Assembly of Hydrophobic Shells and Shields around Lanthanides

Magennis, Steven W.; Parsons, Simon; Pikramenou, Zoe

doi:10.1002/1521-3765(20021216)8:24<5761::aid-chem5761>3.0.co;2-h

Cited by 97 publications

(99 citation statements)

References 49 publications

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“…The excitation maximum of Eu (III)-Cyclen-TNB complex is at 340 nm and the emission maximum of the hypersensitive 5 D 0 -7 F 2 transition is recorded at 614 nm. The emission band centered at 614 nm ( 5 D 0 -7 F 2 ) obviously higher than those located at 593 nm ( 5 D 0 -7 F 1 ), and 692 nm ( 5 D 0 -7 F 4 ) [48][49][50]. As common for lanthanide complexes the Stokes' shift is large (about 276 nm).…”

Section: Uv-vis and Luminescence Spectroscopysupporting

confidence: 82%

Sensing of nucleosides, nucleotides and DNA using luminescent Eu complex by normal and time resolved fluorescence techniques

Azab

Anwar

Kamel

et al. 2016

Journal of Luminescence

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Section: Uv-vis and Luminescence Spectroscopysupporting

confidence: 82%

Sensing of nucleosides, nucleotides and DNA using luminescent Eu complex by normal and time resolved fluorescence techniques

Azab

Anwar

Kamel

et al. 2016

Journal of Luminescence

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“…A literature procedure was adapted for the isolation of dppa. 32 Toluene (30 mL), chlorodiphenylphosphine (3.30 mL, 18.4 mmol), and hexamethyldisilazane (1.92 mL, 9.23 mmol) were added sequentially to a 100 mL three-necked round-bottom flask inside a glovebox. Upon the addition of hexamethyldisilazane, a white precipitate began to form.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

Assembly, Structure, and Reactivity of Cu₄S and Cu₃S Models for the Nitrous Oxide Reductase Active Site, Cu_Z*

2014

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Bridging diphosphine ligands were used to facilitate the assembly of copper clusters with single sulfur atom bridges that model the structure of the Cu(Z)* active site of nitrous oxide reductase. Using bis(diphenylphosphino)amine (dppa), a [Cu(I)4(μ4-S)] cluster with N-H hydrogen bond donors in the secondary coordination sphere was assembled. Solvent and anion guests were found docking to the N-H sites in the solid state and in the solution phase, highlighting a kinetically viable pathway for substrate introduction to the inorganic core. Using bis(dicyclohexylphosphino)methane (dcpm), a [Cu(I)3(μ3-S)] cluster was assembled preferentially. Both complexes exhibited reversible oxidation events in their cyclic voltammograms, making them functionally relevant to the Cu(Z)* active site that is capable of catalyzing a multielectron redox transformation, unlike the previously known [Cu(I)4(μ4-S)] complex from Yam and co-workers supported by bis(diphenylphosphino)methane (dppm). The dppa-supported [Cu(I)4(μ4-S)] cluster reacted with N3(-), a linear triatomic substrate isoelectronic to N2O, in preference to NO2(-), a bent triatomic. This [Cu(I)4(μ4-S)] cluster also bound I(-), a known inhibitor of Cu(Z)*. Consistent with previous observations for nitrous oxide reductase, the tetracopper model complex bound the I(-) inhibitor much more strongly and rapidly than the substrate isoelectronic to N2O, producing unreactive μ3-iodide clusters including a [Cu3(μ3-S)(μ3-I)] complex related to the [Cu4(μ4-S)(μ2-I)] form of the inhibited enzyme.

