Black phosphorus (BP) has recently drawn attention in photocatalysis for its optical properties. However, limited by the rapid recombination of photogenerated carriers, the use of BP for ...photocatalytic water splitting still remains a huge challenge. Herein, we prepare a black/red phosphorus (BP/RP) hetero‐phase junction photocatalyst by a wet‐chemistry method to promote the interfacial charge separation and thus achieve Z‐scheme photocatalytic water splitting without using sacrificial agents. The Z‐scheme mechanism was confirmed by time‐resolved transient absorption spectroscopy. This work provides a novel insight into the interface design of hetero‐phase junction with atomic precision.
The red and the black: A direct Z‐scheme hetero‐phase junction of black phosphorus/red phosphorus (BP/RP) photocatalyst is prepared by a wet‐chemistry method. As a result of their appropriate band structures with a staggered alignment and perfect phase junction interface, the BP/RP hetero‐phase junctions give efficient separation of photogenerated carriers and achieve Z‐scheme photocatalytic water splitting without using sacrificial agents.
Intramolecular through‐space charge‐transfer (TSCT) excited states have been exploited for developing thermally activated delayed fluorescence (TADF) emitters, but the tuning of excited state ...dynamics by conformational engineering remains sparse. Designed here is a series of TSCT emitters with precisely controlled alignment of the donor and acceptor segments. With increasing intramolecular π–π interactions, the radiative decay rate of the lowest singlet excited state (S1) progressively increased together with a suppression of nonradiative decay, leading to significantly enhanced photoluminescence quantum yields of up to 0.99 in doped thin films. A high‐efficiency electroluminescence device, with a maximum external quantum efficiency (EQE) of 23.96 %, was achieved and maintains >20 % at a brightness of 1000 cd m−2. This work sheds light on the importance of conformation control for achieving high‐efficiency intramolecular exciplex emitters.
The orientations of donor and acceptor have been controlled for the development of thermally activated delayed fluorescence emitters featuring intramolecular through‐space charge‐transfer excited states. With maximized cofacial π–π interactions between the quasiplanar donor and acceptor segments, a substantial enhancement of radiative decay rate together with a suppressed nonradiative decay resulted in an emission efficiency of almost unity.
Photocatalytic hydrogen evolution from pure water is successfully realized by using interstitial P‐doped CdS with rich S vacancies (CdS‐P) as the photocatalyst in the absence of any electron ...sacrificial agents. Through interstitial P doping, the impurity level of S vacancies is located near the Fermi level and becomes an effective electron trap level in CdS‐P, which can change dynamic properties of photogenerated electrons and thus prolong their lifetimes. The long‐lived photogenerated electrons are able to reach the surface active sites to initiate an efficient photocatalytic redox reaction. Moreover, the photocatalytic activity of CdS‐P can be further improved through the loading of CoP as a cocatalyst.
Photocatalytic hydrogen evolution from pure water is realized by CdS‐P. Through interstitial P doping, the impurity level of S vacancies is located near the Fermi level and becomes an effective electron trap level, which can change the dynamics of photogenerated electrons. The long‐lived photogenerated electrons can reach the surface active sites for initiating the photocatalytic reaction.
Self‐assembled functional nanoarchitectures are employed as important nanoscale building blocks for advanced materials and smart miniature devices to fulfill the increasing needs of high materials ...usage efficiency, low energy consumption, and high‐performance devices. One‐dimensional (1D) crystalline nanostructures, especially molecule‐composed crystalline nanostructures, attract significant attention due to their fascinating infusion structure and functionality which enables the easy tailoring of organic molecules with excellent carrier mobility and crystal stability. In this review, we discuss the recent progress of 1D crystalline self‐assembled nanostructures of functional molecules, which include both a small molecule‐derived and a polymer‐based crystalline nanostructure. The basic principles of the molecular structure design and the process engineering of 1D crystalline nanostructures are also discussed. The molecular building blocks, self‐assembly structures, and their applications in optical, electrical, and photoelectrical devices are overviewed and we give a brief outlook on crucial issues that need to be addressed in future research endeavors.
Recent progress in self‐assembled 1D crystalline nanostructures of functional molecules is discussed, with both small‐molecule‐based crystalline nano structures and functional‐polymer self‐assembled 1D nanostructures. The molecular building blocks, the selfassembled structures, and applications in optical, electrical, and photoelectrical devices are overviewed and a brief outlook on crucial issues that need to be addressed in future research endeavors is given .
Herein are described the synthesis, photophysical properties and applications of a series of luminescent cyclometalated AuIII complexes having an auxiliary aryl ligand. These complexes show ...photoluminescence with emission quantum yields of up to 0.79 in solution and 0.84 in thin films (4 wt % in PMMA) at room temperature, both of which are the highest reported values among AuIII complexes. Thermally activated delayed fluorescence (TADF) is the emission origin for some of these complexes. Solution‐processed OLEDs made with these complexes showed sky‐blue to green electroluminescence with external quantum efficiencies (EQEs) of up to 23.8 %, current efficiencies of up to 70.4 cd A−1, and roll‐off of down to 1 %, highlighting the bright prospect of AuIII‐TADF emitters in OLEDs.
Gold glows: Pincer AuIII aryl complexes give intense photoluminescence (PL) with emission quantum yields of up to 0.79 in solution and 0.84 in thin films. Some of them with N‐substituents based on donor–acceptor structures display stronger PL from thermally activated delayed fluorescence (TADF). The OLEDs fabricated with these TADF emitters exhibit high external quantum efficiencies (EQEs) over 23 % (ISC=intersystem crossing).
