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Due to its highly conjugated panel-like structure and unique photophysical and chemical features, anthracene has been widely used for fabricating attractive and functional supramolecular assemblies, including two-dimensional metallacycles and three-dimensional metallacages. The embedded anthracenes in these assemblies often show synergistic effects on enhancing the desired supramolecular and luminescent properties. This review focuses on the metallasupramolecular architectures with anthracene-containing building blocks, as well as their applications in host-guest chemistry, stimulus response, molecular sensing, light harvesting, and biomedical science. [ABSTRACT FROM AUTHOR]

Molecular engineering has emerged as a highly interdisciplinary field of study on function‐directed molecular design, material synthesis, and property optimization, accompanied by a deep understanding of the structure‐property relationship. In this review, our recent progress on the design and preparations of photofunctional metal complexes and related materials is summarized from the perspective of coordination molecular engineering. In particular, a series of cyclometalated diruthenium complexes with near‐infrared (NIR) electrochromic property have been synthesized by engineering the bridging ligand structures. A group of ruthenium‐amine conjugated complexes with multistage NIR electrochromism are obtained on the basis of a multicenter strategy. By engineering the ligand structures, a series of new ruthenium and platinum complexes are synthesized to show switchable luminescence in response to various stimuli. In addition, photoluminescent ruthenium, iridium, and platinum complexes are assembled to afford micro/nanocrystals with well‐defined morphology and luminescent properties. What is the most favorite and original chemistry developed in your research group? Ruthenium‐triarylamine conjugated system is one of my favorite topics. How do you get into this specific field? Molecular materials with multistage redox processes and multiple near‐ infrared absorptions are a challenging task in the field of electrochromism and molecular switching. The combination of cyclometalated ruthenium complexes and triarylamines allows us to solve this issue by using a multicenter strategy with a great structural and functional diversity. What is the most important personality for scientific research? Personally, I consider honesty, curiosity, and persistence are the most important and fundamental personalities in carrying out scientific research. What's your hobbies? I enjoy playing basketball and watching basketball matches in leisure time. How do you keep balance between research and family? I like managing time by prioritizing daily tasks. If time permits, I'm glad to join family activities in cooking, walking, exercising, etc. I always appreciate and support my wife's career and my daughter's studies, from which I receive their returns in support of my career. Could you please give us some advices on improving Chinese Journal of Chemistry? Chin. J. Chem. is a classical and influential journal of chemistry. The impact of the journal keeps increasing especially in recent years. In my point of view, it would be helpful for the journal by keeping a balance among different subjects of chemistry while welcoming manuscripts on material and energy‐related interdisciplinary researches. In addition, in order to further boost its global reputation, I would like to suggest inviting more international scientists to contribute to the journal. [ABSTRACT FROM AUTHOR]

The development of efficient photocathodes is of critical importance for the constructions of promising tandem photo‐electrochemical cells. Most known dye‐sensitized photocathodes are prepared with the conventional carboxylic or phosphonic acid anchors and require the presence of other terminal linking groups to connect catalysts; they suffer from high synthetic difficulty and low adsorption stability in aqueous media. Here, a compact bilayer photocathode has been prepared by using a pyrene‐based photosensitizer with multiple terminal pyridine moieties as both the anchoring and linking groups to connect a Co hydrogen‐evolution catalyst to the NiO substrate. The catalyst and dye molecule are assembled in a layer‐by‐layer manner on NiO through the metal‐pyridine coordination. This photocathode exhibits good dye adsorption stability in aqueous media. A stable cathodic photocurrent of 70 μA cm−2 was achieved, with H2 being generated at the photocathode under the visible‐light irradiation. The Faraday efficiency of H2 evolution was estimated to be 9.1 %. Transient absorption spectral studies suggest that the interfacial hole transfer occurs within a few picoseconds. The integration of the organic photosensitizer with pyridine anchoring and linking groups is expected to provide a simple method for the fabrication of stable and efficient photocathodes. [ABSTRACT FROM AUTHOR]

Abstract: Thermal‐responsive phosphorescent nanotubes have been fabricated from the co‐assembly of two neutral iridium complexes, which behave as the antenna chromophores and energy acceptors, respectively, in these highly ordered crystalline superstructures. By tuning the acceptor doping ratio in a range of 0 to 0.5 %, these tubes display color‐tunable phosphorescence from green to red at room temperature, and it is attributed to the highly efficient light‐harvesting and energy transfer within these materials. For the same reason, the acceptor emission in the nanotubes is amplified more than 800 times with respect to its pure non‐emissive solid sample. The doped tubes show reversible thermal‐responsiveness, in which the energy transfer was completely suppressed at 77 K and reactivated at room temperature. These processes were characterized by the in situ emission color (green, orange, and red) and spectral changes and lifetime measurements of isolated nanotubes. The temperature‐controlled exciton dynamics are responsible for the luminescent thermochromism in these crystalline materials. [ABSTRACT FROM AUTHOR]

Abstract: Thermal‐responsive phosphorescent nanotubes have been fabricated from the co‐assembly of two neutral iridium complexes, which behave as the antenna chromophores and energy acceptors, respectively, in these highly ordered crystalline superstructures. By tuning the acceptor doping ratio in a range of 0 to 0.5 %, these tubes display color‐tunable phosphorescence from green to red at room temperature, and it is attributed to the highly efficient light‐harvesting and energy transfer within these materials. For the same reason, the acceptor emission in the nanotubes is amplified more than 800 times with respect to its pure non‐emissive solid sample. The doped tubes show reversible thermal‐responsiveness, in which the energy transfer was completely suppressed at 77 K and reactivated at room temperature. These processes were characterized by the in situ emission color (green, orange, and red) and spectral changes and lifetime measurements of isolated nanotubes. The temperature‐controlled exciton dynamics are responsible for the luminescent thermochromism in these crystalline materials. [ABSTRACT FROM AUTHOR]

