Excited State Modulation in Carbene-Metal-Amides to Design Fast and Bright Blue Delayed Fluorescence

Charlotte Riley; Nguyen Le Phuoc; Mikko Linnolahti; Alexander S. Romanov

doi:10.1002/adfm.202505661

Excited State Modulation in Carbene-Metal-Amides to Design Fast and Bright Blue Delayed Fluorescence

Charlotte Riley, Nguyen Le Phuoc, Mikko Linnolahti^*, Alexander S. Romanov^*

^*Corresponding author for this work

Materials Chemistry

Research output: Contribution to journal › Article › peer-review

Abstract

The gold-based carbene-metal-amide (CMA) complexes with a 1,2,3,9-tetrahydro-4H-carbazol-4-one amide (L) have been prepared in good yields and photophysically characterized. The carbonyl-substituted amide donor ligand resulted in a 0.2 eV increase of the locally excited triplet state (³LE), preventing parasitic phosphorescence and enabling a small singlet-triplet energy gap (ΔE_ST) down to 30 meV. The series of deep-blue/green CMA complexes emits light via a thermally active delayed fluorescence mechanism with high radiative rates (k_r) up to 2.4 × 10⁶ s⁻¹. The complex ^CAACAuL represents the first known example of a CMA complex with a keto substituted amide ligand to exhibit deep-blue TADF (λ_max = 450 nm, k_r = 6.7 ×10⁵ s⁻¹) photoluminescence.

Original language	English
Journal	Advanced Functional Materials
DOIs	https://doi.org/10.1002/adfm.202505661
Publication status	Published - 4 Jul 2025

Keywords

amide
carbene
gold
photoluminescence
TADF

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10.1002/adfm.202505661

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title = "Excited State Modulation in Carbene-Metal-Amides to Design Fast and Bright Blue Delayed Fluorescence",

abstract = "The gold-based carbene-metal-amide (CMA) complexes with a 1,2,3,9-tetrahydro-4H-carbazol-4-one amide (L) have been prepared in good yields and photophysically characterized. The carbonyl-substituted amide donor ligand resulted in a 0.2 eV increase of the locally excited triplet state (3LE), preventing parasitic phosphorescence and enabling a small singlet-triplet energy gap (ΔEST) down to 30 meV. The series of deep-blue/green CMA complexes emits light via a thermally active delayed fluorescence mechanism with high radiative rates (kr) up to 2.4 × 106 s−1. The complex CAACAuL represents the first known example of a CMA complex with a keto substituted amide ligand to exhibit deep-blue TADF (λmax = 450 nm, kr = 6.7 ×105 s−1) photoluminescence.",

keywords = "amide, carbene, gold, photoluminescence, TADF",

author = "Charlotte Riley and Phuoc, \{Nguyen Le\} and Mikko Linnolahti and Romanov, \{Alexander S.\}",

note = "Publisher Copyright: {\textcopyright} 2025 The Author(s). Advanced Functional Materials published by Wiley-VCH GmbH.",

year = "2025",

month = jul,

day = "4",

doi = "10.1002/adfm.202505661",

language = "English",

journal = "Advanced Functional Materials",

issn = "1616-301X",

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TY - JOUR

T1 - Excited State Modulation in Carbene-Metal-Amides to Design Fast and Bright Blue Delayed Fluorescence

AU - Riley, Charlotte

AU - Phuoc, Nguyen Le

AU - Linnolahti, Mikko

AU - Romanov, Alexander S.

PY - 2025/7/4

Y1 - 2025/7/4

N2 - The gold-based carbene-metal-amide (CMA) complexes with a 1,2,3,9-tetrahydro-4H-carbazol-4-one amide (L) have been prepared in good yields and photophysically characterized. The carbonyl-substituted amide donor ligand resulted in a 0.2 eV increase of the locally excited triplet state (3LE), preventing parasitic phosphorescence and enabling a small singlet-triplet energy gap (ΔEST) down to 30 meV. The series of deep-blue/green CMA complexes emits light via a thermally active delayed fluorescence mechanism with high radiative rates (kr) up to 2.4 × 106 s−1. The complex CAACAuL represents the first known example of a CMA complex with a keto substituted amide ligand to exhibit deep-blue TADF (λmax = 450 nm, kr = 6.7 ×105 s−1) photoluminescence.

AB - The gold-based carbene-metal-amide (CMA) complexes with a 1,2,3,9-tetrahydro-4H-carbazol-4-one amide (L) have been prepared in good yields and photophysically characterized. The carbonyl-substituted amide donor ligand resulted in a 0.2 eV increase of the locally excited triplet state (3LE), preventing parasitic phosphorescence and enabling a small singlet-triplet energy gap (ΔEST) down to 30 meV. The series of deep-blue/green CMA complexes emits light via a thermally active delayed fluorescence mechanism with high radiative rates (kr) up to 2.4 × 106 s−1. The complex CAACAuL represents the first known example of a CMA complex with a keto substituted amide ligand to exhibit deep-blue TADF (λmax = 450 nm, kr = 6.7 ×105 s−1) photoluminescence.

KW - amide

KW - carbene

KW - gold

KW - photoluminescence

KW - TADF

UR - https://www.scopus.com/pages/publications/105009771828

U2 - 10.1002/adfm.202505661

DO - 10.1002/adfm.202505661

M3 - Article

AN - SCOPUS:105009771828

SN - 1616-301X

JO - Advanced Functional Materials

JF - Advanced Functional Materials

ER -

Excited State Modulation in Carbene-Metal-Amides to Design Fast and Bright Blue Delayed Fluorescence

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Keywords

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