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“…This short bond length is indicative of a degree of electron delocalisation around the binding unit, and is consistent to those found for other imidodiphosphinate type ligands. [30] The proton is disordered between the two oxygen atoms and hydrogen bonding occurs between pairs of ligand molecules related by inversion, with an O1···O1' distance of 2.43 (Figure 1 left). The two molecules also interact through p-p contact between rings separated by approximately 3-4 , although they are not parallel; the dihedral angle being 14.768.…”

Section: Tpip and [Ln-mentioning

confidence: 99%

Fully Fluorinated Imidodiphosphinate Shells for Visible‐ and NIR‐Emitting Lanthanides: Hitherto Unexpected Effects of Sensitizer Fluorination on Lanthanide Emission Properties

Glover

Bassett

Nockemann

et al. 2007

Chemistry A European J

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168

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In this paper we demonstrate that the effect of aromatic C--F substitution in ligands does not always abide by conventional wisdom for ligand design to enhance sensitisation for visible lanthanide emission, in contrast with NIR emission for which the same effect coupled with shell formation leads to unprecedented long luminescence lifetimes. We have chosen an imidodiphosphinate ligand, N-{P,P-di(pentafluorophinoyl)}-P,P-dipentafluorophenylphosphinimidic acid (HF20tpip), to form ideal fluorinated shells about all visible- and NIR-emitting lanthanides. The shell, formed by three ligands, comprises twelve fully fluorinated aryl sensitiser groups, yet no-high energy X--H vibrations that quench lanthanide emission. The synthesis, full characterisation including X-ray and NMR analysis as well as the photophysical properties of the emissive complexes [Ln(F20tpip)3], in which Ln=Nd, Sm, Eu, Gd, Tb, Dy, Er, Yb, Y, Gd, are reported. The photophysical results contrast previous studies, in which fluorination of alkyl chains tends to lead to more emissive lanthanide complexes for both visible and NIR emission. Analysis of the fluorescence properties of the HF20tpip and [Gd(F20tpip)3] reveals that there is a low-lying state at around 715 nm that is responsible for partially quenching of the signal of the visible emitting lanthanides and we attribute it to a pi-sigma* state. However, all visible emitting lanthanides have long lifetimes and unexpectedly the [Dy(F20tpip)3] complex shows a lifetime of 0.3 ms, indicating that the elimination of high-energy vibrations from the ligand framework is particularly favourable for Dy. The NIR emitting lanthanides show strong emission signals in powder and solution with unprecedented lifetimes. The luminescence lifetimes of [Nd(F20tpip)3], [Er(F20tpip)3] and [Yb(F20tpip)3] in deuteurated acetonitrile are 44, 741 and 1111 micros. The highest value observed for the [Yb(F20tpip)3] complex is more than half the value of the Yb ion radiative lifetime.

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Assembly of Hydrophobic Shells and Shields around Lanthanides

Cited by 97 publications

References 49 publications

Sensing of nucleosides, nucleotides and DNA using luminescent Eu complex by normal and time resolved fluorescence techniques

Sensing of nucleosides, nucleotides and DNA using luminescent Eu complex by normal and time resolved fluorescence techniques

Assembly, Structure, and Reactivity of Cu₄S and Cu₃S Models for the Nitrous Oxide Reductase Active Site, Cu_Z*

Fully Fluorinated Imidodiphosphinate Shells for Visible‐ and NIR‐Emitting Lanthanides: Hitherto Unexpected Effects of Sensitizer Fluorination on Lanthanide Emission Properties

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Assembly of Hydrophobic Shells and Shields around Lanthanides

Cited by 97 publications

References 49 publications

Sensing of nucleosides, nucleotides and DNA using luminescent Eu complex by normal and time resolved fluorescence techniques

Sensing of nucleosides, nucleotides and DNA using luminescent Eu complex by normal and time resolved fluorescence techniques

Assembly, Structure, and Reactivity of Cu4S and Cu3S Models for the Nitrous Oxide Reductase Active Site, CuZ*

Fully Fluorinated Imidodiphosphinate Shells for Visible‐ and NIR‐Emitting Lanthanides: Hitherto Unexpected Effects of Sensitizer Fluorination on Lanthanide Emission Properties

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Assembly, Structure, and Reactivity of Cu₄S and Cu₃S Models for the Nitrous Oxide Reductase Active Site, Cu_Z*