Two bis-tridentate pincer complexes [Ru(H 2 bip)(Mebib)](PF 6 ) 2 ( 1 (PF 6 ) 2 ) and [Ru(H 2 bip)(H 2 bib)](PF 6 ) 2 ( 2 (PF 6 ) 2 ) were prepared and studied, where H 2 bip is 2,6-bis(benzimidazol-2-yl)pyridine, Mebib is the 2-deprotonated 1,3-bis( N -methylbenzimidazol-2-yl)benzene, and H 2 bib is 2-deprotonated 1,3-bis(benzimidazol-2-yl)benzene. These complexes were isolated as cyclometalated Ru(III) salts with a [(NCN)(NNN)] coordination due to a low Ru(III/II) redox potential. Complex 1 (PF 6 ) 2 has two N−H protons on the NNN ligand side, while complex 2 (PF 6 ) 2 has four N−H protons. Absorption spectral analysis showed that two deprotonation steps were distinguished for 1 (PF 6 ) 2 with p K a1 and p K a2 of 3.46 and 5.88, respectively. In comparison, four deprotonation steps were observed for 2 (PF 6 ) 2 with four p K a values of 3.45, 5.95, 8.95, and 10.98, respectively. When the solution was changed from acidic to basic, the Ru(III/II) redox wave of 1 (PF 6 ) 2 and 2 (PF 6 ) 2 shifted from +0.20 V vs Ag/AgCl to a less positive region by 540 and 850 mV, respectively. These studies suggest that the electronic absorption and electrochemical properties of these complexes are very sensitive to pH effect. [ABSTRACT FROM AUTHOR]

Keywords: dibenzo[ f, h ]quinolones; polycyclic aromatic hydrocarbons; C-H arylation; reductive cyclodehydrogenation; ruthenium EN dibenzo[ f, h ]quinolones polycyclic aromatic hydrocarbons C-H arylation reductive cyclodehydrogenation ruthenium 2779 2785 7 08/17/23 20230901 NES 230901 Graph Polycyclic aromatic hydrocarbons (PAHs) typically contain two or more fused benzene rings and are structurally characterized by a high degree of rigidity and -conjugation. We present in this work a new approach to synthesize dibenzo[ I f i , I h i ]quinolines via a two-step procedure involving the ruthenium-catalyzed C-H arylation followed by the potassium-mediated reductive cyclodehydrogenation (Figure 1e). For the substituents, only the relatively electron-rich groups such as OMe, Me, and Ph were used, because electron-deficient substituents, e.g., Cl and CO SB 2 sb Et, are not tolerated in the subsequent reductive cyclodehydrogenation reaction with potassium. Zhang and co-workers developed a palladium-catalyzed double cross-coupling reaction between cyclic diaryliodonium salts and 2-chloropyridinyl acids to access dibenzo-[ I f i , I h i ]quinolines and their derivatives (Figure 1a). [Extracted from the article]

TiO2 photoelectrodes modified with organic dyes with pyridine anchoring groups are prepared, which are used as photoanodes of dye-sensitized photoelectrochemical cells for efficient water reduction with high photocurrent density and stability in aqueous solutions. Vigorous H2 generation with a production rate of around 250 μmol h−1 is realized with a photoanode of an active area of 5 × 5 cm2. [ABSTRACT FROM AUTHOR]

This review summarizes the electronic coupling studies in mixed-valence or donor–acceptor -type complexes containing one or two cyclometalated ruthenium redox sites. Basic electron transfer theories and analysis methods for mixed-valence compounds are introduced, followed by the discussion on the electronic coupling studies of symmetric diruthenium complexes. The effects of the Ru C bond and the position of the Ru C bond on the degree of electronic coupling are highlighted. The uses of different bridging ligands and terminal ligands can greatly modulate the degree of coupling. Complexes with a [NCN-NCN]-type bridging ligand show much stronger electronic coupling with respect to those with a [NNN-NNN]- or [NNC-NNC]-type bridging ligand. In addition, two types of asymmetric complexes are discussed, including redox-asymmetric diruthenium complexes and monoruthenium complexes containing an additional redox-active site. The two-state Hush theory is used to derive the electronic coupling parameters of these complexes. DFT and TDDFT calculations are used to rationalize the spin density distribution and charge transfer transitions of selected odd-electron complexes. Future aspects of the studies on redox-active cyclometalated ruthenium complexes are briefly discussed. [ABSTRACT FROM AUTHOR]

Through Ru(ii)-catalyzed C–H bond activation, a methodology for the synthesis of 2- or 2,7-functionalized pyrene derivatives has been developed using the substrate 1-(pyrid-2-yl)pyrene or 1,6-di(pyrid-2-yl)pyrene. [ABSTRACT FROM AUTHOR]

Bis-triarylamine 2 and cyclometalated diruthenium 6(PF6)2 with a linear trans, trans-urea bridge have been prepared, together with the bis-triarylamine 3 and cyclometalated diruthenium 8(PF6)2 with a folded cis, cis- N, N-dimethylurea bridge. The linear or folded conformations of these molecules are supported by single-crystal X-ray structures of 2, 3, and other related compounds. These compounds display two consecutive anodic redox waves (N .+/0 or RuIII/II processes) with a potential separation of 110-170 mV. This suggests that an efficient electronic coupling is present between two redox termini through the cross-conjugated urea bridge. The degree of electronic coupling has been investigated by using spectroelectrochemical measurements. Distinct intervalence charge-transfer (IVCT) transitions have been observed for mixed-valent (MV) compounds with a linear conformation. The IVCT transitions can also be identified for the folded MV compounds, albeit with a much weaker intensity. DFT results support that the electronic communication occurs by a through-bond and through-space pathway for the linear and folded compounds, respectively. The IVCT transitions of the MV compounds have been reproduced by TDDFT calculations. For the purpose of comparison, a bistriarylamine and a diruthenium complex with an imidazolidin-2-one bridge and a urea-containing mono-triarylamine and monoruthenium complex have been synthesized and studied. [ABSTRACT FROM AUTHOR]

A common bridging ligand, 3,3′,5,5′-tetrakis( N-methylbenzimidazol-2-yl)biphenyl, and four terpyridine terminal ligands with various substituents (amine, tolyl, nitro, and ester groups) have been used to synthesize ten cyclometalated diruthenium complexes 12+- 102+. Among them, compounds 12+- 62+ are redox nonsymmetric, and others are symmetric. These complexes show two RuIII/II processes and an intervalence charge transfer (IVCT) transition in the one-electron oxidized state. The potential separation (Δ E) of 12+- 102+ has been correlated to the energy difference Δ G0, the energy of the IVCT band Eop, and the ground-state delocalization coefficient α2. Time-dependent (TD)DFT calculations suggest that the absorptions in the visible region of 12+- 62+ are mainly associated with the metal-to-ligand charge-transfer transitions from both ruthenium ions and to both terminal ligands and the bridging ligand. However, the energies of these transitions vary significantly. DFT calculations have been performed on 12+- 62+ and 13+- 63+ to give information on the electronic structures and spin populations of the mixed-valent compounds. The TDDFT-predicted IVCT excitations reproduce well the experimental trends in transition energies. In addition, three monoruthenium complexes have been synthesized for a comparison study. [ABSTRACT FROM AUTHOR]

