energy of the bulk BBO can be tuned with external strain. [ABSTRACT FROM AUTHOR]

Charge transfer (CT) crystals exhibit unique electronic and magnetic properties with interesting applications. We present a rational and easy guide which allows to foresee the effective charge transfer co‐crystal production and that is based on the comparison of the frontier molecular orbital (MO) energies of a donor and acceptor couple. For the sake of comparison, theoretical calculations have been carried out by using the cheap and fast PM6 semiempirical Hamiltonian and pure HF/cc‐pVTZ level of the theory. The results are then compared with experimental results obtained both by chemical (bromine and iodine were used as the acceptor) and electrochemical doping (exploiting an original experimental set‐up by this laboratory: the electrochemical transistor). Infra‐red vibrational experimental results and theoretically calculated spectra are compared to assess both the effective donor‐acceptor (D/A) charge‐transfer and transport mechanism (giant IRAV polaron signature). XPS spectra have been collected (carbon (1 s) and iodine (3d5/2)) signals, yielding further evidence of the effective formation of the CT anthracene:iodine complex. [ABSTRACT FROM AUTHOR]

The charge‐transfer (CT) interactions between organic compounds are reflected in the (opto)electronic properties. Determining and visualizing crystal structures of CT complexes are essential for the design of functional materials with desirable properties. Complexes of pyranine (PYR), methyl viologen (MV), and their derivatives are the most studied water‐based CT complexes. Nevertheless, very few crystal structures of CT complexes have been reported so far. In this study, the structures of two PYRs‐MVs CT crystals and a map of the noncovalent interactions using 3D electron diffraction (3DED) are reported. Physical properties, e.g., band structure, conductivity, and electronic spectra of the CT complexes and their crystals are investigated and compared with a range of methods, including solid and liquid state spectroscopies and highly accurate quantum chemical calculations based on density functional theory (DFT). The combination of 3DED, spectroscopy, and DFT calculation can provide important insight into the structure‐property relationship of crystalline CT materials, especially for submicrometer‐sized crystals. [ABSTRACT FROM AUTHOR]

Ag3BiI6 (ABI) is one of the most widely explored lead‐free perovskite‐inspired materials for eco‐friendly solar cell applications. However, despite the intense research efforts, the photovoltaic performance of ABI‐based devices remains very modest, primarily due to poor film morphology and ineffective charge extraction. This work aims at investigating the potential benefits of a thermally evaporated cesium iodide (CsI) interlayer on the performance of ABI‐based solar cells. Upon the addition of CsI atop the ABI layer in the device stack, the solar cells deliver a power conversion efficiency (PCE) of 2.27%. This is the highest efficiency reported for ABI solar cells employing a similar device architecture. It is found that the enhancement in PCE is largely due to improvement in the ABI|hole transport layer interface upon the introduction of CsI interlayer. The improvement is largely ascribed to enhanced surface coverage upon introduction of CsI interlayer, as evidenced by our comprehensive microscopy studies. Furthermore, impedance spectroscopy analysis is employed to provide further insights into the changes in charge transfer dynamics interlayer that dictate the enhancement of fill factor and short‐circuit current density in the devices. The findings indicate that the addition of CsI promotes charge transfer and minimizes recombination losses.

Photophysical modulation of triarylboranes (TABs) through Lewis acid‐base interactions is a fundamental approach for sensing anions. Yet, design principles for anion‐responsive TABs displaying significant red‐shift in absorption and photoluminescence (PL) have remained elusive. Herein, a new strategy for modulating the photophysical properties of TABs in a red‐shift mode has been presented, by using a nitrogen‐bridged triarylborane (1,4‐phenazaborine: PAzB) with a contradictory dual role as a Lewis acid and an electron donor. Following the strategy, PAzB derivatives connected with an electron‐deficient azaaromatic have been developed, and these compounds display a distinct red‐shift in their absorption and PL in response to an anion. Spectroscopic analyses and quantum chemical calculations have revealed the formation of a tetracoordinate borate upon the addition of fluoride, narrowing the HOMO–LUMO gap and enhancing the charge‐transfer character in the excited state. This approach has also been demonstrated in modulating the photophysical properties of solid‐state films. [ABSTRACT FROM AUTHOR]

A dication of [5]cycloparaphenylene ([5]CPP2+) was selectively encapsulated by neutral [10]CPP to form the shortest double-layer carbon nanotube, [10]CPP⊃[5]CPP2+. While the same host–guest complex consisted of neutral CPPs, [10]CPP⊃[5]CPP, was already reported, the cationic complex showed an about 20 times higher association constant in (CDCl2)2 at 25 °C (103 mol L−1). Electrochemical and photophysical analyses and theoretical calculations suggested the partial electron transfer from [10]CPP to [5]CPP2+ in the complex, and this charge-transfer (CT) interaction is most likely the origin of the higher association constant of the dicationic complex than the neutral one.

