Tetradentate carbene-anilido boron complexes: highly fluorescent dyes with larger Stokes shifts than BODIPY analogues.

A new class of carbene-anilido boron complexes have been designed and synthesized. The complexes show intense fluorescence with large Stokes shift because of their charge-transfer excited states, different from typical BODIPY dyes. By using a chiral 1,1'-bi(2-naphthol) ligand, dyes exhibiting circularly polarized luminescence can also be facilely developed.

Two-Coordinate Gold(I) Complex with Rotational Freedom: A Platform Integrating Thermally Activated Delayed Fluorescence, Polymorphism, and Linearly Polarized Luminescence.

Two-coordinate coinage metal complexes have been exploited for various applications. Herein, a new donor-metal-acceptor (D-M-A) complex PZI-Au-TOT, using bulky pyrazine-fused N-heterocyclic carbene (PZI) and trioxytriphenylamine (TOT) ligands, was synthesized. PZI-Au-TOT displays decent thermally activated delayed fluorescence (TADF) with a quantum yield of 93 % in doped film.

Two-Coordinate Dinuclear Donor-Gold(I)-Acceptor Complexes Exhibiting Multiple Excitation Wavelength Dependent Phosphorescence.

Two-coordinate Au(I) complexes with a donor-metal-acceptor (D-M-A) structure have shown rich luminescent properties. However, charge-neutral dinuclear donor-metal-acceptor type Au(I) complexes featuring aurophilic interactions have been seldom explored. Herein, we describe the structures and photoluminescence properties of two dinuclear Au(I) complexes, namely DiAu-Ph and DiAu-Me.

Iron Corrole-Catalyzed Intramolecular Amination Reactions of Alkyl Azides. Spectroscopic Characterization and Reactivity of [Fe(Cor)(NAd)].

As nitrogen analogues of iron-oxo species, high-valent iron-imido species have attracted great interest in the past decades. Fe-alkylimido species are generally considered to be key reaction intermediates in Fe(III)-catalyzed C(sp)─H bond aminations of alkyl azides but remain underexplored. Here, it is reported that iron-corrole (Cor) complexes can catalyze a wide range of intramolecular C─H amination reactions of alkyl azides to afford a variety of 5-, 6- and 7-membered N-heterocycles, including alkaloids and natural product derivatives, with up to 3880 turnover numbers (TONs) and excellent diastereoselectivity (>99:1 d.

Probing the Electron Accepting Ability of Phosphaphenalenes.

Phosphaphenalenes, extended π conjugates with the incorporation of phosphorus, are attractive avenues towards molecular materials for the applications in organic electronics, but their electron accepting ability have not been investigated. Herein we present systematic studies on the reductive behavior of a representative phosphaphenalene and its oxide by chemical and electrochemical methods. The chemical reduction of the phosphaphenalene by alkali metals reveals the facile P-C bond cleavage to form phosphaphenalenide anion, which functions as a transfer block for structure modification on the phosphorus atom.

Manipulating Chiroptical Activities in 0D Chiral Hybrid Manganese Bromides by Solvent Molecular Engineering.

0D hybrid metal halides (0D HMHs) with fully isolated inorganic units provide an ideal platform for studying the correlations between chiroptical activities and crystal structures at atomic levels. Here, through the incorporation of different solvent molecules, a series of 0D chiral manganese bromides (RR/SS-CHN)MnBr·2X (X = CHOH, CHOH, or HO) are synthesized to elucidate their chiroptical properties. They show negligible circular dichroism signals of Mn absorptions due to C-symmetric [MnBr] tetrahedra.

Polarizability matters in enantio-selection.

The prevalence of chirality, or, handedness in biological world is a fundamental phenomenon and a characteristic hallmark of life. Thus, understanding the origin of enantio-selection, i.e.

Thermally Activated Delayed Fluorescent Binuclear Copper(I) Alkynyl Complexes with Cuprophilic Interactions.