The cyclometalated ruthenium–dipicolylamine(DPA) derivative 3(PF6) has been synthesized.In the presence of1 equiv of Cu2+in an aqueous environment, a new redoxpeak at −0.03 V vs Ag/AgCl appeared. This peak is assignedto the CuII/Iprocess as a result of the complexation ofCu2+with the DPA unit. In the presence of 2 equiv of Cu2+, the metal-to-ligand charge-transfer absorption of 3(PF6) at 516 nm significantly decreased and anew absorption peak at 750 nm appeared. Accordingly, the solutionturned from purple to yellow. The new absorption at 750 nm is assignedto the ligand-to-metal charge-transfer absorption, as a result ofthe oxidation of the ruthenium component by Cu2+. Theseoptical and electrochemical changes have not been observed in thepresence of the other 13 metal ions examined. A single-crystal X-raystructure of 3·Cu·CH3CN·3ClO4has been obtained and usedfor the elucidation of the stepwise recognition mechanism (coordinationfollowed by oxidation), together with the electrochemical and spectroscopicstudies of the two model compounds 2(PF6)and 4with only the ruthenium component or the DPA unit. [ABSTRACT FROM AUTHOR]

A new bridging ligand, 2,3-di(2-pyridyl)-5-phenylpyrazine (dpppzH), has been synthesized. This ligand was designed so that it could bind two metals through a NN-CNN-type coordination mode. The reaction of dpppzH with cis-[(bpy)2RuCl2] (bpy=2,2′-bipyridine) affords monoruthenium complex [(bpy)2Ru(dpppzH)]2+ ( 12+) in 64 % yield, in which dpppzH behaves as a NN bidentate ligand. The asymmetric biruthenium complex [(bpy)2Ru(dpppz)Ru(Mebip)]3+ ( 23+) was prepared from complex 12+ and [(Mebip)RuCl3] (Mebip=bis( N-methylbenzimidazolyl)pyridine), in which one hydrogen atom on the phenyl ring of dpppzH is lost and the bridging ligand binds to the second ruthenium atom in a CNN tridentate fashion. In addition, the RuPt heterobimetallic complex [(bpy)2Ru(dpppz)Pt(CCPh)]2+ ( 42+) has been prepared from complex 12+, in which the bridging ligand binds to the platinum atom through a CNN binding mode. The electronic properties of these complexes have been probed by using electrochemical and spectroscopic techniques and studied by theoretical calculations. Complex 12+ is emissive at room temperature, with an emission λmax=695 nm. No emission was detected for complex 23+ at room temperature in MeCN, whereas complex 42+ displayed an emission at about 750 nm. The emission properties of these complexes are compared to those of previously reported Ru and RuPt bimetallic complexes with a related ligand, 2,3-di(2-pyridyl)-5,6-diphenylpyrazine. [ABSTRACT FROM AUTHOR]

Abstract: This review first summarizes various synthetic approaches to vinyl-substituted polypyridine ligands. Based on the polymerization efficiency of vinyl-substituted complexes and stability of the resulting polymeric films, four categories of substrates are distinguished and representative examples are then given. The characterizations of metallopolymeric films using different electrochemical, spectroscopic, and microscopic methods are introduced. Finally, recent applications of the title films in electrode coatings, electrocatalysis, electrogenerated chemiluminescence, and electrochromism are discussed. [Copyright &y& Elsevier]

A multicenter redox-active system with a linear N--Ru--Ru--N array, where two distal triarylamine sites are bridged by a cyclometalated bisruthenium segment, has been synthesized and characterized with single-crystal X-ray analysis. This system displays four consecutive and separate anodic redox waves at low potentials, indicating the presence of amine--amine electronic coupling with a distance of 19.16 A through the cyclometalated bisruthenium segment In contrast, when a noncyclometalated bisruthenium bridge is used, no amine--amine coupling is present. Upon stepwise oxidation by chemical or electrochemical methods, four-step absorption spectral changes occur in the visible to near-infrared region. In addition, the EPR studies and DFT and TDDFT calculations of the singly oxidized state are presented. [ABSTRACT FROM AUTHOR]

Self-assembled monolayers (SAMs) of either ferrocenecarboxylic acid or 5-(4-Carboxyphenyl)-10,15,20-triphenyl-porphyrin-Co(II) (CoP) with a high- \kappa dielectric were integrated into the Flash memory gate stack. The molecular reduction–oxidation (redox) states are used as charge storage nodes to reduce charging energy and memory window variations. Through the program/erase operations over tunneling barriers, the device structure also provides a unique capability to measure the redox energy without strong orbital hybridization of metal electrodes in direct contact. Asymmetric charge injection behavior was observed, which can be attributed to the Fermi-level pinning between the molecules and the high-\kappa dielectric. With increasing redox molecule density in the SAM, the memory window exhibits a saturation trend. Three programmable molecular orbital states, i.e., \CoP^0, \CoP^1-, and \CoP^2-, can be experimentally observed through a charge-based nonvolatile memory structure at room temperature. The electrostatics is determined by the alignment between the highest occupied or the lowest unoccupied molecular orbital (HOMO or LUMO, respectively) energy levels and the charge neutrality level of the surrounding dielectric. Engineering the HOMO–LUMO gap with different redox molecules can potentially realize a multibit memory cell with less variation. [ABSTRACT FROM PUBLISHER]

Circularly polarized luminescence (CPL)‐active molecular materials have drawn increasing attention due to their promising applications for next‐generation display and optoelectronic technologies. Currently, it is challenging to obtain CPL materials with both large luminescence dissymmetry factor (glum) and high quantum yield (Φ). A pair of enantiomeric N N C‐type Pt(II) complexes (L/D)‐1 modified with chiral Leucine methyl ester are presented herein. Though the solutions of these complexes are CPL‐inactive, the spin‐coated thin films of (L/D)‐1 exhibit giantly‐amplified circularly polarized phosphorescences with |glum| of 0.53 at 560 nm and Φair of ~50 %, as well as appealing circular dichroism (CD) signals with the maximum absorption dissymmetry factor |gabs| of 0.37–0.43 at 480 nm. This superior CPL performance benefits from the hierarchical formation of crystalline fibrillar networks upon spin coating. Comparative studies of another pair of chiral Pt(II) complexes (L/D)‐2 with a symmetric N C N coordination mode suggest that the asymmetric N N C coordination of (L/D)‐1 are favorable for the efficient exciton delocalization to amplify the CPL performance. Optical applications of the thin films of (L/D)‐1 in CPL‐contrast imaging and inducing CP light generation from achiral emitters and common light‐emitting diode lamps have been successfully realized. [ABSTRACT FROM AUTHOR]

