Luminescent tungsten(vi) complexes as photocatalysts for light-driven C-C and C-B bond formation reactions.

The realization of photocatalysis for practical synthetic application hinges on the development of inexpensive photocatalysts which can be prepared on a large scale. Herein an air-stable, visible-light-absorbing photoluminescent tungsten(vi) complex which can be conveniently prepared at the gram-scale is described. This complex could catalyse photochemical organic transformation reactions including borylation of aryl halides, such as aryl chloride, reductive coupling of benzyl bromides for C-C bond formation, reductive coupling of phenacyl bromides, and decarboxylative coupling of redox-active esters of alkyl carboxylic acid with high product yields and broad functional group tolerance.

Strongly Luminescent Tungsten Emitters with Emission Quantum Yields of up to 84 %: TADF and High-Efficiency Molecular Tungsten OLEDs.

Metal-TADF (thermally activated delayed fluorescence) emitters hold promise in the development of next generation light-emitting materials for display and lighting applications, examples of which are, however, largely confined to Cu and recently Au , Ag , and Au emitters. Herein is described the design strategy for an unprecedented type of metal-TADF emitter based on inexpensive tungsten metal chelated with Schiff base ligand that exhibit high emission quantum yields of up to 56 % in solutions and 84 % in thin-film (5 wt % in 1,3-bis(N-carbazolyl)benzene, mCP) at room temperature. Femtosecond time-resolved emission (fs-TRE) spectroscopy and DFT calculations were undertaken to decipher the TADF properties.

Strongly Luminescent Cyclometalated Gold(III) Complexes Supported by Bidentate Ligands Displaying Intermolecular Interactions and Tunable Emission Energy.

A series of charge-neutral Au complexes, which comprise a dicarbanionic C-deprotonated biphenyl ligand and bidentate ancillary ligands ([Au(C^C)(L^X)]; L^X=β-diketonate and relatives (O^O), quinolinolate and relatives (N^O), and diphosphino (P^P) ligands), were prepared. All the complexes are emissive in degassed CH Cl solutions and in thin-film samples with Φ up to 18 and 35 %, respectively, except for 5 and 6, which bear (N^O)-type ancillary ligands. Variation of the electronic characteristics of the β-diketonate ancillary ligand was demonstrated to be a viable route for tuning the emission color from blue-green (peak λ at ca.

The interplay between fluorescence and phosphorescence with luminescent gold(i) and gold(iii) complexes bearing heterocyclic arylacetylide ligands.

The photophysical properties of a series of gold(i) [LAu(C[triple bond, length as m-dash]CR)] (L = PCy (), RNC (), NHC ()) and gold(iii) complexes [Au(C^N^C)(C[triple bond, length as m-dash]CR)] () bearing heterocyclic arylacetylide ligands with narrow band-gap are compared. The luminescence of both series are derived from an intraligand transition localized on the arylacetylide ligand (ππ*(C[triple bond, length as m-dash]CR)) but displayed prompt fluorescence ( = 2.7-12.

Metal-organic framework composites with luminescent gold(iii) complexes. Strongly emissive and long-lived excited states in open air and photo-catalysis.

The encapsulation of luminescent gold(iii) complexes by metal-organic frameworks (MOFs) lays the groundwork for new phosphorescent materials with activities that are not readily achieved by the host MOF materials or gold(iii) complexes alone. In this work, strong phosphorescence with lifetimes of up to ∼50 μs in open air at room temperature has been achieved by incorporation of cationic cyclometalated gold(iii) complexes into MOFs with anionic frameworks to form Au@MOFs. The Au@MOFs display solid state two-photon-induced phosphorescence.

Theoretical studies on the photophysical properties of luminescent pincer gold(iii) arylacetylide complexes: the role of π-conjugation at the C-deprotonated [C^N^C] ligand.

We have performed theoretical analyses of the photophysical properties of a series of cyclometalated gold(iii) arylacetylide complexes, [(C^N^C)AuC[triple bond, length as m-dash]CPh-4-OMe], with different extents of π-conjugation at the doubly C-deprotonated [C^N^C] ligand replacement of one of the phenyl moieties in the non-conjugated C^N^C ligand () by a naphthalenyl () or a fluorenyl moiety ( and ; HC^N^CH = 2,6-diphenylpyridine). Conforming to the conventional wisdom that extended π-conjugation imposes rigidity on the structure of the IL(ππ*(C^N^C)) excited state (IL = intraligand), the calculated Huang-Rhys factors for the IL → S transition follow the order: > > ∼ , which corroborates the experimental non-radiative decay rate constants, : ≫ > , but not . Density Functional Theory (DFT) calculations revealed that there is an additional triplet excited state minimum of LLCT character (LLCT = ligand-to-ligand charge transfer; [π(C[triple bond, length as m-dash]CPh-4-OMe) → π*(C^N^C)]) for complexes and .

Color tunable organic light-emitting devices with external quantum efficiency over 20% based on strongly luminescent gold(III) complexes having long-lived emissive excited states.

Gold(III) complexes supported by C-deprotonated fluorene-C^N^C ligands having high emission quantum yield up to 0.61 and long-lived emissive excited states are used as yellow emitters in color tunable PLEDs and OLEDs. High EQEs of 13.