Copper(I)-based thermally activated delayed fluorescence (TADF) emitters have been conceived to be promising candidates for display and lighting applications because of their multifarious structures and strong photoluminescence. Herein a string of binuclear Cu(I) complexes bearing pronounced cuprophilic interactions have been designed and synthesized. [Cu(dppb)(μ-η-C≡C-Ph)] (1 a) and [Cu(dppb)(μ-η-C≡C-PPXZ)] (1 b) display photoluminescence quantum yields of up to 67 % in doped films and solid states via TADF and exhibit reversible bicolor luminescence switching upon mechanical stimuli.

Phosphorescent -Bis(triarylisocyanide) W(0) and Mo(0) Complexes.

Homoleptic W(0) and Mo(0) complexes containing bis(triarylisocyanide) ligands with bulky substituents were synthesized and spectroscopically characterized. Crystallographically determined structures revealed that these complexes are hourglass-like in shape with the tridentate ligands adopting a facial coordination mode to the metal center. These complexes luminesce in fluid solutions and in the solid state.

A stable rhodium-coordinated carbene with a σπ electronic configuration.

Isolable singlet carbenes have universally adopted a σπ electronic state, making them σ-donors and π-acceptors. We present a rhodium-coordinated, cationic cyclic diphosphinocarbene with a σπ ground state configuration. Nuclear magnetic resonance spectroscopy studies show a carbene carbon chemical shift below -30.

An Isolable Radical Anion Featuring a 2-Center-3-Electron π-Bond without a Clearly Defined σ-Bond.

Featuring an extra electron in the π* antibonding orbital, species with a 2-center-3-electron (2c3e) π bond without an underlying σ bond are scarcely known. Herein, we report the synthesis, isolation and characterization of a radical anion salt [K(18-C-6)] {[(HCNDipp) Si] P }⋅ (i.e.

Tunable Yellow to Near-Infrared Fluorescent Boron-Amino-Chelating Complexes with Stokes Shifts >100 nm.

A series of diphenylboron-chelating -substituent 8-aminoquinoline, 5-aminoquinoxaline, and 1-aminophenazine were prepared. They exhibit lowest energy absorption peaks of 444-766 nm, emission peaks of 563-820 nm, and quantum yields of up to 46.5%.

Long-Persistent Circularly Polarized Luminescence from a Host-Guest System Regulated by the Multiple Roles of a Gold(I)-Carbene Motif.

The promotion of intersystem crossing (ISC) is critical for achieving a high-efficiency long-persistent luminescence (LPL) from organic materials. However, the use of a transition-metal complex for LPL materials has not been explored because it can also shorten the emission lifetime by accelerating the phosphorescence decay. Here, we report a new class of LPL materials by doping a monovalent Au-carbene complex into a boron-embedded molecular host.

Organophotocatalysed synthesis of 2-piperidinones in one step via [1 + 2 + 3] strategy.

Six-membered N-containing heterocycles, such as 2-piperidinone derivatives, with diverse substitution patterns are widespread in natural products, drug molecules and serve as key precursors for piperidines. Thus, the development of stereoselective synthesis of multi-substituted 2-piperidinones are attractive. However, existing methods heavily rely on modification of pre-synthesized backbones which require tedious multi-step procedure and suffer from limited substitution patterns.

Circularly polarized chemiluminescence from planar chiral bis(adamantylidene-1,2-dioxetane)s.

Bis(adamantylidene-1,2-dioxetane), upon conjugation to a planar chiral scaffold of [2.2]paracyclophane, gave chemical-triggerable circularly polarized chemiluminescence with a dissymmetry factor of 1.1 × 10 scale, to which exciton chirality upon chemiexcitation was assigned as the origin.

Integrating Achiral and Chiral Organic Ligands in Zero-Dimensional Hybrid Metal Halides to Boost Circularly Polarized Luminescence.

Chiral zero-dimensional hybrid metal halides (0D HMHs) could combine excellent optical properties and chirality, making them promising for circularly polarized luminescence (CPL). However, chiral 0D HMHs with efficient CPL have been rarely reported. Here, we propose an efficient strategy to achieve simultaneously high photoluminescence quantum yield (PLQY) and large dissymmetry factor (g ), by integrating achiral and chiral ligands into 0D HMHs.

Dicationic Diimine Pt(II) Bis(-heterocyclic allenylidene) Complexes: Extended Pt···Pt Chains, NIR Phosphorescence, and Chromonics.