NiFeLDH (Layered double hydroxide) semiconductors are promising for harnessing light energy. The development of transition metal-based photocatalysts consisting of rhodium building blocks is not only beneficial for the separation and transfer of photo-generated carriers in photocatalytic reactions but also an effective means of widening the optical window of light absorption. In this report, a facile hydrothermal approach is employed in modulating NiFeLDH nanosheets arrays with optimal molar ratio of Rhodium (Rh) in LDH to engineer a robust hierarchical NiFeLDH-Rh photocatalytic system towords efficient hydrogen evolution reaction (HER) under visible light. In a systematic investigation, the NiFeLDH is grown on nickel foam and controlled doping of Rhodium led to fine-tuning of their electronic structure and efficient visible light-driven proton reduction system due to its multiple accessible active sites boosting the photocatalytic performance. Furthermore, the 2D hierarchical nanosheet arrays can speed up electron diffusion and assure fast electron/mass transfer while maintaining high photocatalytic stability. The NiFeLDH-Rh composite demonstrated an enhanced hydrogen generation rate of 2.09 mmolg−1h−1 (AQY = 6.1%). The photocurrent density and transient photocurrent curve show rapid charge transfer as well as the unique electron transfer paths through the contact surface, resulting in efficient charge separation. Moreover DFT and photoelectrochemical studies reveal higher HER activity due to the augmented electric field between Rh and NiFeLDH complex. This research offers a novel strategy and new insights into the investigation of highly active photocatalysts for overall water splitting. [Display omitted] • Facile synthesis of rhodium-doped nickel iron double hydroxide 2D nanosheets. • Rh doped NiFeLDH ultrathin sheets significantly tune the band gap to boost HER. • Mechanistic investigation unveiled efficient photoexcited charge carriers. • Catalyst showed H 2 evolution rate of 2.09 mmolg−1h−1 and AQY = 6.1%. • Theoretical and experimental studies supports superior photocatalytic performance. [ABSTRACT FROM AUTHOR]

Currently, developing highly active and low-cost electrocatalytic materials for oxygen evolution reaction (OER) is an enormously grand challenge. Herein, we developed a novel and highly active Mn doped Co 2 Fe layer double hydroxide (LDH) electrocatalyst for OER. We discovered that these electrocatalytic materials can be directly grown on carbon papers to construct high-specific-surface-area electrode, which shows the lowest overpotential of 266 mV at 10 mA cm−2. Furthermore, after introducing Mn element, DFT + U calculation found that the ∗OOH of Fe-site on Co 2 Fe 0.67 Mn 0.33 LDH could draw more electrons than Co 2 Fe LDH due to the electronegativity differences between Fe-site on Co 2 Fe 0.67 Mn 0.33 LDH and Fe-site on Co 2 Fe LDH, which is reason that the energy level of Fe 3d (e g) was obviously downshifted by d-d repulsion of Mn 3d and Fe 3d in the neighboring sites of Co 2 Fe 0.67 Mn 0.33 LDH after doped Mn element, which leads to reduce charge-transfer energy from O 2p to Fe 3d (e g) to promote oxygen evolution processes for OER. Meanwhile, the band gap is also decreased after doped Mn element in Co 2 Fe LDH due to the downshifted e g orbital energy of Fe 3d. This study gives a general avenue to design and developing efficiently active LDH electrocatalysts for OER in the future. • Both bimetallic CoFe LDH and Mn doped CoFe LDHs directly grown on carbon paper are successfully synthesized. • The Co 2 Fe 0.67 Mn 0.33 LDH@NFs exhibits a small overpotential of 236 mV at 10 mA cm−1 for OER. • DFT + U studies reveal that the observed superb OER activity could be attributed to d-d repulsion of Mn 3d and Fe 3d. [ABSTRACT FROM AUTHOR]

We have investigated the potential energy curves (PECs) of the LiN heteronuclear diatomic molecule, including its ionic species LiN+ and LiN−, using explicitly correlated multi‐reference configuration interaction (MRCI‐F12) calculations in conjunction with the correlation consistent quintuple‐휁 basis set. The effect of core–valence correlation, scalar relativistic effects, and the size of the basis sets has been investigated. A comprehensive set of spectroscopic constants determined based on the above‐mentioned calculations are also reported for the lowest electronic states and all systems, including dissociation energies, harmonic and anharmonic vibrational frequencies, and rotational constants. Additional parameters, such as the dipole moments, equilibrium spin‐orbit constants, excitation energies, and rovibrational energy levels, are also documented. We found that the three triplet states of LiN, namely, X 3∑−, A 3Π, and 2 3∑−, exhibit substantial potential wells in the PEC diagrams, while the quintet states are repulsive in nature. The ground state of the anion also shows a deep potential well in the vicinity of its equilibrium geometry. In contrast, the ground and excited states of the cation are very loosely bound. Charge transfer properties of each of these states are also analyzed to obtain an in‐depth understanding of the interatomic interactions. We found that the core–valence correlation has a substantial effect on the calculated spectroscopic constants. [ABSTRACT FROM AUTHOR]

