Heteronuclear Ir(III)–Ln(III) Luminescent Complexes: Small-Molecule Probes for Dual Modal Imaging and Oxygen Sensing

Jana, Arundhati; Crowston, Bethany J.; Shewring, Jonathan R.; McKenzie, Luke K.; Bryant, Helen E.; Botchway, Stanley W.; Ward, Andrew; Amoroso, Angelo J.; Baggaley, Elizabeth; Ward, Michael D.

doi:10.1021/acs.inorgchem.6b00702

Cited by 41 publications

(22 citation statements)

References 108 publications

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“…Examples of Ln III complexes with dual properties include magnetic resonance imaging (MRI) contrast agents, which concurrently sense oxygen, and complexes that generate 1 O 2 , which can be tracked simultaneously by MRI or Eu III ‐based emission . For example, porphyrin‐based Ln III complexes emit in the near‐infrared (NIR) with φ 1O2 values in the range 1.5 % to 4.0 %, and a Tb III complex with naphthyl and azaxanthonyl functional groups displays a Tb III ‐centered emission efficiency (φ Tb ) of 24 % and a φ 1O2 of 12 % .…”

Section: Introductionmentioning

confidence: 99%

Wavelength‐Dependent Singlet Oxygen Generation in Luminescent Lanthanide Complexes with a Pyridine‐Bis(Carboxamide)‐Terthiophene Sensitizer

Johnson

Vittardi

Gracia-Nava

et al. 2020

Chemistry A European J

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Lanthanide ion (LnIII) complexes, [Ln(3Tcbx)2]3+ (LnIII=YbIII, NdIII, ErIII) are isolated with a new pyridine‐bis(carboxamide)‐based ligand with a 2,2′:5′,2′′‐terthiophene pendant (3TCbx), and their resulting photophysical properties are explored. Upon excitation of the complexes at 490 nm, only LnIII emission is observed with efficiencies of 0.29 % at 976 nm for LnIII=YbIII and 0.16 % at 1053 nm for LnIII=NdIII. ErIII emission is observed but weak. Upon excitation at 400 nm, concurrent 1O2 formation is seen, with efficiencies of 11 % for the YbIII and NdIII complexes and 13 % for the ErIII complex. Owing to the concurrent generation of 1O2, as expected, the efficiency of metal‐centered emission decreases to 0.02 % for YbIII and 0.05 % for NdIII. The ability to control 1O2 generation through the excitation wavelength indicates that the incorporation of 2,2′:5′,2′′‐terthiophene results in access to multiple sensitization pathways. These energy pathways are unraveled through transient absorption spectroscopy.

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Section: Introductionmentioning

confidence: 99%

Wavelength‐Dependent Singlet Oxygen Generation in Luminescent Lanthanide Complexes with a Pyridine‐Bis(Carboxamide)‐Terthiophene Sensitizer

Johnson

Vittardi

Gracia-Nava

et al. 2020

Chemistry A European J

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“…[9][10][11][12][13][14][15] Such systems have been employed in bioimaging, in particular for in vivo 1 O2 sensing. 16,17 Depending on the nature of the tether between the iridium complexes and other molecules, energy transfers can occur via two different mechanisms: i) Förster energy transfers, which are common in unconjugated tethers but decay exponentially with distance of electron-donating groups which raise the energy of the pic orbitals, thereby reducing their involvement in the frontier orbitals of the complex and properties of the excited state. [36][37][38] In the current investigation, we sought to examine the effects of substituting varied alkynes at different positions ( Figure 1) around pic upon the photophysical properties of the complexes and establish which sites had the greatest effects in creating a pathway for the addition of other functional groups.…”

Section: Introductionmentioning

confidence: 99%

Exploring the Chemistry and Photophysics of Substituted Picolinates Positional Isomers in Iridium(III) Bisphenylpyridine Complexes