Although square-planar Pt(II) complexes are well-known to self-assemble into supramolecules via noncovalent intermolecular Pt···Pt and/or π-π interactions, the self-assembly of dicationic Pt(II) complexes was scarce due to the electrostatic repulsive force. Herein, a series of dicationic diimine bis(-heterocyclic allenylidene) Pt(II) complexes were synthesized and characterized. Close Pt···Pt and/or π-π contacts are observed in the crystals of these complexes.

Aggregation of phosphorescent Pd(II) and Pt(II) complexes with lipophilic counter-anions in non-polar solvents.

Phosphorescent cationic tridentate C^N^N (HC^N^N = 6-(2-R,4-R-phenyl)-2,2'-bipyridine; R = R = H or F, or R = OMe, R = H) cyclometallated Pd(II) complexes with an ,-dimethyl-imidazol-allenylidene ancillary ligand (L) and their corresponding Pt(II) congeners have been synthesized and characterized, following the previously reported preparation of the complex [Pd(6-phenyl-2,2'-bipyridine)L]. For these cationic Pd(II)/Pt(II) complexes with 2,3,4-tris(dodecyloxy)benzenesulfonate (LA) counter-anions in mixed CHCl/toluene solvents, uniform square flake or fibre-like aggregates were formed. Corresponding multicolour phosphorescence with obvious metal-metal-to-ligand charge transfer (MMLCT) features gradually changed from red to NIR by manipulating the various fractions of Pd/Pt species.

Circularly polarized near-infrared phosphorescence of chiral chromium(III) complexes.

Homoleptic Cr(III) complexes containing anionic tridentate 1,8-(bisoxazolyl)carbazolide ligands are phosphorescent in deaerated solutions with peak maxima in the range of 813-845 nm. The ligand carbon-centred chirality has been transferred to the helical chirality of the complexes and hence induced circularly polarized NIR-emissions with dissymmetry factor in the scale of 2.0 × 10.

The energy gap law for NIR-phosphorescent Cr(III) complexes.

A series of homoleptic Cr(III) complexes containing substituted anionic 1,3-bis(pyridin-2-ylimino)isoindolin-2-ide ligands are phosphorescent with in the 777-970 nm range in degassed fluid solutions. The energy gap law has been successfully applied to the doublet excited states of Cr(III) complexes.

Gold(I) Multi-Resonance Thermally Activated Delayed Fluorescent Emitters for Highly Efficient Ultrapure-Green Organic Light-Emitting Diodes.

Acceleration of singlet-triplet intersystem crossings (ISC) is instrumental in bolstering triplet exciton harvesting of multi-resonance thermally activated delayed fluorescent (MR-TADF) emitters. This work describes a simple gold(I) coordination strategy to enhance the spin-orbit coupling of green and blue BN(O)-based MR-TADF emitters, which results in a notable increase in rate constants of the spectroscopically observed ISC process to 3×10  s with nearly unitary ISC quantum yields. Accordingly, the resultant thermally-stable Au emitters attained large values of delayed fluorescence radiative rate constant up to 1.

Two Cholesterol-Containing Pyrene Derivatives: Subtle Spacer Difference, Diverse Stimuli-Responsive Luminescence, Chirality, and Self-Assembly Behaviors.

Two chiral molecules and were designed and synthesized with a pyrene moiety directly linked to a chiral cholesterol moiety and connected through a methylene spacer, respectively. Influence of the spacer on their stimuli-responsive luminescence, chirality, and self-assembly behaviors was systematically investigated. Molecules and had similar aggregation-induced emission enhancement (AIEE) in solution, because of carrying the same fluorescence moiety.

Highly Efficient Au(I) Alkynyl Emitters: Thermally Activated Delayed Fluorescence and Solution-Processed OLEDs.

Two-coordinate donor-metal-acceptor type coinage metal complexes displaying efficient thermally activated delayed fluorescence (TADF) have been unveiled to be highly appealing candidates as emitters for organic light-emitting diodes (OLEDs). Herein a series of green to yellow TADF gold(I) complexes with alkynyl ligands has been developed for the first time. The complexes exhibit high photoluminescence quantum yields (PLQYs) of up to 0.