Water-soluble, luminescent iridium(iii)–ytterbium(iii) complexes using dipyrido[3,2-a:2′,3′-c]phenazine derivatives as bridging units

Jones, Jennifer E.; Jenkins, Robert L.; Hicks, Robin S.; Hallett, A. J. Hughes; Pope, Simon J. A.

doi:10.1039/c2dt31115a

Cited by 27 publications

(19 citation statements)

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“…The emission maxima for complexes 3a-g show very little variation (627-630 nm), are broad and featureless, and typically characteristic of MLCT-based transitions. 24 This variation is less than that predicted by TD-DFT (see ESI †), possibly suggesting a diminished diimine contribution to the excited state. Corresponding excitation spectra showed that the complexes could be excited up to a wavelength of ca.…”

Section: Papermentioning

confidence: 81%

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Cyclometalated cinchophen ligands on iridium(iii): towards water-soluble complexes with visible luminescence

et al. 2013

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Eight cationic heteroleptic iridium(III) complexes, [Ir(epqc) 2 (N^N)] + , were prepared in high yield from a cyclometalated iridium bridged-chloride dimer bearing two ethyl-2-phenylquinoline-4-carboxylate (epqc) ligands. Two X-ray crystallographic studies were undertaken on selected complexes (where the ancillary ligand N^N = 4,4'-dimethyl-2,2'-bipyridine and 4,7-diphenyl-1,10-phenanthroline) each confirming the proposed formulations, showing an octahedral coordination at Ir(III). In general, the complexes are luminescent (620-630 nm) with moderately long lifetimes indicative of phosphorescence. Hydrolysis of the ethyl ester moieties of the epqc ligands gave the analogous cinchophen-based complexes, which were water-soluble and visibly luminescent (568-631 nm). The spectroscopic and redox characterisation of the complexes was complemented by DFT and TD-DFT calculations, supporting the assignment of dominant 3 MLCT to the emissive character. † Electronic supplementary information (ESI) available: Data collection parameters for the crystallographic studies, electrochemical data for 3a-h, pictorial representations of the calculated frontier orbitals for 3a-h and 4a-h and Cartesian coordinates obtained from DFT calculations. CCDC 907280 and 907282.

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Section: Papermentioning

confidence: 81%

“…The product was used in subsequent reaction without further purification. 24 [Ir(epqc) 2 (bpy)]PF 6 3a.…”

Section: Synthesismentioning

confidence: 99%

Cyclometalated cinchophen ligands on iridium(iii): towards water-soluble complexes with visible luminescence

et al. 2013

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“…Various types of lanthanide(III) complexes attached with Ir(III) complexes have also been reported (Fig. 8f) [82][83][84][85] . Generally, Ir(III) complexes show blue, green, and red luminescence at room temperature based on the MLCT transition bands.…”

Section: Light and Transition Metal Complexesmentioning

confidence: 91%

Effective photosensitized, electrosensitized, and mechanosensitized luminescence of lanthanide complexes

2018

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The 4f-4f emission of Tb(III), Eu(III), and Sm(III) complexes plays an important role in the design of monochromatic green, red, and deep-red luminescent materials for displays, lighting, and sensing devices. The 4f-4f emission of Yb(III), Nd(III), and Er(III) complexes is observed in the near-infrared (IR) region for bioimaging and security applications. However, their absorption coefficients are extremely small (ε < 10 L mol −1 cm −1 ). In this review, photosensitized luminescent lanthanide(III) complexes containing organic chromophores (ligands) with large absorption coefficients (ε > 10,000 L mol −1 cm −1 ) are introduced. Organic molecular design elements, including (1) the control of the excited triplet (T 1 ) state, (2) the effects on the charge-transfer (CT) band, and (3) the energy transfer from metal ions for effective photosensitized luminescence, are explained. The characteristic electrosensitized luminescence (electroluminescence) and mechanoluminescence (triboluminescence) of lanthanide(III) complexes are also explained. Lanthanide(III) complexes with well-designed organic molecules are expected to open avenues of research among the fields of chemistry, physics, electronics, and material science.

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“…By choosing ligands judiciously, it is possible to tune the T1 energy of the iridium complex in such that it is sufficiently above the lanthanide D0, allowing for a photo-induced energy transfer. [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.…”

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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Water-soluble, luminescent iridium(iii)–ytterbium(iii) complexes using dipyrido[3,2-a:2′,3′-c]phenazine derivatives as bridging units

Cited by 27 publications

References 71 publications

Cyclometalated cinchophen ligands on iridium(iii): towards water-soluble complexes with visible luminescence

Cyclometalated cinchophen ligands on iridium(iii): towards water-soluble complexes with visible luminescence

Effective photosensitized, electrosensitized, and mechanosensitized luminescence of lanthanide complexes

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

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