Circularly polarized luminescence (CPL)‐active molecular materials have drawn increasing attention due to their promising applications for next‐generation display and optoelectronic technologies. Currently, it is challenging to obtain CPL materials with both large luminescence dissymmetry factor (glum) and high quantum yield (Φ). A pair of enantiomeric N N C‐type Pt(II) complexes (L/D)‐1 modified with chiral Leucine methyl ester are presented herein. Though the solutions of these complexes are CPL‐inactive, the spin‐coated thin films of (L/D)‐1 exhibit giantly‐amplified circularly polarized phosphorescences with |glum| of 0.53 at 560 nm and Φair of ~50 %, as well as appealing circular dichroism (CD) signals with the maximum absorption dissymmetry factor |gabs| of 0.37–0.43 at 480 nm. This superior CPL performance benefits from the hierarchical formation of crystalline fibrillar networks upon spin coating. Comparative studies of another pair of chiral Pt(II) complexes (L/D)‐2 with a symmetric N C N coordination mode suggest that the asymmetric N N C coordination of (L/D)‐1 are favorable for the efficient exciton delocalization to amplify the CPL performance. Optical applications of the thin films of (L/D)‐1 in CPL‐contrast imaging and inducing CP light generation from achiral emitters and common light‐emitting diode lamps have been successfully realized. [ABSTRACT FROM AUTHOR]

The exploration of organic near‐infrared (NIR) luminescence, along with circularly polarized luminescence (CPL), is of vital importance due to its significance in medical and optoelectronic applications. Integrating a chiral unit into a D–A molecular structure in this research realized emission peaks at 744 nm, exhibiting a dissymmetric factor of −1.67 × 10−3. The introduced chiral TPA derivative not only imparts aggregation‐induced emission properties and CPL capabilities but also induces a redshift in the emission spectrum. Consequently, the fabricated NIR organic light‐emitting devices (OLEDs), achieve maximum electroluminescent peaks at 748 nm in nondoped devices with the external quantum efficiency of 13.7% in doped devices. This pioneering research provides inspiration for the design of NIR molecules possessing CPL properties in the future, particularly in promoting the application of intense NIR‐OLEDs. [ABSTRACT FROM AUTHOR]

Recently, chiral metal‐organic coordination materials have emerged as promising candidates for a wide range of applications in chiroptoelectronics, chiral catalysis, and information encryption, etc. Notably, the chiroptical effect of coordination chromophores makes them appealing for applications such as photodetectors, OLEDs, 3D displays, and bioimaging. The direct synthesis of chiral coordination materials using chiral organic ligands or complexes with metal‐centered chirality is very often tedious and costly. In the case of ionic coordination materials, the combination of chiral anions with cationic, achiral coordination compounds through noncovalent interactions may endow molecular materials with desirable chiroptical properties. The use of such a simple chiral strategy has been proven effective in inducing promising circular dichroism and/or circularly polarized luminescence signals. This concept article mainly delves into the latest advances in exploring the efficacy of such a chiral anion strategy for transforming achiral coordination materials into chromophores with superb photo‐ or electro‐chiroptical properties. In particular, ionic small‐molecular metal complexes, metal clusters, coordination supramolecular assemblies, and metal‐organic frameworks containing chiral anions are discussed. A perspective on the future opportunities on the preparation of chiroptical materials with the chiral anion strategy is also presented. [ABSTRACT FROM AUTHOR]

Some new pyridyl alcohols with the cis-bicyclo[3.3.0]octane scaffold were synthesized and used as chiral ligands for the enantioselective addition of diethylzinc to aldehydes. Ligands 4 were found to be far superior to the C2-symmetric ligands 2 in terms of enantioselectivities. Quantitative yields and enantiomeric excesses of up to 92% were obtained when the ligand 4 was used. The carbonyl function in 4 proved to be beneficial for the high enantioselectivities in the addition of diethylzinc to aldehydes. Conversion of the carbonyl group into oxime or oxime ether group led to a sort of more active ligands, which catalyzed the same reaction with rate acceleration. [Copyright &y& Elsevier]

A new category of β-amino alcohols with a bicyclo[3.3.0]octane scaffold has been synthesized and used in the direct asymmetric nitroaldol reaction (Henry reaction). Up to 74% ee was obtained with the addition of nitromethane to relatively bulky aldehydes. [Copyright &y& Elsevier]

Amino alcohols with the bicyclo[3.3.0]octane framework were synthesized, characterized and used as chiral ligands for the addition of diethylzinc to aldehydes. Quantitative yields and enantiomeric excesses of up to 92% were obtained in the ethylation reactions. [Copyright &y& Elsevier]

• A ruthenium polypyridyl complex with 2-picolinamide as an anionic N^N bidentate ligand is presented for the selective recognition of H 2 PO 4 − by spectroscopic and electrochemical response. • In response to the presence of H 2 PO 4 −, the Ru(II/III) redox couple of 4 (PF 6) displays a "two-wave behavior" accompanied by a large negative shift from +0.74 to +0.45 V vs Ag/AgCl. • 1H NMR spectral titration analyses suggest that effective hydrogen-bonding interactions are present between 4 and H 2 PO 4 −, which are believed responsible for the observed spectroscopic and electrochemical response of 4 (PF 6) toward H 2 PO 4 −. A ruthenium polypyridyl complex 4 (PF 6) with 2-picolinamide as an anionic N^N bidentate ligand is synthesized and characterized, including single-crystal X-ray analysis. As an effective anion receptor in CH 2 Cl 2 , complex 4 (PF 6) shows selective spectroscopic and electrochemical recognition towards H 2 PO 4 − over other anions tested (F−, Cl−, Br−, I−, HP 2 O 7 3−, HSO 4 −, AcO− and NO 3 −). Job's plot and mass spectral analyses support that an adduct is formed between 4 and H 2 PO 4 − with a 1:2 binding stoichiometry. The absorption spectral titration of 4 (PF 6) with H 2 PO 4 − yields a global association constant in the order of 108 L2⋅mol−2 and an optical detection limit of 1.4 × 10−6 mol⋅L−1. In response to the presence of H 2 PO 4 −, the Ru(II/III) redox couple of 4 (PF 6) displays a "two-wave behavior" accompanied by a large negative shift from +0.74 to +0.45 V vs Ag/AgCl. 1H NMR spectral titration analyses suggest that effective hydrogen-bonding interactions are present between 4 and H 2 PO 4 −, which are believed responsible for the observed spectroscopic and electrochemical response of 4 (PF 6) toward H 2 PO 4 −. A Ru(II) polypyridyl complex with 2-picolinamide is shown to selectively recognize H 2 PO 4 − by distinct spectroscopic and electrochemical signal changes. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Single‐molecule white‐light and near‐infrared circularly polarized luminescent materials are effective complements to the demonstrated enhancements of visible emission in the high contrast 3D images or organic light‐emitting diodes. In this contribution, two binaphthalene‐containing luminogenic enantiomers (BIT or BITM) with aggregation‐induced emission are synthesized which exhibit circularly polarized luminescence in solution with dissymmetry factors of ±5.0 × 10−3 and ±4.8 × 10−3, respectively. Additionally, the dual‐fluorescence spectra of single‐molecule white emission (CIE: 0.33, 0.34) in toluene solution are observed with (R)/(S)‐BIT in low polarity solvent originating from locally excited and twisted intramolecular charge‐transfer emission. While (R)/(S)‐BITM only shows single NIR luminescence with peaks at 720 nm in powder state. The nondoped OLEDs exhibit high maximum external quantum efficiencies of up to 4.2% with small efficiency roll‐off and NIR electroluminescence peak at 709 nm. [ABSTRACT FROM AUTHOR]

