61770-88-5Relevant academic research and scientific papers
Two-photon spectroscopy of tungsten(0) arylisocyanides using nanosecond-pulsed excitation
Takematsu, Kana,Wehlin, Sara A. M.,Sattler, Wesley,Winkler, Jay R.,Gray, Harry B.
, p. 13188 - 13193 (2017)
The two-photon absorption (TPA) cross sections (δ) for tungsten(0) arylisocyanides (W(CNAr)6) were determined in the 800-1000 nm region using two-photon luminescence (TPL) spectroscopy. The complexes have high TPA cross sections, in the range 1000-2000 GM at 811.8 nm. In comparison, the cross section at 811.8 nm for tris-(2,2′-bipyridine)ruthenium(ii), [Ru(bpy)3]2+, is 7 GM. All measurements were performed using a nanosecond-pulsed laser system.
Photoredox Catalysis Mediated by Tungsten(0) Arylisocyanides
Fajardo, Javier,Barth, Alexandra T.,Morales, Maryann,Takase, Michael K.,Winkler, Jay R.,Gray, Harry B.
supporting information, p. 19389 - 19398 (2021/11/26)
W(CNAr)6 (CNAr = arylisocyanide) photoreductants catalyze base-promoted homolytic aromatic substitution (BHAS) of 1-(2-iodobenzyl)-pyrrole in deuterated benzene. Moderate to high efficiencies correlate with W(CNAr)6 excited-state reduction potentials upon
Bespoke photoreductants: Tungsten arylisocyanides
Sattler, Wesley,Henling, Lawrence M.,Winkler, Jay R.,Gray, Harry B.
supporting information, p. 1198 - 1205 (2015/02/05)
Modular syntheses of oligoarylisocyanide ligands that are derivatives of 2,6-diisopropylphenyl isocyanide (CNdipp) have been developed; tungsten complexes incorporating these oligoarylisocyanide ligands exhibit intense metal-to-ligand charge-transfer visible absorptions that are red-shifted and more intense than those of the parent W(CNdipp)6 complex. Additionally, these W(CNAr)6 complexes have enhanced excited-state properties, including longer lifetimes and very high quantum yields. The decay kinetics of electronically excited W(CNAr)6 complexes (W(CNAr)6) show solvent dependences; faster decay is observed in higher dielectric solvents. W(CNAr)6 lifetimes are temperature dependent, suggestive of a strong coupling nonradiative decay mechanism that promotes repopulation of the ground state. Notably, W(CNAr)6 complexes are exceptionally strong reductants: [W(CNAr)6]+/W(CNAr)6 potentials are more negative than -2.7 V vs [Cp2Fe]+/Cp2Fe. (Figure Presented).
Generation of powerful tungsten reductants by visible light excitation
Sattler, Wesley,Ener, Maraia E.,Blakemore, James D.,Rachford, Aaron A.,Labeaume, Paul J.,Thackeray, James W.,Cameron, James F.,Winkler, Jay R.,Gray, Harry B.
supporting information, p. 10614 - 10617 (2013/08/23)
The homoleptic arylisocyanide tungsten complexes, W(CNXy)6 and W(CNIph)6 (Xy = 2,6-dimethylphenyl, Iph = 2,6-diisopropylphenyl), display intense metal to ligand charge transfer (MLCT) absorptions in the visible region (400-550 nm). MLCT emission (λmax ≈ 580 nm) in tetrahydrofuran (THF) solution at rt is observed for W(CNXy)6 and W(CNIph)6 with lifetimes of 17 and 73 ns, respectively. Diffusion-controlled energy transfer from electronically excited W(CNIph) 6 (*W) to the lowest energy triplet excited state of anthracene (anth) is the dominant quenching pathway in THF solution. Introduction of tetrabutylammonium hexafluorophosphate, [Bun4N][PF 6], to the THF solution promotes formation of electron transfer (ET) quenching products, [W(CNIph)6]+ and [anth] ?-. ET from*W to benzophenone and cobalticenium also is observed in [Bun4N][PF6]/THF solutions. The estimated reduction potential for the [W(CNIph)6]+/ *W couple is -2.8 V vs Cp2Fe+/0, establishing W(CNIph)6 as one of the most powerful photoreductants that has been generated with visible light.
