Molecular Design and Synthetic Approaches for the Realization of Multichannel Radiative Decay Pathways in Gold(III) Complexes and Their Applications in Organic Light-Emitting Devices.

A unique class of tridentate diaryltriazine ligand-containing gold(III) complexes with thermally activated delayed fluorescence (TADF) and/or thermally stimulated delayed phosphorescence (TSDP) properties has been designed and synthesized. With a simple structural modification on the coordination of carbazole moiety in the monodentate ligand, a large spectral shift of ∼160 nm (ca. 4900 cm) spanning from sky blue to red emissions has been demonstrated in solid-state thin films.

Thermally activated delayed fluorescence tetradentate ligand-containing gold(III) complexes with preferential molecular orientation and their application in organic light-emitting devices.

A new class of thermally activated delayed fluorescence (TADF) pyridine-/pyrazine-containing tetradentate C^C^N^N gold(III) complexes have been designed and synthesized. Displaying photoluminescence quantum yields (PLQYs) of up to 0.77 in solid-state thin films, these complexes showed at-least a six-fold increase in the radiative decay rate constant () in toluene upon increasing temperature from 210 to 360 K.

Synthesis, structure and photoluminescence of Cu(I) complexes containing new functionalized 1,2,3-triazole ligands.

The reaction of a triazole ligand, 2-(1-1,2,3-triazol-4-yl)pyridine (L1), with 2-bromopyridine afforded three new ligands, 2,2'-(1-1,2,3-triazole-1,4-diyl)dipyridine (L2), 2,2'-(2-1,2,3-triazole-2,4-diyl)dipyridine (L3) and 2,2'-(1-1,2,3-triazole-1,5-diyl)dipyridine (L4). A series of luminescent mononuclear copper(I) complexes of these ligands [Cu(Ln)(P^P)](ClO) [ = 1, P^P = (PPh) (1); = 1, P^P = POP (2); = 2, P^P = (PPh) (3); = 2, P^P = POP (4); = 3, P^P = (PPh) (5); = 3, P^P = POP (6); = 4, P^P = (PPh) (9); = 4, P^P = POP (10)] have been obtained from the reaction of Ln with [Cu(MeCN)]ClO in the presence of PPh and POP. L3 was also found to form dinuclear compounds [Cu(L3)(PPh)](ClO) (7) and [Cu(L3)(POP)](ClO) (8).

An Ir(III) cyclometalate-functionalized molecularly imprinted polymer: photophysics, photochemistry and chemosensory applications.

A luminescent trimethylamine (TMA) sensor, PTMA-Ir, has been designed and synthesized through immobilizing a phosphorescent iridium(III) complex on a TMA-imprinted polymer. Detailed study shows that the quenching of phosphorescence of PTMA-Ir can serve as a reporter for the binding of TMA on the imprinting sites, thus providing a sensitive, selective, and rapid detection of TMA in both aqueous solutions and gaseous states. Loading PTMA-Ir on filter paper produced a deposition T-Ir, the phosphorescence of which is quenched within 5 s upon exposure to TMA vapor with detection limits of 9.

Tetradentate CCNN Ligand-Containing Gold(III) Complexes with Orange to Deep-Red Thermally Activated Delayed Fluorescence (TADF) and Their Application in Organic Light-Emitting Devices.

A new class of thermally activated delayed fluorescence (TADF) tetradentate CCNN ligand-containing gold(III) complexes containing acridinyl moieties has been designed and synthesized. These complexes exhibit orange-red to deep-red emission with photoluminescence quantum yields (PLQYs) of up to 0.76 in solid-state thin films.

Visible Light-Induced Oxidation of Alcohols by a Luminescent Osmium(VI) Nitrido Complex: Evidence for the Generation of PhIO as a Highly Active Oxidant in the Presence of PhIO.

Although alcohols are readily oxidized by a variety of oxidants, their oxidation by metal nitrido complexes is yet to be studied. We report herein visible-light-induced oxidation of primary and secondary alcohols to carbonyl compounds by a strongly luminescent osmium(VI) nitrido complex (). The proposed mechanism involves initial rate-limiting hydrogen-atom transfer (HAT) from the α-carbon of the alcohol to .