A series of 1,8-naphthalimide (NI)-phenothiazine (PTZ) electron donor–acceptor dyads were prepared to study the thermally activated delayed fluorescence (TADF) properties of the dyads, from a point of view of detection of the various transient species. The photophysical properties of the dyads were tuned by changing the electron-donating and the electron-withdrawing capability of the PTZ and NI moieties, respectively, by oxidation of the PTZ unit, or by using different aryl substituents attached to the NI unit. This tuning effect was manifested in the UV–vis absorption and fluorescence emission spectra, e.g., in the change of the charge transfer absorption bands. TADF was observed for the dyads containing the native PTZ unit, and the prompt and delayed fluorescence lifetimes changed with different aryl substituents on the imide part. In polar solvents, no TADF was observed. For the dyads with the PTZ unit oxidized, no TADF was observed as well. Femtosecond transient absorption spectra showed that the charge separation takes ca. 0.6 ps, and admixtures of locally excited (3LE) state and charge separated (1CS/3CS) states formed (in n-hexane). The subsequent charge recombination from the 1CS state takes ca. 7.92 ns. Upon oxidation of the PTZ unit, the beginning of charge separation is at 178 fs and formation of 3LE state takes 4.53 ns. Nanosecond transient absorption (ns-TA) spectra showed that both 3CS and 3LE states were observed for the dyads showing TADF, whereas only 3LE or 3CS states were observed for the systems lacking TADF. This is a rare but unambiguous experimental evidence that the spin–vibronic coupling of 3CS/3LE states is crucial for TADF. Without the mediating effect of the 3LE state, no TADF is resulted, even if the long-lived 3CS state is populated (lifetime τCS ≈ 140 ns). This experimental result confirms the 3CS → 1CS reverse intersystem crossing (rISC) is slow, without coupling with an approximate 3LE state. These studies are useful for an in-depth understanding of the photophysical mechanisms of the TADF emitters, as well as for molecular structure design of new electron donor–acceptor TADF emitters.

Theoretical study of the photophysical/photochemical properties of 1H‐benzimidazole and its derivatives was carried out using APFD, B3LYP, CAM‐B3LYP and PBE0 density functionals with 6‐311+G(2d,p) basis set. The effects of ethanol, 1,4‐dioxane, acetonitrile and water was investigated by means of Integral Equation Formalism of the Polarizable Continuum Model (IEPCM) in the framework of Self‐Consistent Reaction Field (SCRF). The results obtained show that S2 state of the 1H‐benzimidazole molecule is more acidic than the S0 state as the N5−H11 bond length increased to ~ 1.01 Å. At B3LYP/6‐311+G(2d,p) level of theory, the excitation energy of 1H‐bensimidazole molecule in ethanol from S0 to the S2 state was calculated to be 273 nm (4.54 eV). The electronic energy for this transition was calculated to be 0.131 a.u. and observed to occur between π→π* orbitals. Calculations with the PBE0, APFD and B3LYP functionals reproduced the experimental dipole moment in 1,4‐dioxane, with values of 4.09, 4.09 and 4.07 Debye respectively. However, the dipole moments of the 2‐ethyl‐7‐nitro‐5‐substituted‐1H‐benzimidazoles were calculated to be higher for electron donating groups (EDGs) than those bearing electron withdrawing groups (EWGs). In addition, the molecular polarizability was observed to increase with decreasing energy gap. Local excitation (LE) and charge‐transfer (CT) were observed to mediate the mechanisms of electronic excitation in 2‐ethyl‐7‐nitro‐5‐substituted‐1H‐benzimidazoles. [ABSTRACT FROM AUTHOR]

In the current research study, the adsorbent efficacy of an aluminum carbide (AlC3) nanosheet for edifenphos fungicide is assessed for the first time. To explore the efficacy of AlC3 as an adsorbent system, several essential properties of edifenphos, AlC3, and the complex of edifenphos-AlC3 are investigated. Edifenphos has an interaction through its -P = O group with the Al atoms of AlC3 with adsorption energy (Eads) of approximately −34.46 kcal/mol. The charge-transfer process is investigated by carrying out the LUMO-HOMO analysis, which is further supported by the NBO analysis. The net value of charge transfer from the edifenphos to AlC3 in the most stable complex is about 0.526 e. In addition, during edifenphos adsorption on the AlC3 surface the energy gap (Eg) of AlC3 was reduced from 2.25 to 1.17 eV. Also, the solvation energy (Esol) values of edifenphos@AlC3 are calculated to be −40.29 kcal/mol, which indicates that edifenphos@AlC3 is stabilized by water via spontaneous solvation. Overall, the results demonstrate that AlC3 can be employed as an effective adsorbent system for edifenphos to treat different forms of wastewater. [ABSTRACT FROM AUTHOR]

The ability to tailor oxide heterointerfaces has led to novel properties in low-dimensional oxide systems. A fundamental understanding of these properties is based on the concept of electronic charge transfer. However, the electronic properties of oxide heterointerfaces crucially depend on their ionic constitution and defect structure: ionic charges contribute to charge transfer and screening at oxide interfaces, triggering a thermodynamic balance of ionic and electronic structures. Quantitative understanding of the electronic and ionic roles regarding charge-transfer phenomena poses a central challenge. Here, the electronic and ionic structure is simultaneously investigated at the prototypical charge-transfer heterointerface, LaAlO3 /SrTiO3 . Applying in situ photoemission spectroscopy under oxygen ambient, ionic and electronic charge transfer is deconvoluted in response to the oxygen atmosphere at elevated temperatures. In this way, both the rich and variable chemistry of complex oxides and the associated electronic properties are equally embraced. The interfacial electron gas is depleted through an ionic rearrangement in the strontium cation sublattice when oxygen is applied, resulting in an inverse and reversible balance between cation vacancies and electrons, while the mobility of ionic species is found to be considerably enhanced as compared to the bulk. Triggered by these ionic phenomena, the electronic transport and magnetic signature of the heterointerface are significantly altered.

