Synthetically Tunable White-, Green-, and Yellow-Green-Light Emission in Dual-Luminescent Gold(I) Complexes Bearing a Diphenylamino-2,7-fluorenyl Moiety

Abstract

The syntheses and photophysical characterization of five new gold(I) complexes bearing diphenylamine-substituted fluorenyl moieties are reported; four are characterized by X-ray diffraction crystallography. Ancillary ligation on gold(I) is provided by organophosphine and N-heterocyclic carbene ligands. Two complexes, Au-DPA0 and Au-DPA1, are σ-aryls, two, Au-ADPA0 and Au-ADPA1, are σ-alkynyls, and one, Au-TDPA1, is a σ-triazolyl bound through carbon. All complexes show vibronically structured absorption and luminescence bands that are assignable to π−π* transitions localized on the diphenylamine-substituted fluorenyl π system. The excited-state dynamics of all five chromophores are governed by selection of the ancillary ligand and σ attachment of the diphenylamine-substituted fluorenyl moiety. All of these chromophores are dual luminescent in a toluene solution at 298 K. The luminescence from the aryl derivatives, Au-ADPA0 and Au-DPA1, appears green. The alkynyl derivative containing a phosphine ancillary ligand, Au-ADPA0, is a white-light emitter, while the alkynyl derivative containing an N-heterocyclic carbene ancillary ligand, Au-ADPA1, is a yellow-light emitter. The luminescence from the triazolyl-linked chromophore, Au-TDPA1, appears as yellow-green. Spin-restricted density functional theory calculations support the assignments of ligand-centric optical transitions but with contributions of ligand-to-metal charge transfer involving the vacant Au 6p orbital.

Encapsulation of AIEgens within Metal–Organic Framework toward High‐Performance White Light‐Emitting Diodes

“…The detailed synthetic routes were shown in Schemes S1 and S2, Supporting Information. The chemical structures were well confirmed by nuclear magnetic resonance (NMR) spectroscopy including 1 H NMR, 13 C NMR, 19 F NMR, electrospray-ionization mass spectroscopy (MS) data (Figures S1-S8, Supporting Information) as well as the X-ray single-crystal diffraction analysis (Figures S9 and S10, Supporting Information). Emission spectra of MOTPO and TPEPy in both solution and aggregation states were investigated.…”

“…[5] Another approach, which directly utilizes single-phase white light emitting (WLE) materials excited by ultraviolet light, can overcome the above weaknesses and achieve reproducible and color-stable WLEDs (Approach II in Scheme 1). [6] So far, a series of white-light-coated materials such as small organic molecules, [7][8][9][10] rare earth metals, [11][12][13] carbon dots, [14,15] quantum dots, [16,17] and metal complexes, [11,18,19] have been developed. Among them, organic dyes whose luminescence properties are easier to be adjusted have attracted tremendous attention.…”

Observation of long-lived phosphorescence in Au(i) complexes bearing chromophoric (N-heterocyclic carbene) ligands

“…Absorption of IDPA-AuBr sets in at 400 nm and peaks at 367 nm. The IDPA-AuBr absorption spectrum is similar in band shape and energy to 9,9-diethyl-2diphenylaminofluorene, 39,40 indicating that the absorption transition is an IDPA-localized π-π* transition. Absorption of IBTF-AuBr begins near 375 nm, maximizes at 346 nm, and displays vibronic structure.…”

Intra- vs Intermolecular Aurophilic Contacts in Dinuclear Gold(I) Compounds: Impact on the Population of the Triplet Excited State

“…Gold­(I) is known to display the highest spin–orbit coupling of the d-block metals, , and as a consequence, it can be used as a promotor of phosphorescent emission − due to the enhancement of the intersystem crossing transitions (S 1 → T 1 and T 1 → S 0 ). Once the triplet state is populated, phosphorescence emission can be observed when the excitons decay through efficient radiative T 1 → S 0 pathways.…”