At present, one of the major factors limiting the further improvement of inverted (p‐i‐n) perovskite solar cells (PSCs) is trap‐assisted non‐radiative recombination at the perovskite/electron transporting layer (ETL) interface. Surface passivation with organic ammonium salt is a powerful strategy to improve the performance of PSCs. Herein, an effective method by using propylamine hydroiodide (PAI) and 1,3‐diaminopropane dihydroiodide (PDADI) is reported to modify the perovskite/ETL interface. These two ammonium salts do not form new perovskite but directly passivate the defects on the perovskite surface after annealing. The results show that the PDADI‐modified perovskite films possess a lower surface defect density and less non‐radiative recombination as well as improved charge carrier transport. Based on this strategy, the PDADI‐modified p‐i‐n PSCs deliver an impressive efficiency of 25.09% (certified 24.58%) with an open‐circuit voltage of 1.184 V. Furthermore, the unencapsulated PDADI‐modified PSCs also exhibit good storage stability, retaining 91% of initial PCE at 65 °C in a N2 glove box for 1300 h. This strategy provides an efficient route to fabricate highly efficient and stable inverted p‐i‐n structured PSCs. [ABSTRACT FROM AUTHOR]

Singlet oxygen (1O2), representing an important reactive oxygen species, has promising applications in biomedical, material, and environmental sciences. Photosensitized production of 1O2 using organic dyes is highly desirable and the exploration of highly efficient photosensitizers has received considerable attention. Herein, two tridentate Pt(II) complexes, i.e., cationic 1(PF6) and neutral 2, modified with the ethynylnaphthalimide chromophore, were designed and prepared for the application in 1O2 generation. Spectroscopic studies and computational results suggest that 1(PF6) and 2 display the lowest-energy absorption bands centered at 435–465 nm with the molar extinction coefficients of 0.6–3.2 × 104 M−1 cm−1, originating from the singlet ligand-to-ligand charge transfer (1LLCT) and a mixture of 1LLCT and singlet ligand-centered (LC) transitions, respectively. Moreover, they show similar phosphorescence at 620–640 nm assigned to the Pt-perturbed triplet LC emission of the ethynylnaphthalimide moiety. Thanks to the relatively long phosphorescence lifetimes, these complexes exhibit O2-dependent phosphorescence intensities with good reversibility and stability. They are able to behave as efficient triplet photosensitizers to promote the 1O2 generation with high quantum yields (84–89%). This work indicates that the combination of an organic chromophore with Pt(II) complexes provides an effective method to obtain photosensitizers for 1O2 generation. [ABSTRACT FROM AUTHOR]

Three monoruthenium complexes 1(PF6)2–3(PF6)2 bearing an N(CH3)-bridged ligand have been synthesized and characterized. These complexes have a general formula of [Ru(bpy)2(L)](PF6)2, where L is a 2,5-di(N-methyl-N'-(pyrid-2-yl)amino)pyrazine (dapz) derivative with various substituents, and bpy is 2,2′-bipyridine. The photophysical and electrochemical properties of these compounds have been examined. The solid-state structure of complex 3(PF6)2 is studied by single-crystal X-ray analysis. These complexes show two well-separated emission bands centered at 451 and 646 nm (Δλmax = 195 nm) for 1(PF6)2, 465 and 627 nm (Δλmax = 162 nm) for 2(PF6)2, and 455 and 608 nm (Δλmax = 153 nm) for 3(PF6)2 in dilute acetonitrile solution, respectively. The emission maxima of the higher-energy emission bands of these complexes are similar, while the lower-energy emission bands are dependent on the electronic nature of substituents. These complexes display two consecutive redox couples owing to the stepwise oxidation of the N(CH3)-bridged ligand and ruthenium component. Moreover, these experimental observations are analyzed by computational investigation. [ABSTRACT FROM AUTHOR]

The bottom‐up functionalization of solid surfaces shows increasing importance for a wide range of interdisciplinary applications. Multidentate anchors with more than two contact points can bind to solid surfaces with strong chemisorption, well‐defined upright configuration, and tailored functionality. The surface functionalization using multidentate anchors with three (tripodal), four (quadripodal), or more binding points is summarized herein, with a focus on those beyond classical tripodal anchors. In particular, the molecular design on how to achieve multisite interaction between anchor and substrate and the introduction of functional groups to thin films are discussed. [ABSTRACT FROM AUTHOR]

The development of circularly polarized electroluminescence (CPEL) is currently hampered by the high difficulty and cost in the syntheses of suitable chiral materials and the notorious chirality diminishment issue in electrical devices. Herein, diastereomeric IrIII and RuII complexes with chiral (±)‐camphorsulfonate counteranions are readily synthesized and used as the active materials in circularly polarized light‐emitting electrochemical cells to generate promising CPELs. The addition of the chiral ionic liquid (±)‐1‐butyl‐3‐methylimidazole camphorsulfonate into the active layer significantly improves the device performance and the electroluminescence dissymmetry factors (≈10−3), in stark contrast to the very weak circularly polarized photoluminescence of the spin‐coated films of these diastereomeric complexes. Control experiments with enantiopure IrIII complexes suggest that the chiral anions play a dominant role in the electrically‐induced amplification of CPELs. [ABSTRACT FROM AUTHOR]