A number of electron-rich heterocycles are studied as potential reagents for visual colorimetric detection of FOX-7 due to colored charge-transfer complexes formation. The obtained results suggest that pyrrole and pyrimidine derivatives can form such complexes playing the role of electron donors despite a low electrophilicity of FOX-7. Density functional theory calculations, as well as quantum theory of atoms in molecules analysis, suggest stacking binding mode as the most preferable one with the binding energy of about 21-36kJ/mol. All the complexes demonstrate a clear single charge-transfer absorption band in the visible region and the expected colors of the complexes are varying from violet and blue to red and orange. The calculations of the crystalline state of the studied complexes indicate high lattice energies, which are higher than that of pure FOX-7 and are close to the recently reported hydrogen-bonded complex of FOX-7 with 1,10-phenanthroline. Additional analysis of the studied charge-transfer complexes using properties based on density difference grids clearly suggests the acceptor role of FOX-7 in the complexes. This analysis can be effectively applied to identify the nature of other possible complexes of FOX-7, in which its role is unclear because of the specific reactivity, namely, both weak electrophilic and nucleophilic properties at the same time. [ABSTRACT FROM AUTHOR]

The paper reports on the synthesis and fluorescence characteristics of novel 1,8-naphthalimide fluorophore. It was configured as a “fluorophore-spacerreceptor” system able to act as a pH-probe via PET (photoinduced electron transfer) fluorescence sensing mechanism. Due to the tertiary amine receptor the novel probe showed “off-on” switching properties under the transition from alkaline to acid media. Also, the ability of the probe to detect metal ions in water/ dimethylformamide (1:1, v/v) has been evaluated by monitoring the changes of its fluorescence intensity. Among the tested metal ions (Cu2+, Pb2+, Zn2+, Ni2+, Hg2+,Fe3+) only the presence of Fe3+ was efficiently detected by fluorescence quenching mechanism.

In order to investigate the joint influence of the conformation flexibility and the matching of the energies of the charge-transfer (CT) and the localized triplet excited (3LE) states on the thermally activated delayed fluorescence (TADF) in electron donor–acceptor molecules, a series of compact electron donor–acceptor dyads and a triad were prepared, with naphthalimide (NI) as electron acceptor and phenothiazine (PTZ) as electron donor. The NI and PTZ moieties are either directly connected at the 3-position of NI and the N-position of the PTZ moiety via a C–N single bond, or they are linked through a phenyl group. The tuning of the energy order of the CT and LE states is achieved by oxidation of the PTZ unit into the corresponding sulfoxide, whereas conformation restriction is imposed by introducing ortho-methyl substituents on the phenyl linker, so that the coupling magnitude between the CT and the 3LE states can be controlled. The singlet oxygen quantum yield (ΦΔ) of NI-PTZ is moderate in n-hexane (HEX, ΦΔ = 19%). TADF was observed for the dyads, the biexponential luminescence lifetime are 16.0 ns (99.9%)/14.4 μs (0.1%) for the dyad and 7.2 ns (99.6%)/2.0 μs (0.4%) for the triad. Triplet state was observed in the nanosecond transient absorption spectra with lifetimes in the 4–48 μs range. Computational investigations show that the orthogonal electron donor–acceptor molecular structure is beneficial for TADF. These calculations indicate small energetic difference between the 3LE and 3CT states, which are helpful for interpreting the ns-TA spectra and the origins of TADF in NI-PTZ, which is ultimately due to the small energetic difference between the 3LE and 3CT states. Conversely, NI-PTZ-O, which has a higher CT state and bears a much more stabilized 3LE state, does not show TADF.

Strongly correlated electronic molecules open the way for strong coupling between charge, spin, and lattice degrees of freedom to enable interdisciplinary fields, such as molecular electronic switches and plasmonics, spintronics, information storage, and superconducting circuits. However, despite exciting computational predictions and promising advantages to prepare flexible geometries, the electron correlation effect in molecules has been elusive. Here, the electron correlation effects of molecular plasmonic films are reported to uncover their coupling of charge, spin, lattice, and orbital for the switchable metal-to-insulator transition under external stimuli, at which the simultaneous transition occurs from the paramagnetic, electrical, and thermal conducting state to the diamagnetic, electrical, and thermal insulating state. In addition, density functional theory calculation and spectroscopic studies are combined to provide the mechanistic understanding of electronic transitions and molecular plasmon resonance observed in molecular conducting films. The self-assembled molecular correlated conductor paves the way for the next generation integrated micro/nanosystems.

A new class of diamino‐substituted π‐extended phenazine compound was synthesized, and its photophysical properties were investigated. The U‐shaped diaminophenazine displayed photoluminescence in solution with moderate quantum yield. The diamino aromatic compound was found applicable to the poly‐condensation with formaldehyde to form Tröger's base ladder polymer. The obtained microporous ladder polymer features high CO2 adsorption selectivity against N2, most likely due to the presence of basic nitrogen atoms in the phenazine rings. [ABSTRACT FROM AUTHOR]

Hydrogels behave as potential candidates to investigate circularly polarized light (CP)‐matter interaction, which however suffer from small sensitivity towards circular polarization. Here we report a general protocol to build hydrogels from π‐conjugated amino acids with coassembled charge‐transfer (CT) complexes, covering a wide scope of donors and acceptors, which were incorporated into stable hydrogel matrices. CT complexes formed block coassemblies with gelators, induced the emergence of macroscopic chiral helices, where efficient chirality transfer occurs to realize tunable Cotton effects from visible light to NIR‐I region depending on the structures of CT pairs. The hybrid hydrogels showed tunable photothermal performances with excellent heating‐cooling cycling durability. Circularly polarized NIR light selectively triggered gel‐solution phase transition at different timescales. Left‐ and right‐CP illumination generates up to 2.5 folds difference in gel collapse time that allows for direct discrimination by naked eyes. [ABSTRACT FROM AUTHOR]