Molecularly Imprinted Polymer-Based Luminescent Chemosensors.

Molecularly imprinted polymer (MIP)-based luminescent chemosensors combine the advantages of the highly specific molecular recognition of the imprinting sites and the high sensitivity with the luminescence detection. These advantages have drawn great attention during the past two decades. Luminescent molecularly imprinted polymers (luminescent MIPs) towards different targeted analytes are constructed with different strategies, such as the incorporation of luminescent functional monomers, physical entrapment, covalent attachment of luminescent signaling elements on the MIPs, and surface-imprinting polymerization on the luminescent nanomaterials.

A small molecule M1 promotes optic nerve regeneration to restore target-specific neural activity and visual function.

Axon regeneration is an energy-demanding process that requires active mitochondrial transport. In contrast to the central nervous system (CNS), axonal mitochondrial transport in regenerating axons of the peripheral nervous system (PNS) increases within hours and sustains for weeks after injury. Yet, little is known about targeting mitochondria in nervous system repair.

Multifunctional Luminescent Sensor Based on the Pb Complex Containing a Tetrazolato Ligand.

A series of luminescent Pb complexes, [Pb()] (), [Pb()] (), [Pb()(NO)(HO)] (), [Pb()(Br)(HO)] (), [Pb()(Cl)(HO)] (), and [Pb()(HO)] () have been synthesized by treatment of polydentate tetrazolato ligands with various hydrated Pb salts ( = 2-(1-tetrazol-5-yl)pyridine, = 3-(1-tetrazol-5-yl)isoquinoline, = 6-(1-tetrazol-5-yl)-2,2'-bipyridine, and = 6,6'-bis(1-tetrazol-5-yl)-2,2'-bipyridine). These complexes have been characterized by IR, TGA, and elemental analysis. Their crystal structures have been determined by X-ray crystallography, and the phase purity of bulk samples were further confirmed by PXRD.

Visible light-induced oxidative -dealkylation of alkylamines by a luminescent osmium(vi) nitrido complex.

-Dealkylation of amines by metal oxo intermediates (M[double bond, length as m-dash]O) is related to drug detoxification and DNA repair in biological systems. In this study, we report the first example of -dealkylation of various alkylamines by a luminescent osmium(vi) nitrido complex induced by visible light.

Luminescent monomeric and dimeric Ru(ii) acyclic carbene complexes as selective sensors for NH/amine vapor and humidity.

A new class of luminescent bis(bipyridyl) Ru(ii) pyridyl acyclic carbene complexes with environmentally-sensitive dimerization equilibrium have been developed. Owing to the involvement of the orbitals of the diaminocarbene ligand in the emissive excited state, the phosphorescence properties of these complexes are strongly affected by H-bonding interactions with various H-bonding donor/acceptor molecules. With the remarkable differences in the emission properties of the monomer, dimer, and H-bonded amine adducts together with the change of the dimerization equilibrium, these complexes can be used as luminescent gas sensors for humidity, ammonia, and amine vapors.

Photoredox Catalysis for the Fabrication of Water-Repellent Surfaces with Application for Oil/Water Separation.

Silanization processes with perfluoroalkyl silanes have been demonstrated to be effective in developing advanced materials with many functional properties, including hydrophobicity, water repellency, and self-cleaning properties. However, practical industrial applications of perfluoroalkyl silanes are limited by their extremely high cost. On the basis of our recent work on photoredox catalysis for amidation with perfluoroalkyl iodides, its application for surface chemical modification on filter paper, as an illustrative example, has been developed and evaluated.

Synthesis, structure and reactivity of iridium complexes containing a bis-cyclometalated tridentate C^N^C ligand.