et al. 2017

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2017) 'Exploring the chemistry and photophysics of substituted picolinates positional isomers in iridium(III) bisphenylpyridine complexes. ', Organometallics., 36 (15).The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. KEYWORDSPicolinate substitution, molecular building block, iridium, positional difference ABSTRACT: A simple and versatile route for modifying picolinate ligands coordinated to iridium is described. Reacting a µ-chloro iridium(C^N) dimer (where C^N is a phenylpyridine based ligand) with bromopicolinic acid (HpicBr) yields the corresponding iridium(C^N)2(picBr) complexes (1-4 and 11), which were readily modified by a Sonogashira reaction to give eight alkyne-substituted picolinate complexes (5-10, 12 and 13).The luminescent behaviour of these complexes shows that the position of substitution about the picolinate ring has both an effect on photophysical behaviour as well as the reactivity. and rely on dipole-dipole coupling between transition dipole moments of the donor and acceptor; 18 and ii) Dexter energy transfers, which involve the electron exchange between donor and acceptor. tend to favour conjugated tethers, but which can occur over a 20 Å distance between the sensitizer and emitter. 19 The most common approach to joining iridium sensitizers to an emitter is to attach the tether to the ancillary ligand of the iridium complex. This approach is favoured because the conditions required to coordinate the primary ligands are often harsh and lead to ligand exchange, but in contrast, the ancillary ligand coordinating conditions are typically mild, allowing for the ligand to be modified prior (or post) to coordination. The two most modified types of ancillary ligands are acetylacetonate (acac) and diimine ligands (e.g., 1,10phenanthroline [phen] or 2,2ˈ-bipyridine [bpy]). Acetylacetonate has been extensively modified at the beta methyl (β-methyl) positions with an assortment of aromatic and alkyl groups; 20-26 the unoccupied orbitals of acac tend to be high in energy and therefore have little involvement in the photophysics of the complexes. Recently, however, Zeissel et al., by substituting the central position with aromatic groups containing accessible triplet states, have demonstrated that it is possible to introduce an interligand energy transfer. 26,27 Diimine ligands tend to have low-lying π * orbitals, which result in the iridium complexes' lowest unoccupied molecular orbitals (LUMOs) being strongly diimine in character. These have been tethered by a variety of groups including alkanes and napthylene to lanthanide com...

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“…Jana et al prepared dual modal MRI/hypoxia imaging probes based on iridium (III)−lanthanide (III) luminescent complexes. 47 The authors successfully connected a phosphorescent iridium (Ir) unit with one or two lanthanide (Ln, Ln=Eu(III) and Gd(III), respectively) units to synthesize an Ir-Ln metal complex for MRI/luminescent bioimaging. The dinuclear complex had outstanding water solubility, low cytotoxicity, and accurate lysosome staining ability.…”

Section: Multimodal Hypoxia Imaging Nanoparticlesmentioning

confidence: 99%

<p>Multifunctional hypoxia imaging nanoparticles: multifunctional tumor imaging and related guided tumor therapy</p>

Liu¹,

Liu²,

Wu³

2019

IJN

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Hypoxia is a common feature of most solid tumors. Having a comprehensive understanding of tumor hypoxia condition is a key to tumor therapy. Many hypoxia imaging nanoparticles have been used for tumor detection. However, simple optical hypoxia imaging is not enough for tumor diagnosis. Also, the tumor therapy process needs the information about the tumor hypoxia condition. Recently, researchers developed multimodal hypoxia tumor imaging nanoparticles and multifunctional hypoxia imaging-guided tumor therapy nanoparticles. The multimodal hypoxia imaging could produce more tumor region information and engage in functional tumor imaging to better understand the tumor condition. The multifunctional hypoxia imaging-guided tumor therapy could monitor the tumor therapy process and evaluate tumor therapeutic effect. Meanwhile, many challenges and limitations are still remaining in the application of multifunctional hypoxia nanoparticles. In this review, we first introduce the types of multifunctional hypoxia imaging nanoparticles. Then we focus on multimodal hypoxia imaging nanoparticles and hypoxia imaging-guided tumor therapy nanoparticles. We also discuss the challenges and future perspectives of this field. There has not been many studies in this field for now. We hope this review would bring more researchers’ attention to this field so that it would substantially contribute to tumor precise therapy.

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Heteronuclear Ir(III)–Ln(III) Luminescent Complexes: Small-Molecule Probes for Dual Modal Imaging and Oxygen Sensing

Cited by 41 publications

References 108 publications

Wavelength‐Dependent Singlet Oxygen Generation in Luminescent Lanthanide Complexes with a Pyridine‐Bis(Carboxamide)‐Terthiophene Sensitizer

Wavelength‐Dependent Singlet Oxygen Generation in Luminescent Lanthanide Complexes with a Pyridine‐Bis(Carboxamide)‐Terthiophene Sensitizer

Exploring the Chemistry and Photophysics of Substituted Picolinates Positional Isomers in Iridium(III) Bisphenylpyridine Complexes

<p>Multifunctional hypoxia imaging nanoparticles: multifunctional tumor imaging and related guided tumor therapy</p>

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