Flexible tribovoltaic direct‐current (DC) generators are urgently expected by wearable applications. Traditional rigid contact‐separation type tribovoltaic DC generators normally have non‐ignorable friction loss and cannot sustain outstanding outputs. This hinders their serviceability in continuous motion scenarios. Here, flexible liquid‐based DC generators (FLGs) with metal‐liquid‐semiconductor indium gallium zinc oxide (IGZO) stack structures are reported. The FLG with Pt/H2O/IGZO structure delivers a peak short‐circuit current density up to 2.3 µA cm−2, a peak open‐circuit voltage up to 620 mV, and a power density up to 0.1 µW cm−2. The differences in the properties of different liquid–solid interfaces are studied by density functional theory, showing that the bond formation, charge‐transfer‐induced dipole electric field at the solid‐liquid interface, and the built‐in electric field are responsible for the generation and separation of electron‐hole pairs to form continuous DC. The proposed FLG can keep excellent performance even after >5 × 104 shaking cycles or exposing to ambient conditions for 30 days, showing extraordinary stability. Besides charging capacitors or driving LEDs, the FLG is further demonstrated to work for self‐powered multifunctional sensing, enabling pressure, position‐posture, or temperature detections. This design offers potential solutions and novel possibilities for next‐generation self‐powered wearable electronics. [ABSTRACT FROM AUTHOR]

A new thermally activated delayed fluorescence (TADF) compound based on a donor–acceptor (D–A) architecture (D = phenoxazine; A = dibenzo[a,j]phenazine) has been developed, and its photophysical properties were characterized. The D–A compound is applicable as an emitting material for efficient organic light-emitting diodes (OLEDs), and its external quantum efficiency (EQE) exceeds the theoretical maximum of those with prompt fluorescent emitters. Most importantly, comparative study of the D–A molecule and its D–A–D counterpart from the viewpoints of the experiments and theoretical calculations revealed the effect of the number of the electron donor on the thermally activated delayed fluorescent behavior.

Ample visible-light response and efficient charge transfers in semiconductor heterojunction are still enslaved to the limited photocatalytic water splitting. In most cases, the rational design of hybrid composites tune in atomic level interaction led to remarkable stability and superior activity. Here, this work is a systematic investigation of metal ion substitution in the LDH and LDH/g-C 3 N 4 hybrid composites for hydrogen evolution reaction (HER) under visible light. The construction of heterostructure not only facilitates the charge separation and transfer owing to the formed heterojunction through band gap engineering and tunable optical properties which are inherited from morphology of as grown CuCdCe-LDH over the exfoliated g-C 3 N 4 but also provides plenty of surface active sites due the increased surface area photostability. The CuCdCe-LDH/g-C 3 N 4 exhibits superior HER rate of 3.5 mmolg−1h−1 with AQY of 5.78% over their binary counterparts. The density functional theory calculations also suggest that the HER activity of CuCdCe-LDH is substantially enhanced by coupling with g-C 3 N 4 the electrochemical results leading to high photocurrent response. The high photocatalytic activity of the composite was due to efficient photoexcited charge transfer process and the synergistic effect between CuCdCe-LDH and g-C 3 N 4. These finding will open scopes for designing inexpensive high performance materials for broad applications of photocatalytic energy conversion. [Display omitted] • The composite hybrid structure CuCdCe-LDH/g-C 3 N 4 was prepared through facile synthesis route. • Compositional modulation (Cu, Cd and Ce in LDH) improves the visible light (> 400 nm) absorption. • The heterojunction interface between CuCdCe-LDH and g-C 3 N 4 promotes efficient charge carriers. • The photocatalyst exhibited impressive HER of 3.5 mmolg−1h−1 under photo-irradiation. • A combinatorial approach of theoretical and experimental studies supports superior performance of HER. [ABSTRACT FROM AUTHOR]

[Display omitted] Charge-transfer assemblies (CTAs) represent a new class of functional material due to their excellent optical properties, and show great promise in the biomedical field. Porphyrins are widely used photosensitizers, but the short absorption wavelengths may restrict their practical applications. To obtain porphyrin phototherapeutic agents with red-shifted absorption, charge-transfer nanoscale assemblies (TAPP-TCNQ NPs) of 5,10,15,20-tetrakis(4-aminophenyl) porphyrin (TAPP) and 7,7,8,8‑tetracyanoquinodimethane (TCNQ) were prepared via optimizing the stoichiometric ratios of donor–acceptor. The as-prepared TAPP-TCNQ NPs exhibit red-shifted absorption to the near-infrared (NIR) region and enhanced absorbance because of the charge-transfer interactions. In especial, TAPP-TCNQ NPs possess the capacity of both photodynamic and photothermal therapy, thus effectively killing the bacteria upon 808 nm laser irradiation. This modular assembly method provides an alternative strategy to enhance the application of the phototherapeutic agents. [ABSTRACT FROM AUTHOR]