Structurally robust tetradentate gold(III)‐emitters have potent material applications but are rare and unprecedented for those displaying thermally activated delayed fluorescence (TADF). Herein, a ...novel synthetic route leading to the preparation of highly emissive, charge‐neutral tetradentate C^C^N^C gold(III) complexes with 5‐5‐6‐membered chelate rings has been developed through microwave‐assisted C−H bond activation. These complexes show high thermal stability and with emission origin (3IL, 3ILCT, and TADF) tuned by varying the substituents of the C^C^N^C ligand. With phenoxazine/diphenylamine substituent, we prepared the first tetradentate gold(III) complexes that are TADF emitters with emission quantum yields of up to 94 % and emission lifetimes of down to 0.62 μs in deoxygenated toluene. These tetradentate AuIII TADF emitters showed good performance in vacuum‐deposited OLEDs with maximum EQEs of up to 25 % and LT95 of up to 5280 h at 100 cd m−2.
Gold(III) complexes supported by tetradentate ligands for OLEDs can be prepared under microwave conditions. Depending on the ligand substituents, these complexes exhibit short‐lived thermally activated delayed fluorescence (TADF) with quantum yields of up to 0.94.
A series of palladium(II)–porphyrin complexes that display dual emissions with lifetimes up to 437 μs have been synthesized. Among the four complexes, PdF20TPP is an efficient and robust catalyst for ...photoinduced oxidative CH functionalization by using oxygen as terminal oxidant. α‐Functionalized tertiary amines were obtained in good to excellent yields by light irradiation (λ>400 nm) of a mixture of PdF20TPP, tertiary amine, and nucleophile (cyanide, nitromethane, dimethyl malonate, diethyl phosphite, and acetone) under aerobic conditions. Four examples of intramolecular cyclized amine compounds could be similarly prepared. Comparison of the UV‐visible absorption spectra before and after the photochemical reaction revealed that PdF20TPP was highly robust (>95 % recovery). The practical application of PdF20TPP has been revealed by the photochemical reactions performed by using a low catalyst loading (0.01 mol %) and on a 10 mmol scale. The PdF20TPP catalyst could sensitize photoinduced oxidation of sulfides to sulfoxides in excellent yields. Mechanistic studies revealed that the photocatalysis proceeded by singlet‐oxygen oxidation.
Long‐lived excited states! A series of palladium(II)–porphyrin complexes have been synthesized and found to display long‐lived excited states with lifetimes up to 437 μs (see scheme). Among these complexes, PdF20TPP is an efficient and robust catalyst for a broad array of photoinduced oxidative CH functionalization reactions. PtF20TPP=platinum(II) meso‐tetrakis(2,3,4,5,6‐pentafluorophenyl)porphyrin.
Direct C-H bond functionalization catalyzed by non-precious transition metals is an attractive strategy in synthetic chemistry. Compared with the precious metals rhodium, palladium, ruthenium, and ...iridium commonly used in this field, catalysis based on non-precious metals, especially the earth-abundant ones, is appealing due to the increasing demand for environmentally benign and sustainable chemical processes. Herein, developments in iron- and cobalt-catalyzed C(sp
3
)-H bond functionalization reactions are described, with an emphasis on their applications in organic synthesis,
i.e.
, the synthesis of natural products and pharmaceuticals and/or their modification.
This review highlights the developments in iron and cobalt catalyzed C(sp
3
)-H bond functionalization reactions with emphasis on their applications in organic synthesis,
i.e.
natural products and pharmaceuticals synthesis and/or modification.
Illuminating results: Activation of non‐emissive AuIII(N N N)(NHC)+ complexes (such as 1) through reduction by intracellular glutathione gives active AuI–NHC complexes, which show promising ...anti‐cancer properties, accompanied by release of the highly fluorescent ligand. The high fluorescence “switch‐on” efficiency makes these AuIII complexes excellent probes for cellular thiol detection.
Photonic circuit systems based on optical waveguiding heteroarchitectures have attracted considerable interest owing to their potential to overcome the speed limitation in electronic circuits by ...modulating the optical signal at the micro‐ or nanoscale. However, controlling the parameters, including the wavelength and polarization of the light outcoupling, as well as the sequence among different building blocks, remains a key issue. Herein, supramolecular heteroarchitectures made by phosphorescent organometallic complexes of Pt, Pd, Cu, and Au are applied as photonic logic gates that show continuously variable emission colors from 475 to 810 nm, low waveguide losses down to 0.0077 dB µm−1, and remarkable excitation‐light polarization‐dependent photoluminescence with anisotropy ratios up to 0.68. The sequences among Pt, Pd, Au, and Cu building blocks in the heteroarchitectures are controlled by living supramolecular polymerization or crystallization‐driven self‐assembly synthetic approaches. The results indicate the prospects for using organometallic complexes and supramolecular synthetic approaches to prepare photonic circuit systems with tunable emission color and controllable sequences among different blocks that achieve modulation of the optical signal in the visible‐to‐near‐infrared spectral region.
An input‐to‐output photonic logic gate is fabricated based on supramolecular heterostructures by phosphorescent Pt, Pd, Au, and Cu organometallic complexes. It is based on the optical waveguiding effect and efficient energy transfer among different blocks. The photonic logic gates show high emission anisotropy, low optical waveguiding loss, and continuously varied emission colors in the visible‐to‐near‐infrared spectral region.