In an effort to synthesize cyclometalated iridium complexes containing a tridentate C^N^C ligand, transmetallation of [Hg(HC^N^C)Cl] (1) (H2C^N^C = 2,6-bis(4-tert-butylphenyl)pyridine) with various organoiridium starting materials has been studied. The treatment of 1 with [Ir(cod)Cl]2 (cod = 1,5-cyclooctadiene) in acetonitrile at room temperature afforded a hexanuclear Ir4Hg2 complex, [Cl(κ2C,N-HC^N^C)(cod)IrHgIr(cod)Cl2]2 (2), which features Ir-Hg-Ir and Ir-Cl-Ir bridges. Refluxing 2 with sodium acetate in tetrahydrofuran (thf) resulted in cyclometalation of the bidentate HC^N^C ligand and formation of trinuclear [(C^N^C)(cod)IrHgIr(cod)Cl2] (3).

Visible light photocatalytic cross-coupling and addition reactions of arylalkynes with perfluoroalkyl iodides.

Visible light photocatalytic cross-coupling and addition reactions of arylalkynes with perfluoroalkyl iodides have been developed. Through slight modifications of the reaction conditions, reactions that are selective for the preparation of the C-C coupling product (perfluoroalkyl alkynes) and the addition products (iodo-perfluoroalkyl substituted alkenes) can be achieved. These reactions work well with different types of alkynes and perfluoroalkyl iodides.

Precious-metal free photocatalytic production of an NADH analogue using cobalt diimine-dioxime catalysts under both aqueous and organic conditions.

The photocatalytic generation of an NADH synthetic analogue, i.e. 1-benzyl-1,4-dihydronicotinamide (1,4-BNAH), has been studied using the cobalt diimino-dioxime complexes and the BF-bridged derivative as catalysts.

Tunable Luminescent Properties of Tricyanoosmium Nitrido Complexes Bearing a Chelating O^N Ligand.

We have recently reported a strongly luminescent osmium(VI) nitrido complex [Os(N)(NO-L)(CN)] [HNO-L = 2-(2-hydroxy-5-nitrophenyl)benzoxazole]. The excited state of this complex readily activates the strong C-H bonds of alkanes and arenes ( , , 40). In this work, we attempted to tune the excited-state properties of this complex by introducing various substituents on the bidentate L ligand.

Field-induced slow magnetic relaxation in low-spin S = 1/2 mononuclear osmium(v) complexes.

Photochemical reactions of (PPh4)[OsVI(N)(L)(CN)3] (NO2-OsN) with piperidine and pyrrolidine afforded two osmium(v) hydrazido compounds, (PPh4)[OsV(L)(CN)3(NNC5H10)] ([PPh4]1) and (PPh4)[OsV(L)(CN)3(NNC4H8)] ([PPh4]2), respectively. Their structures consist of isolated, mononuclear distorted octahedral osmium anions that are well-separated from each other by PPh4+. Their low spin S = 1/2 and L = 1 ground state was confirmed by magnetometry and DFT calculations.

The Important Role of Coordination Geometry on Photophysical Properties of Blue-Green Emitting Ruthenium(II) Diisocyano Complexes Bearing 2-Benzoxazol-2-ylphenolate.

A series of blue-green emitting Ru diisocyano complexes containing 2-benzoxazol-2-ylphenolate (PBO) have been prepared. The complexes were isolated under varied reaction conditions in two isomeric forms, i.e.

Excited State Dynamics of Isocyano Rhenium(I) Phenanthroline Complexes from Time-Resolved Spectroscopy.

The photophysical processes in a series of isocyano Re(I) phenanthroline complexes {[Re(CNR) (CO) (phen)](PF ); n=2, 3, 4, R=2,6-( Pr) C H - or Bu- (n=2)} in acetonitrile have been studied by resonance Raman spectroscopy, transient resonance Raman spectroscopy, and femtosecond / nanosecond transient spectroscopy to elucidate the nature of their electronic transitions and emissive excited state(s). The kinetics of the intersystem crossing, vibrational relaxation and radiative decay of the metal-to-ligand charge transfer {MLCT [dπ(Re)→π*(phen)]} excited state have also been determined.

Electronic Communication in Luminescent Dicyanorhenate-Bridged Homotrinuclear Rhenium(I) Complexes.