Catechol adsorbed on TiO2 is one of the simplest models to explore the relevant properties of dye-sensitized solar cells. However, the effects of water and defects on the electronic levels and the excitonic properties of the catechol/TiO2 interface have been rarely explored. Here, we investigate four catechol/TiO2 interfaces aiming to study the influence of coverage, water, and defects on the electronic levels and the excitonic properties of the catechol/TiO2 interface through the first-principles many-body Green's function theory. We find that the adsorption of catechol on the rutile (110) surface increases the energies of both the TiO2 valence band maximum and conduction band minimum by approximately 0.7 eV. The increasing coverage and the presence of water can reduce the optical absorption of charge-transfer excitons with maximum oscillator strength. Regarding the reduced hydroxylated TiO2 substrate, the conduction band minimum decreases greatly, resulting in a sub-bandgap of 2.51 eV. The exciton distributions in the four investigated interfaces can spread across several unit cells, especially for the hydroxylated TiO2 substrate. Although the hydroxylated TiO2 substrate leads to a lower open-circuit voltage, it may increase the separation between photogenerated electrons and holes and may therefore be beneficial for improving the photovoltaic efficiency by controlling its concentration. Our results may provide guidance for the design of highly efficient solar cells in future. [ABSTRACT FROM AUTHOR]

Polar crystals have attracted interest for the applications to polar materials with piezo‐ and pyroelectricity, and second harmonic generation. Despite their potential utility for flexible polar materials, a strategy for ordering polar helicenes has remained elusive. Here, we demonstrate the creation of polar crystals with unsymmetrically substituted aza[5]helicenes tuned by substituents. The unsymmetric aza[5]helicenes have been prepared through regioselective mono‐protiodesilylations. We disclose that triisopropylsilyl‐substituted derivatives show 1D chain columnar packings. In particular, enantiopure crystals showed spontaneous polarization. Optical and single‐crystal X‐ray diffraction experiments with other derivatives, as well as theoretical calculations, revealed that the presence of triisopropylsilyl or electron‐withdrawing aryl substituents is essential for forming the 1D chain columnar structure. Hirshfeld surface analyses further showed that CH‐π interactions between 1D chain columns regulate the polar assembly. Finally, we determined the polarizability of the nitro derivative by ab initio calculation to be 4.53 μC/cm2. This value corroborates the first example of a spontaneously polar crystal of helicenes. We believe that this study will contribute to the development of polar materials from organic molecules. [ABSTRACT FROM AUTHOR]

This paper describes the influence of the transannular π–π interaction in controlling the carrier transport in molecular wires by employing the STM break junction technique. Five pentaphenylene-based molecular wires that contained [2.2]paracyclophane-1,9-dienes (PCD) as the building block were prepared as model compounds. Functional substituents with different electronic properties, ranging from strong acceptors to strong donors, were attached to the top parallel aromatic ring and used as a gate. It was found that the carrier transport features of these molecular wires, such as single-molecule conductance and a charge-tunneling barrier, can be systematically controlled through the transannular π–π interaction. [ABSTRACT FROM AUTHOR]

In the present work, nanocrystalline samples of compositionsNixFe1-xCo2O4(x= 0.0, 0.25, 0.50, and 0.75) have been synthesized via co-precipitation method by annealing at 900 °C. The nanocrystalline samples of compositions Ni 0.25 Fe 0.75 Co 2 O 4 (D 0.25 ) and Ni 0.5 Fe 0.5 Co 2 O 4 (D 0.5 ) crystallizes in a pure spinel phase, whereas Ni 0.75 Fe 0.25 Co 2 O 4 (D 0.75 ) show the existence of secondary phase of NiO, as confirmed by the x-ray diffraction analysis. The particle size and lattice strain in the samples both decrease as Ni substitution has increased. The field-dependent dc magnetization M ( H ) virgin curve measured at 5 K for sample D 0.75 shows the existence of field-induced metamagnetic transition, while this behavior is absent in samples D 0.5 and D 0.25 . Dynamic magnetic properties have been investigated by ac susceptibility measurement, which shows a strong frequency dependence behavior resulting from the blocking/spin-glass freezing states depending upon the amount of Ni substitution and the range of measurement temperature. High-resolution x-ray photoelectron spectroscopy analysis reveals the presence of mixed valence states of Fe 2+ /Fe 3+ , Co 2+ /Co +3 , and Ni 2+ /Ni +3 in all samples. Using first principles-based density functional theory calculations with HSE06 exchange-correlation functional predicts the correct description of the ground state, which is ferrimagnetic and insulating in their inverse spinel case for D 0.25 , D 0.5 , and D 0.75 samples that agreed well with our experimental observations. A closer look at the electronic structure near the Fermi level ( E ) of Ni-doped samples suggests a typical Mott-Hubbard insulating state while it is found to be a mixture of charge-transfer and Mott-Hubbard insulating state for parent compound FeCo F ) of Ni-doped samples suggests a typical Mott-Hubbard insulating state while it is found to be a mixture of charge-transfer and Mott-Hubbard insulating state for parent compound FeCo 2 O 4 . The obtained spin-dependent gap hierarchy can have possible applications in spintronics. We have studied a detailed correlation between experiment and theory., (© 2024 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.)

1,4-Dialkylamino -5,8-dihydroxy anthraquinones are investigated using density functional theory (DFT) and time-dependent DFT (TD-DFT) for their growth inhibitory potential. The frontier molecular orbital shows that the electron density is located at the anthraquinone core and at the substituents NH and OH in both HOMO as well as in LUMO. The chemical potential and electrophilicity index showed a direct relation, while hardness and hyperhardness had an inverse association with an energy gap. The results of the molecular docking analysis revealed that the anthraquinone molecules have a high affinity for the primary targets of the DNA topoisomerase IIα enzyme. The docking results showed good binding ability with extremely energetically stable scores ranging from -8.9 to -7.6 kcal/mol. Electron correlation descriptors showed a direct link with NLO properties and toxicity.

