Employing Long-Range Inductive Effects to Modulate Metal-to-Ligand Charge Transfer Photoluminescence in Homoleptic Cu(I) Complexes

Inorganic Chemistry, Journal Year: 2023, Volume and Issue: 62(7), P. 3248 - 3259

Published: Feb. 7, 2023

Four Cu(I) bis(phenanthroline) photosensitizers formulated from a new ligand structural motif (Cu1-Cu4) coded according to their 2,9-substituents were synthesized, structurally characterized, and fully evaluated using steady-state time-resolved absorption photoluminescence (PL) measurements as well electrochemistry. The 2,9-disubstituted-3,4,7,8-tetramethyl-1,10-phenanthroline ligands feature the following six-membered ring systems prepared through photochemical synthesis: 4,4-dimethylcyclohexyl (1), tetrahydro-2H-pyran-4-yl (2), tetrahydro-2H-thiopyran-4-yl (3), 4,4-difluorocyclohexyl (4). Universally, these metal-to-ligand charge transfer (MLCT) chromophores display excited-state lifetimes on microsecond time scale at room temperature, including three longest-lived homoleptic cuprous phenanthroline excited states measured date in de-aerated CH2Cl2, τ = 2.5-4.3 μs. This series of molecules also high PL quantum efficiencies (ΦPL 5.3-12% CH2Cl2). Temperature-dependent lifetime experiments confirmed that all exhibit reverse intersystem crossing thermally activated delayed 1MLCT state lying slightly above 3MLCT state, 1050-1490 cm-1. Ultrafast conventional transient originates MLCT which remains sterically arrested, preventing an excessive flattening distortion even when dissolved Lewis basic CH3CN. Combined electrochemical data provided evidence Cu1-Cu4 are highly potent photoreductants (Eox* -1.73 -1.62 V vs Fc+/0 CH3CN), whose potentials altered solely based heteroatoms or substituents resident 2,9-appended derivatives. It is proposed long-range electronic inductive effects responsible for systematic modulation observed spectra, lifetimes, ground spectra redox potentials. quantitatively follow energy gap law, correlating with related phenanthrolines shown triplet photosensitize 9,10-diphenylanthracene bimolecular rate constants ranging 1.61 2.82 × 108 M-1 s-1. ability tailor both photophysical properties imposed by 2,9-ring platforms advocates directions future chromophore discovery.

Language: Английский

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S-Scheme-Heterojunction LaNiO₃/CdLa₂S₄ Photocatalyst for Solar-Driven CO₂-to-CO Conversion

ACS Applied Nano Materials, Journal Year: 2023, Volume and Issue: 6(10), P. 8927 - 8936

Published: May 9, 2023

Visible-light-driven semiconductor-catalyzed CO2 conversion into valuable chemicals and industrial feedstocks is one of the superior pathways to address excess carbon emissions energy shortages. Herein, an innovative step-scheme (S-scheme) heterojunction assembled from bulk CdLa2S4 surface rare-earth perovskite-type oxide LaNiO3 with precisely engineered suitable band alignment employed for selective photocatalytic CO. The optimized 8%-LaNiO3/CdLa2S4 photocatalyst exhibits outstanding CO output up 102.43 μmol h–1 a selectivity about 83.4%, rivaling all similar incumbent reaction systems CO2-to-CO conversion. It highlights effectiveness S-scheme LaNiO3/CdLa2S4 in hindering recombination photogenerated electron–hole pairs. Meanwhile, remarkable apparent quantum efficiency (AQE) as high 6.76% achieved, well still maintained at 99.5% initial value after five cycle tests, revealing repeatability reliability solar-to-chemical In addition, experimentally verified alignment-boosted mechanism proposed. This study construction structurally flexible highly designable heterojunctions, demonstrating potential application carbon-negative

Language: Английский

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Orange Light-Driven C(sp²)–C(sp³) Cross-Coupling via Spin-Forbidden Ir(III) Metallaphotoredox Catalysis

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(36), P. 19925 - 19931

Published: Aug. 29, 2023

We report the development and characterization of a library Ir(III) photocatalysts capable undergoing spin-forbidden excitation (SFE) under orange light irradiation (595 nm). These catalysts were successfully applied to construction synthetically valuable C(sp2)-C(sp3) bonds inaccessible with existing methods low-energy light-driven dual nickel/photoredox catalysis, demonstrating synthetic utility this photocatalyst family. The are accessing both oxidatively reductively activated coupling partners, illustrated through deaminative arylation potassium alkyl trifluoroborate cross-coupling reactions aryl halides. demonstrate diverse substrate scopes paradigms mild conditions in first example metallaphotoredox coupling.

Language: Английский

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First‐Row d⁶ Metal Complex Enables Photon Upconversion and Initiates Blue Light‐Dependent Polymerization with Red Light

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(43)

Published: Sept. 8, 2023

Photosensitizers for sensitized triplet-triplet annihilation upconversion (sTTA-UC) often rely on precious heavy metals, whereas coordination complexes based abundant first-row transition metals are less common. This is mainly because long-lived triplet excited states more difficult to obtain 3d particularly when the d-subshell only partially filled. Here, we report first example of sTTA-UC a 3d6 metal photosensitizer yielding an performance competitive with metal-based analogues. Using newly developed Cr0 featuring equally good photophysical properties as OsII benchmark complex in combination acetylene-decorated anthracene annihilator, red-to-blue achievable. The efficiency under optimized conditions 1.8 %, and excitation power density threshold reach strong limit 5.9 W/cm2 . These factors, along high photostability, permit initiation acrylamide polymerization by red light, radiative energy transfer between delayed annihilator fluorescence blue light absorbing photo-initiator. Our study provides proof-of-concept photon elusive analogues widely employed d6 photosensitizers, their application photochemical reactions triggered wavelengths close near-infrared.

Language: Английский

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Recent advancements in the molecular design of deep-red to near-infrared light-absorbing photocatalysts

Chem Catalysis, Journal Year: 2024, Volume and Issue: 4(8), P. 100973 - 100973

Published: April 17, 2024

Language: Английский

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