Synthesis and photoluminescence properties of heteroleptic Eu3+, Tb3+ and Tm3+ complexes

Accorsi, Gianluca; Armaroli, Nicola; Cardinali, François; Wang, Dong; Zheng, You‐Xuan

doi:10.1016/j.jallcom.2009.06.096

Cited by 10 publications

(7 citation statements)

References 39 publications

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“…[18][19][20][21][22][23][24] Despite the impressive number of papers related to carbazole-and terpyridine-based organic and inorganic photoactive systems, only a limited number of reports deal with molecules, metal complexes or materials in which these two widely exploited subunits are combined. [25][26][27][28][29][30][31][32] In this context, we decided to take advantage of the complementary electron donor (D, Cbz) and acceptor (A, Tpy) character of these two subunits and prepare D-p-A conjugated systems 33,34 in which carbazole and terpyridine are linked through a phenylene bridge directly attached to the Tpy unit. D-p-A molecules are utilized for different applications in materials science including nonlinear optics and fluorescent probes, just to mention the most frequent.…”

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confidence: 99%

Carbazole-terpyridine donor–acceptor luminophores

et al. 2013

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With the aim to combine two versatile molecular units that are widely utilized in materials and coordination chemistry, bischromophoric electron donor-acceptor carbazole-terpyridine systems (Cbz-Tpy) have been synthesized and characterized. The connecting bridge between the two moieties is constituted by phenylene (1), methylene phenylene (2) and ethynylene phenylene (3), which allow tuning of the intercomponent electronic interactions. Electrochemical studies evidence that oxidation and reduction processes occur on the Cbz and Tpy units, respectively, suggesting the possibility of internal charge transfer states located at about 3.10 eV, which is confirmed by photophysical investigations. The absorption spectra of 1 and 3 show a tail above 300 nm, indicating that these conjugated systems exhibit low-energy transitions with charge-transfer character, as confirmed by theoretical studies. At 298 K, 1-3 show a complex pattern of fluorescence profiles as a function of solvent (toluene, dichloromethane, acetonitrile), often with double emissions attributed to transitions localized on individual chromophores or associated to internal charge-transfer processes. The variability of the spectral position affords multiple colours, including white (e.g. 3 in acetonitrile). Definitive rationalization and assignment of transitions of 1-3 is obtained through singlet and triplet luminescence spectra at 77 K and by means of DFT and TD-DFT methods using the hybrid functional PBE0 and the long range corrected functional CAM-B3LYP with the polarizable continuum model. This work opens the route to versatile materials based on the Tpy-Cbz motif exhibiting luminescence all across the visible spectral region that can be controlled through electronic conjugation, solvent polarity, temperature, functionalization and cation binding.

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Carbazole-terpyridine donor–acceptor luminophores

et al. 2013

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“…The quantum yield of R-1 is nearly 3 times that of R-2, and is also larger than those of reported mononuclear analogues with centrosymmetric structures. 20 Meanwhile, the quantum yield of R-2 is comparable with triple-stranded dinuclear β-diketonate Eu(III) complexes in solution (5%). 21 The decay curves for R-1 and R-2 were monitored within the 5 D 0 → 7 F 2 emission (Fig.…”

Section: Photophysical Propertiesmentioning

confidence: 96%

Two mono- and dinuclear Eu(iii) enantiomeric pairs based on chiral bis-bidentate bridging ligands: synthesis, structures, luminescent and ferroelectric properties

Gao

Xie

et al. 2012

Dalton Trans.

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Using the enantiomeric bis-bidentate bridging ligands (+)/(-)-2,5-bis(4,5-pinene-2-pyridyl)pyrazine (L(S)/L(R)) and depending on the ratio control of reactants, two mono- and dinuclear Eu(III)-based enantiomeric pairs with the formulae Eu(dbm)(3)L(R/S)·2H(2)O (L(R) in R-1, L(S) in S-1 and dbm = dibenzoylmethanato) and Eu(2)(dbm)(6)L(R/S)·H(2)O (L(R) in R-2 and L(S) in S-2) have been stereoselectively synthesized and structurally characterized. The circular dichroic (CD) spectra confirmed their chiroptical activities and enantiomeric natures. The homochiral dinuclear species represents the first example of a polynuclear lanthanide β-diketonate complexes with circular dichroic and crystallographic evidences. The photoluminescent properties studies revealed that both mono- and dinuclear Eu(iii) complexes exhibited the characteristic red emissions of Eu(III) ions in the solid state (at 77 K and 300 K) and CH(2)Cl(2) solution. Notably, the photophysical properties of the mononuclear enantiomers were superior to the dinuclear species. Interestingly, R-2 displayed a ferroelectric property at room temperature, which was not observed for R-1 due to the lack of crystalline polarity. R/S-2 are the first examples of homochiral polynuclear lanthanide complexes with luminescence and ferroelectric properties, being potential multifunctional materials.

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Section: Introductionmentioning

confidence: 99%

“…A vast number of derivatives containing carbazole or terpyridine units can be found in the literature, but relatively few reports on compounds carrying both units separated by a π-conjugated system. [42][43][44][45][46][47] Therefore, there is room for developing new carbazole-terpyridine derivatives with enhanced optoelectronic features, also to widen our knowledge on the relationship between the structure and the electronic properties. [48] Our earlier work carried out on this type of molecules showed that the absorption and emission properties of carbazole-terpyridine dyads can be finely tuned by changing the spacers between the two terminal subunits.…”

Section: Introductionmentioning

confidence: 99%

Carbazole‐Terpyridine Donor‐Acceptor Dyads with Rigid π‐Conjugated Bridges

et al. 2019

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A series of molecules in which 9H‐carbazole (electron donor, D) and 2,2′:6′,2′′‐terpyridine (electron acceptor, A) are connected through rigid π‐conjugated bridges (D‐π‐A systems) have been synthesized and their photophysical properties examined in detail, with the support of DFT calculations. The bridges are made of different sequences of ethynylene, phenylene, and anthracene groups. The synthetic strategies involve condensation of 2‐acetylpyridine with the aromatic aldehyde moiety on different functionalized π‐conjugated bridges and couplings with carbazole derivatives. The system incorporating anthracene in the bridge shows the typical absorption and emission fingerprints of this polycyclic hydrocarbon. The other systems have HOMOs and LUMOs centred, respectively, over the carbazole and the bridge and exhibit solvatochromic charge‐transfer (CT) luminescence with high photoluminescence yield up to 70 %, except when an ethynylene unit is directly attached to the carbazole ring, due to a trans‐bent non‐emissive π–σ* excited state.

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Synthesis and photoluminescence properties of heteroleptic Eu3+, Tb3+ and Tm3+ complexes

Cited by 10 publications

References 39 publications

Carbazole-terpyridine donor–acceptor luminophores

Carbazole-terpyridine donor–acceptor luminophores

Two mono- and dinuclear Eu(iii) enantiomeric pairs based on chiral bis-bidentate bridging ligands: synthesis, structures, luminescent and ferroelectric properties

Carbazole‐Terpyridine Donor‐Acceptor Dyads with Rigid π‐Conjugated Bridges

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