The design of heterojunctions offers a crucial solution for energy conversion and storage challenges, but current research predominantly focuses on charge transfer benefits, often neglecting spin attribute regulation despite the increasing recognition of spin-sensitivity in many chemical reactions. In this study, a novel magnetic heterostructure, CoFe 2 O 4 @CoFeMo 3 O 8 , is designed to simultaneously modulate charge and spin characteristics, and systematically elucidated their synergistic impact on the oxygen evolution reaction (OER). Experimental results and density functional theory calculations confirmed that the magnetic heterostructure exhibits both charge transfer and spin polarization. It is found that the charge-transfer behavior enhances conductivity and adsorption ability through band structure regulation. Meanwhile, magnetically polarized electrons promote triplet O 2 generation and accelerate electron transport via spin-selective pathways. Moreover, the heterostructure's effective response to external alternating magnetic fields further amplifies the spin-dependent effect and introduces a magnetothermal effect, locally heating the active sites through spin flip, thereby boosting catalytic activity. Consequently, the OER activity of the magnetic heterostructure is improved by 83.8 times at 1.5 V compared to its individual components. This magnetic heterojunction strategy presents a promising avenue for advanced catalysis through synergistic regulating of charge-transfer and spin-ordering., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Twisted transition metal dichalcogenide (TMD) bilayers exhibit periodic moiré potentials, which can trap excitons at certain high-symmetry sites. At small twist angles, TMD lattices undergo an atomic reconstruction, altering the moiré potential landscape via the formation of large domains, potentially separating the charges in-plane and leading to the formation of intralayer charge-transfer (CT) excitons. Here, we employ a microscopic, material-specific theory to investigate the intralayer charge-separation in atomically reconstructed MoSe 2 -WSe 2 heterostructures. We identify three distinct and twist-angle-dependent exciton regimes including localized Wannier-like excitons, polarized excitons, and intralayer CT excitons. We calculate the moiré site hopping for these excitons and predict a fundamentally different twist-angle-dependence compared to regular Wannier excitons - presenting an experimentally accessible key signature for the emergence of intralayer CT excitons. Furthermore, we show that the charge separation and its impact on the hopping can be efficiently tuned via dielectric engineering.

Manipulating the properties of 2D materials through meticulously engineered artificial heterojunctions holds great promise for novel device applications. However, existing research on the crucial charge-transfer interactions and energy profile regulation is predominantly focused on 2D van der Waals structures formed via weak van der Waals forces, limiting regulatory efficiency at high costs. Herein, a refined atomic-molecular heterojunction strategy featuring strong covalent bonds between organic molecule and 2D violet phosphorus (VP) atomic crystal is developed, which enables enhanced charge-transfer dynamics and customizable band structure regulation at the molecular level. Both experimentally and theoretically, it is demonstrated that grafting efficiency, charge redistribution, and energy gap regulation critically depend on organic electronegativity, providing a low-cost yet high-efficiency regulatory effect on a large scale. As a proof of concept, the novel VP-molecular heterojunctions exhibit optimized performance in diverse application domains, presenting a general platform for future high-performance device applications., (© 2024 Wiley‐VCH GmbH.)

The effect of interfacial layer (SnOx) on the performance of the complementary electrochromic devices (ECDs) was examined, revealing that the SnOx/WO3 bilayer cathodes could enhance the electrochromic performance, such as a superior long-term cycling stability over 10,000 cycles, a high coloration efficiency of 101.61 cm2 C−1 and a maximum transmittance modulation of 49.27%@633 nm. Moreover, compared with the single layer WO3, the SnOx/WO3 bilayer exhibited improved electrochemical activities and reaction kinetics. The probable explanation is that the introduced interfacial layer can boost the double injection of ions and electrons, balance the transport of ions and electrons, and protect the electrode from degradation by serving as a buffer layer during coloration/bleaching cycles. These results further provide a valuable insight for improving the electrochromic properties of the films instead of relying on conventional methods such as nanostructural or compositional control.

• Six new charge transfer complexes have been synthesized. • The complex structures exhibited a variety of morphologies. • The optimal stoichiometric ratio of donor to acceptor was confirmed to be 1:1. • C N and N H in the donor and COOH in the acceptor played a key role. Six new charge-transfer complexes using ofloxacin (OFL) and sulfamethazine (SMR) as electron donors and coumaric acid (COA), cinnamic acid (CNA), and salicylic acid (SAA) as acceptors via equimolar mixture have been synthesized. The experiment used UV–vis spectroscopy to determine the formation of the complex in methanol through the presence of a new broad absorption band with a maximum wavelength in the 200–400 nm range. The molecular composition of the charge-transfer complexes was determined by the spectrophotometric titration method and found to be 1:1 (donor: acceptor). These complexes have been characterized by infrared (FTIR) and scanning electron microscopy (SEM). In the FTIR spectra, the CT complexes showed a wavelength shift compared to the reactants. The complexes exhibited various morphologies by SEM, including spherical particles, short rods, and flattened shapes. Additionally, quantum chemical calculations at the DFT/B3LYP level of theory investigated the complexes' steady-state structures, energies, and charge densities. The intermolecular binding energies was negative, indicating that the reactions of the six complexes proceeded spontaneously. There was strong van der Waals forces and hydrogen bonds between the donor and acceptor, which contributed to the complexes' strong molecular stability. The C N and N H groups in the donor molecule, and the -COOH group in the acceptor molecule, played key roles in the complexation process. DFT calculation results were appropriate to support our experimental results. This study highlights the molecular mechanisms of donor and acceptor action in charge-transfer interactions, providing a theoretical basis for the synthesis of antibiotic complexes and the removal of antibiotics. [Display omitted] [ABSTRACT FROM AUTHOR]