A series of cyano-bridged homotrinuclear Re(I) complexes with the general formula of {[Re]'[Re][Re]'} {[Re]' = -[Re(CO)(LL)(X)]; [Re] = -[(NC)Re(CO)(phen)(CN)]-; LL = diimine, diphosphine, or two carbonyl ligands; X = triphenylphosphine or carbonyl ligand} and the corresponding mononuclear complex analogues were synthesized. The structures of most of the trinuclear Re(I) complexes have been determined by X-ray crystallography. The relative orientations of peripheral to central Re(I) units in these structures vary considerably.

Polynuclear Cu(i) and Ag(i) phosphine complexes containing multi-dentate polytopic ligands: syntheses, crystal structures and photoluminescence properties.

A series of polynuclear metal complexes, [Cu2(L1)(PPh3)4](ClO4)2 (1), [Cu3(L2)(PPh3)6](ClO4) (2), [Cu3(L3)(PPh3)6] (3), [Ag2(L1)(PPh3)4](BF4)2 (4), [Ag4(L2)2(PPh3)6] (5) and [Ag3(L3)(PPh3)5] (6), have been obtained from the reactions of the highly conjugated bridging ligands 2,3-bis(2-pyridyl)pyrazine (L1), 2,3-bis(2-tetrazoyl)pyrazine (H2L2) and 2,3-bis(2-tetrazoyl)imidazole (H3L3) with [Cu(MeCN)4]ClO4 and AgBF4, respectively. Their crystal structures have been determined by X-ray crystallography and their photophysical properties have been investigated in detail. Complexes 1 and 3 show photoluminescence in CH2Cl2 solution, while all the complexes exhibit obvious luminescence in the solid state; detailed photophysical studies and density functional theory calculations of these complexes have revealed that their lowest energy absorptions and emissions are predominantly derived from either metal-to-ligand charge-transfer (MLCT) or intraligand (IL) excited states.

Design of Luminescent Isocyano Rhenium(I) Complexes: Photophysics and Effects of the Ancillary Ligands.

Despite the well-reported MLCT [dπ(M) → π*(CNR)] transitions in the isocyano transition metal complexes, emissive complexes with phosphorescence derived from MLCT [dπ(M) → π*(CNR)] were not extensively studied. To provide insights into the design strategy of phosphorescent rhenium(I) complexes with an emissive MLCT [dπ(Re) → π*(CNR)] excited state, a series of pentaisocyano rhenium(I) complexes have been synthesized. In contrast to most of the reported penta- or hexaisocyano rhenium(I) complexes with unsubstituted or alkyl- or monohalo-substituted phenylisocyanide ligands, which only exhibit photoluminescence in 77 K glassy medium, the solutions of all of these complexes were found to show phosphorescence at room temperature.

Sensitive determination of lysozyme by using a luminescent and colorimetric probe based on the aggregation of gold nanoparticles induced by an anionic ruthenate(II) complex.

The negatively charged ruthenate(II) complex [Ru(bpy)(PPh)(CN)] and gold nanoparticles (AuNPs) were used for detecting lysozyme (LYS). The luminescence of the ruthenate(II) complex is quenched by AuNPs, and this induces the aggregation of AuNPs and a color change from red to blue. After addition of lysozyme, the positively charged lysozyme and the negatively charged ruthenate(II) complex bind each other by electrostatic interaction firstly.

Interface Engineering via Photopolymerization-Induced Phase Separation for Flexible UV-Responsive Phototransistors.

Interface engineering has been recognized to be substantially critical for achieving efficient charge separation, charge carrier transport, and enhanced device performance in emerging optoelectronics. Nevertheless, precise control of the interface structure using current techniques remains a formidable challenge. Herein, we demonstrate a facile and versatile protocol wherein in situ thiol-ene click photopolymerization-induced phase separation is implemented for constructing heterojunction semiconductor interfaces.

Coordination Compounds with Photochromic Ligands: Ready Tunability and Visible Light-Sensitized Photochromism.

Photochromic compounds are well-known for their promising applications in many areas. In this context, many different photochromic families have been developed. As the early study of these photochromic compounds was mainly focused on the organic system, their photochromic reactivity was mainly derived from the singlet excited state.