The development of circularly polarized electroluminescence (CPEL) is currently hampered by the high difficulty and cost in the syntheses of suitable chiral materials and the notorious chirality diminishment issue in electrical devices. Herein, diastereomeric IrIII and RuII complexes with chiral (±)‐camphorsulfonate counteranions are readily synthesized and used as the active materials in circularly polarized light‐emitting electrochemical cells to generate promising CPELs. The addition of the chiral ionic liquid (±)‐1‐butyl‐3‐methylimidazole camphorsulfonate into the active layer significantly improves the device performance and the electroluminescence dissymmetry factors (≈10−3), in stark contrast to the very weak circularly polarized photoluminescence of the spin‐coated films of these diastereomeric complexes. Control experiments with enantiopure IrIII complexes suggest that the chiral anions play a dominant role in the electrically‐induced amplification of CPELs. [ABSTRACT FROM AUTHOR]

Review: 206 refs. [ABSTRACT FROM AUTHOR]

The studies of long-range electronic communication are hampered by solubility and potential-splitting issues. A 'hybridized redox-asymmetry' method using a combination of organic and inorganic redox species is proposed and exemplified to overcome these two issues. Complexes 1(PF6)-6(PF6) (from short to long in length) with the organic redox-active amine and inorganic cyclometalated ruthenium termini bridged by the para-oligophenylene wire have been prepared. Complex 6 has the longest Ru-amine geometrical distance of 27.85 Å. Complexes 3(PF6) and 4(PF6) show lamellar crystal packing on the basis of a head-to-tail anti-parallelly aligned dimeric structure. Two redox waves are observed for all complexes in the potential region between +0.2 and +0.9 V vs Ag/AgCl. The electrochemical potential splitting is 410, 220, 143, 112, 107, and 105 mV for 1(PF6) through 6(PF6), respectively. Ruthenium (+2) to aminium (N•+) charge transfer transitions have been identified for the odd-electron compounds 12+-62+ by spectroelectrochemical measurements. The electronic communication between amine and ruthenium decreases exponentially with a decay slope of −0.137 Å−1. DFT calculations have been performed to complement these experimental results. [ABSTRACT FROM AUTHOR]

Four bridged cyclometalated diruthenium systems are highlighted in this Frontier article, including strongly-coupled diruthenium complexes with a short phen-1,4-diyl or a planar pyren-2,7-diyl bridge, redox asymmetric diruthenium complexes characterized by different terminal ligands on the two ends, diruthenium complexes with a urea bridge that allows modulating the degree of electronic coupling, and those with a redox-active amine bridge with varying electronic structures. These complexes posess redox couples with low potentials and intense intervalence charge transfer absorptions in the near-infrared region in the one-electron-oxidized mixed-valent state. They are appealing not only for providing a platform for fundamental electron transfer studies but also as molecular materials with multi-stage redox switching properties. [ABSTRACT FROM AUTHOR]

Crystalline materials with appealing luminescent properties are attractive materials for various optoelectronic applications. The in situ bicomponent reaction of 1,2-ethylenedisulfonic acid with 1,4-di(pyrid-2-yl)benzene, 1,4-di(pyrid-3-yl)benzene, or 1,4-di(pyrid-4-yl)benzene affords luminescent crystals with hydrogen-bonded polymeric structures. Variations in the positions of the pyridine nitrogen atoms lead to alternating polymeric structures with either a ladder- or zigzag-type of molecular arrangement. By using a nanoprecipitation method, microcrystals of these polymeric structures are prepared, showing polarized luminescence with a moderate degree of polarization. [ABSTRACT FROM AUTHOR]

Nano‐ and micromaterials with anisotropic photoluminescence and photon transport have widespread application prospects in quantum optics, optoelectronics, and displays. But the nature of the polarization information of the out‐coupled light, with respect to that of the source luminescence, has never been explored in active optical‐waveguiding organic crystals. Herein, three different modes (selective, anisotropic, and consistent) of polarized‐photon out‐coupling are proposed and successfully implemented in a set of 2D organic microcrystals with highly linearly‐polarized luminescence. It is found that the polarization direction and degree of the luminescence out‐coupled through different waveguiding channels can either be essentially retained or distinctly changed with respect to those of the original luminescence, depending on the molecular arrangement and the orientation of transition dipole moments of the crystal. This work demonstrates the promising potential of 2D emissive microcrystals in multi‐channel polarized photon transport. [ABSTRACT FROM AUTHOR]

Nano‐ and micromaterials with anisotropic photoluminescence and photon transport have widespread application prospects in quantum optics, optoelectronics, and displays. But the nature of the polarization information of the out‐coupled light, with respect to that of the source luminescence, has never been explored in active optical‐waveguiding organic crystals. Herein, three different modes (selective, anisotropic, and consistent) of polarized‐photon out‐coupling are proposed and successfully implemented in a set of 2D organic microcrystals with highly linearly‐polarized luminescence. It is found that the polarization direction and degree of the luminescence out‐coupled through different waveguiding channels can either be essentially retained or distinctly changed with respect to those of the original luminescence, depending on the molecular arrangement and the orientation of transition dipole moments of the crystal. This work demonstrates the promising potential of 2D emissive microcrystals in multi‐channel polarized photon transport. [ABSTRACT FROM AUTHOR]

Six cyclometalated diruthenium complexes bridged by 3,3′,5,5′-tetra(pyrid-2-yl)biphenyl have been prepared, in which 12+, 32+, and 52+ are symmetric complexes with different terminal ligands [2,6-bis( N-methylbenzimidazolyl)pyridine (Mebip), 4′-tolyl-2,2′:6′,2″-terpyridine (ttpy), and trimethyl-4,4′,4″-tricarboxylate-2,2′:6′,2″-terpyridine (Me3tctpy), respectively]. Three other complexes with mixed terminal ligands (Mebip-Me3tctpy for 62+; Mebip-ttpy for 72+; ttpy-Me3tctpy for 82+) are structurally nonsymmetric. These complexes display two consecutive Ru(III/II) redox couples between 0.20 and 0.90 V vs. Ag/AgCl, with the potential splitting ranging from 150 (for 52+) to 280 mV (for 62+). The mixed-valent states of these complexes have been generated by stepwise electrolysis. The symmetric complexes show intervalence charge transfer (IVCT) transitions at similar energy ( Eop ≈ 5750 cm-1), with the electronic coupling parameter Vab of 1240, 1220, and 970 cm-1 for 13+, 33+, and 53+, respectively. The nonsymmetric series show significantly different Eop (7600, 5850, and 6650 cm-1 for 63+, 73+, and 83+, respectively) but Vab values that were comparable to that of 13+. DFT and TDDFT calculations have been performed to complement these experimental results. [ABSTRACT FROM AUTHOR]