Push-pull chromophores, with strong intramolecular charge transfer (ICT), exhibit high ground-state polarization, driving strong NLO responses. The donor and acceptor abilities of the groups in the investigated compounds influence ICT, so the nonlinear response of these compounds was analyzed in relation to their strength. Two different families of NLOphores were synthesized through [2 + 2] cycloaddition-retroelectrocyclizations of heterocycle-based electron-rich alkynes with tetracyanoethylene (TCNE) and tetracyanoquinodimethane (TCNQ). The λ max values of push-pull chromophores, particularly for charge transfer bands, fall within the range of 424–758 nm. The linear and nonlinear optical properties of these NLOphores were subsequently examined through a combination of experimental and theoretical methods. NLO measurements were conducted using a validated custom-made Z-scan device. The nonlinear absorption coefficients range from −1.44 × 10−4 cm.W−1 to −9.90 × 10−4 cm.W−1, while nonlinear refractive indices range from −1.59 × 10−7 cm2. W−1 to −2.26 × 10−6 cm2. W−1. As expected from their molecular structures, the TCNQ products displayed stronger nonlinear responses than the TCNE products. [Display omitted] • A broad λ max range (424–758 nm) was achieved through the rational design of NLOphores. • NLOphores were successfully synthesized, in high yields (over 90 %), using a simple and atom-economic [2 + 2] CA-RE. • The structures containing diethylaniline and heterocyclic groups exhibited strong NLO responses. • The target NLOphores showed positive solvatochromism, consistent with their ICT characteristics. [ABSTRACT FROM AUTHOR]

[Display omitted] • Metal-organic or coordination complexes are essential absorbers of light energy. • Two classes of absorbers are possible based on charge transfer mechanism. • Complexes with direct charge-transfer mechanism (Type-II) are discussed in-depth. • Applications of these complexes in solar cell are reviewed. • Complexes without pi-electron proximity at coordination interfaces are proposed. Photovoltaics employ absorbers to harness light energy for power generation. One huge class of absorbers is molecular coordination complexes, which are naturally available and can be obtained by synthetic procedures as well. To be used in solar energy harvesting, chemists consider anchoring groups as a crucial component. The anchoring moiety determines the extent of interaction between these complexes and inorganic substrates onto which they are attached in solar cell devices. This introduces several synthetic difficulties and energy loss mechanisms. To solve these issues, a new class of materials known as Type-II absorbers have arisen among chemists. Herein, the absorbers of the useful solar region (visible and infrared spectra) are rather generated after in-situ interactions between high-bandgap organic molecules and the inorganic substrates. This process eliminates non-radiative energy losses and shifts synthetic focus from thermodynamic alignments to interface binding strengths. Dye-sensitized solar cells (DSSCs), which employ these absorbers, can be classified into two types based on the electron transfer mechanism at the photoanode. The conventional one, Type-I, involves a two-step process consisting of light absorption by the dye and the subsequent injection of photoexcited electrons into the conduction band of TiO 2. In contrast, Type-II employs direct single-step injection of excited electrons from the sensitizer. In Type-II, simple molecular sensitizers, rather than complex light-harvesting dyes, directly bind with TiO 2 to form a charge-transfer complex, exhibiting broad-range absorption over 300–800 nm. This range is consistent with a highly effective and direct injection of excited electrons into the semiconducting TiO 2 , hence the designation "coordination complex sensitized solar cells." However, the overall PCE is generally low, primarily due to the fast back-electron transfer (BET) process from the TiO 2 to the oxidized sensitizer. Significant efforts have been devoted to suppressing the BET to enhance the performance of Type-II DSSCs both computationally and experimentally. However, these efforts were limited to using 1,2-benzenediol (catechol) as the backbone for sensitizing molecules, resulting in a PCE still as high as approximately 1 %. Recently, the employment of alternative sensitizers without the catechol backbone has been suggested to reduce the BET, which is often facilitated by the pi-electron system of catechol. In this paper, we examine the trends and various strategies employed to minimize the BET and propose a novel molecular design approach that could ultimately lead to better-performing coordination complex sensitized solar cells in the future. [ABSTRACT FROM AUTHOR]

Induced smectic phases of 5CB-EBBA binary mixtures were investigated with respect to the structures, stabilities, and molecular motion. The highest stability of the ordered smectic phase was obtained when 5CB and EBBA were mixed at 1:2. At the same ratio, the transferred charges between 5CB and EBBA took the maximum, indicating the direct correlation of the induced phase to the charge-transfer interaction. Whereas, the molecular motion monotonically slowed down with increasing EBBA, which is ascribed to the decrease of the free volume. The stability and the slow molecular reorientation may be independently controlled in the induced smectics. [ABSTRACT FROM AUTHOR]