Conventional square‐planar platinum complexes typically form one‐dimensional assemblies as a result of unidirectional metallophilic and/or π⋅⋅⋅π intermolecular interactions. Organoplatinum(II) complexes with a cruciform shape are presented herein to construct two‐dimensional (2D) microcrystals with full‐color and white phosphorescence. These 2D crystals show unique monocomponent π⋅⋅⋅π stacking, from either the cyclometalating or noncyclometalating ligand, and the bicomponent alternate π⋅⋅⋅π stacking from both ligands along different facet directions. Anisotropic tri‐directional waveguiding is further implemented on a single hexagonal microcrystal. These results demonstrate the great capability of the organoplatinum(II) cruciform as a general platform to fabricate 2D phosphorescent micro‐/nanocrystals for advanced photonic applications. [ABSTRACT FROM AUTHOR]

Conventional square‐planar platinum complexes typically form one‐dimensional assemblies as a result of unidirectional metallophilic and/or π⋅⋅⋅π intermolecular interactions. Organoplatinum(II) complexes with a cruciform shape are presented herein to construct two‐dimensional (2D) microcrystals with full‐color and white phosphorescence. These 2D crystals show unique monocomponent π⋅⋅⋅π stacking, from either the cyclometalating or noncyclometalating ligand, and the bicomponent alternate π⋅⋅⋅π stacking from both ligands along different facet directions. Anisotropic tri‐directional waveguiding is further implemented on a single hexagonal microcrystal. These results demonstrate the great capability of the organoplatinum(II) cruciform as a general platform to fabricate 2D phosphorescent micro‐/nanocrystals for advanced photonic applications. [ABSTRACT FROM AUTHOR]

Recently, the exploration of circularly polarized luminescence (CPL)‐active materials has attracted extensive attention. Herein, a pair of enantiomeric tridentate platinum‐isocyanide complexes (D/L)‐5 decorated with a chiral leucine methyl ester are reported. The enhanced red phosphorescence and amplified CPL of (D/L)‐5 with a luminescent dissymmetric factor up to 0.008 and quantum yield of 67% are achieved via solution‐state aggregation, benefiting from the highly‐ordered nanobelt assembly as revealed by microscopic analyses. On the basis of the temperature‐dependent absorption, 2D NOESY NMR and powder X‐ray diffraction spectral investigations, these nanobelts are proposed to form via the cooperative assembly pathway with a head‐to‐tail molecular stacking. This work provides insight into the mechanism of supramolecular chirality amplification and important information for the design and synthesis of high‐performance CPL‐active materials. [ABSTRACT FROM AUTHOR]

The ordered array of nanovoids innanoporous networks, such ashoneycomb, Kagome, and square, provides a molecular template for theaccommodation of “guest molecules”. Compared with thecommonly studied guest molecules featuring high symmetry evenly incorporatedinto the template, guest molecules featuring lower symmetry are rareto report. Herein, we report the formation of a distinct patternedsuperlattice of guest molecules by selective trapping of guest moleculesinto the honeycomb network of trimesic acid (TMA). Two distinct surfacepatterns have been achieved by the guest inclusion induced adaptivereconstruction of a 2D molecular nanoporous network. The honeycombnetworks can synergetically tune the arrangement upon inclusion ofthe guest molecules with different core size but similar peripheralsgroups, resulting in a trihexagonal Kagome or triangular patterns. [ABSTRACT FROM AUTHOR]

• A bipolar cobalt coordination polymer bearing triphenylamine-pyridine ligand (poly(CoL) n) is reported. • In-cell electropolymerization effectively decreases solubility of poly(CoL) n in organic solution. • Dual-ion storage capability of poly(CoL) n originates from multiple redox sites of monomer. • The poly(CoL) n cathode delivered a high discharge specific capacity of 192.13 mAh/g at 0.05 A/g. • The poly(CoL) n cathode delivered a stable long-term cycling ability over 2000 cycles with 89% capacity retention at 5 A/g. Metal coordination complexes with remarkable redox activity and high working voltage are plagued by their limited specific capacity and sever dissolution problem. A bipolar cobalt-based coordination polymer (CoL) bearing both p-type and n-type active centers was synthesized via the in-situ electropolymerization method with collective merits of multiple redox sites, dual-ion storage capability, and excellent chemical stability. As-prepared electrodes delivered remarkable performances including a high discharge specific capacity of 192.13 mAh/g (at 0.05 A/g), stable cycling over 2000 cycles with 89% capacity retention (at 5A/g), and excellent rate capability. Moreover, the dual-ion storage processes were unveiled by ex-situ Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis. It provides insight to design and synthesis of electropolymerized bipolar electrode for high performance dual-ion batteries. [ABSTRACT FROM AUTHOR]

A polyazine ligand, 5,5′-di(1-butyl-1,2,3-triazol-4-yl)-2,2′-bipyridine(Bu-dtabpyH), has been prepared by a “click” reaction.The treatment of Bu-dtabpyH with [Ru(bpy)2Cl2] affords complex [Ru(bpy)2(Bu-dtabpyH)]2+(bpy= 2,2′-bipyridine), which has been characterized by single-crystalX-ray analysis. The reaction of [Ru(bpy)2(Bu-dtabpyH)]2+with another equivalent of [Ru(bpy)2Cl2] in the presence of AgOTf gives a redox-asymmetric bisrutheniumcomplex, [Ru(bpy)2(Bu-dtabpy)Ru(bpy)2]3+(Bu-dtabpy is the 4-deprotonated form of Bu-dtabpyH), with one rutheniumatom binding to the pyridin-4-yl bridge with a Ru–N bond andthe other with a Ru–C bond. This complex displays two Ru(II/III)redox couples at +0.79 and +1.28 V vs Ag/AgCl. After being transformedinto a mixed-valence species, [Ru(bpy)2(Bu-dtabpy)Ru(bpy)2]4+, by one-electron oxidation, it exhibits a moderatemetal-to-metal charge-transfer band around 1300 nm. Density functionaltheory and time-dependent density functional theory calculations havebeen carried out for the model complex [Ru(bpy)2(Me-dtabpy)Ru(bpy)2]3+and the mixed-valence state [Ru(bpy)2(Me-dtabpy)Ru(bpy)2]4+to complement theseexperimental results, where Me-dtabpy is the 4-deprotonated form of5,5′-di(1-methyl-1,2,3-triazol-4-yl)-2,2′-bipyridine. [ABSTRACT FROM AUTHOR]

Recent investigations on polypyridine transi-tion-metal complexes as potential molecular wires have provided new impetus for these long-studied and well-established systems. Using bridging ligands 2,3-di(2-pyridyl)-5,6-diphenylpyrazine (dpdpz) and 2,3,5,6-tetrakis(2-pyridyl)-pyrazine (tppz), a tetrametallic cyclometalated ruthenium complex has been prepared and characterized, with each metal having one Ru--C bond. The electronic properties of this complex and two known monoruthenium and diruthenium complexes with dpdpz (DPDPZ series) were probed by electrochemical and spectroscopic techniques and compared to the previously reported tppz-based noncyclometalated ruthenium complexes (TPPZ series). The frontier orbital energy levels and electronic structures of the two series have been characterized by density functional theory (DFT) calculations. In accordance with the experimental results, these studies suggest that the DPDPZ series oligomers generally have a narrower energy gap relative to the TPPZ series. In addition, the large energy density of states in longer oligomers suggests the possibility of band-type conduction. The DPDPZ series exhibits red-shifted light absorption with enhanced intensity relative to the TPPZ series congeners. Time-dependent DFT computations have been performed to rationalize the electronic absorption of the DPDPZ series. Oxidative spectroelectrochemical measurements of the DPDPZ tetrametallic complex indicate the presence of intervalence charge-transfer transitions among ruthenium sites. [ABSTRACT FROM AUTHOR]

A series of mononuclear cyclometalated ruthenium complexes with 1,2,4,5-tetrakis(N-methylbenzimidazolyl)benzene have been prepared, where two N-methylbenzimidazoles bind to the metal center and others remain intact. Electronic properties of these complexes were investigated by electrochemical and spectroscopic studies and DFT/TDDFT computations. The RuII/III redox potentials of theses complexes can be modulated by attaching substituents of various electronic natures on the non-cyclometalating ligand. These complexes display enhanced visible light absorption compared to those without two free-standing N-methylbenzimidazolyl units as a result of the three-chromophore effect. [ABSTRACT FROM AUTHOR]

The reaction of 2,3-di(2-pyridyl)-5,6-diphenylpyrazine(dpdpz)with Re(CO)5Cl in acetonitrile or toluene afforded mono-Reand bis-Re complexes [Re(CO)3Cl-dpdpz] and [Re(CO)3Cl-dpdpz-Re(CO)3Cl], respectively. A heterodinuclearcomplex [Ru(bpy)2-dpdpz-Re(CO)3Cl](PF6)2could be prepared by the reaction of [Re(CO)3Cl-dpdpz] with Ru(bpy)2Cl2or the reactionof Re(CO)5Cl with a previously reported mono-Ru complex[Ru(bpy)2-dpdpz](PF6)2in moderateyields. Surprisingly, the reaction of [Re(CO)3Cl-dpdpz]or [Re(CO)3Cl-dpdpz-Re(CO)3Cl] with Ru(tpy)Cl3in the presence of AgOTf both afforded an asymmetric bis-Rucomplex [Ru(tpy)-dpdpz-RuCl(tpy)](PF6)2. Thesolid-state structures of [Re(CO)3Cl-dpdpz-Re(CO)3Cl] and [Ru(tpy)-dpdpz-RuCl(tpy)](PF6)2weredetermined by single-crystal X-ray analysis. The electrochemical,absorption, and emission properties of these compounds were studiedby cyclic voltammetric and spectroscopic analyses. In addition, DFTcalculations were carried out to aid in the interpretation of theseexperimental findings. [ABSTRACT FROM AUTHOR]

The linear bis-cyclometalated Ru(II) complex [(ttpy)Ru(ttabp)Ru(ttpy)]2+was prepared from the oxidative coupling of the monometalliccomplex [(ttpy)Ru(dtab)]+in good yield, where ttpy is4′-tolyl-2,2′:6′,2″-terpyridine, ttabpis 3,3′,5,5′-tetrakis(1-butyl-1H-1,2,3-triazol-4-yl)biphenyl,and dtab is 1,3-bis(1-butyl-1H-1,2,3-triazol-4-yl)benzene.The electronic properties of these two complexes were studied andcompared by electrochemical and spectroscopic methods and DFT/TDDFTcalculations. The complex [(ttpy)Ru(ttabp)Ru(ttpy)]2+showedtwo consecutive RuII/IIIredox waves at +0.34 and +0.51V vs Ag/AgCl with a comproportionation constant Kcof 760. One-electron oxidation of [(ttpy)Ru(ttabp)Ru(ttpy)]2+by electrochemical methods produced the mixed-valent complex[(ttpy)Ru(ttabp)Ru(ttpy)]3+, which exhibited a symmetricintervalence charge transfer band at 1800 nm (νmax= 5550 cm–1, εmax= 5100 M–1cm–1, Δν1/2= 3580 cm–1). The energy and shape of this bandare very similar in the different solvents studied (CH3CN, DMF, CH2Cl2). [(ttpy)Ru(ttabp)Ru(ttpy)]3+was determined to be a class II/III borderline system withthe electronic coupling parameter Hab=530 cm–1. It displayed a metal-centered rhombicEPR signal at 77 K with an isotropic gfactor of2.109 and total ganisotropy of 0.256, which pointsto an appreciable spin distribution on the bridging ligand in additionto the metal centers. [ABSTRACT FROM AUTHOR]

Inorganic cesium lead halide perovskites offer a pathway towards thermally stable photovoltaics. However, moisture‐induced phase degradation restricts the application of hole transport layers (HTLs) with hygroscopic dopants. Dopant‐free HTLs fail to realize efficient photovoltaics due to severe electrical loss. Herein, we developed an electrical loss management strategy by manipulating poly(3‐hexylthiophene) with a small molecule, i.e., SMe‐TATPyr. The developed P3HT/SMe‐TATPyr HTL shows a three‐time increase of carrier mobility owing to breaking the long‐range ordering of "edge‐on" P3HT and inducing the formation of "face‐on" clusters, over 50 % decrease of the perovskite surface defect density, and a reduced voltage loss at the perovskite/HTL interface because of favorable energy level alignment. The CsPbI2Br perovskite solar cell demonstrates a record‐high efficiency of 16.93 % for dopant‐free HTL, and superior moisture and thermal stability by maintaining 96 % efficiency at low‐humidity condition (10–25 % R. H.) for 1500 hours and over 95 % efficiency after annealing at 85 °C for 1000 hours. [ABSTRACT FROM AUTHOR]