- Ligand-Sensitized Near-Infrared to Visible Linear Light Upconversion in a Discrete Molecular Erbium Complex
-
While the low-absorption cross section of lanthanide-based upconversion systems, in which the trivalent lanthanides (Ln3+) are responsible for converting low- to high-energy photons, has restricted their application to intense incident light, the emergence of a cascade sensitization through an organic dye antenna capable of broadly harvesting near-infrared (NIR) light in upconversion nanoparticles opened new horizons in the field. With the aim of pushing molecular upconversion within the range of practical applications, we show herein how the incorporation of an NIR organic dye antenna into the ligand scaffold of a mononuclear erbium coordination complex boosts the upconversion brightness of the molecule to such an extent that a low-power (0.7 W·cm-2) NIR laser excitation of [L6Er(hfa)3]+(hfa = hexafluoroacetylacetonate) at 801 nm results in a measurable visible upconverted signal in a dilute solution (5 × 10-4M) at room temperature. Connecting the NIR dye antenna to the Er3+activator in a single discrete molecule cures the inherent low-efficient metal-based excited-state absorption mechanism with a powerful indirect sensitization via an energy transfer upconversion, which drastically improves the molecular-based upconverted Er3+-centered visible emission.
- Alves, Filipe,Golesorkhi, Bahman,Guénée, Laure,Naseri, Soroush,Nozary, Homayoun,Piguet, Claude,Taarit, Inès
-
supporting information
p. 15326 - 15334
(2021/09/30)
-
- Bottom-Up Approach for the Rational Loading of Linear Oligomers and Polymers with Lanthanides
-
The adducts between luminescent lanthanide tris(β-diketonate)s and diimine or triimine ligands have been explored exhaustively for their exceptional photophysical properties. Their formation, stability, and structures in solution, together with the design of extended metallopolymers exploiting these building blocks, remain, however, elusive. The systematic peripheral substitution of tridentate 2,6-bis(benzimidazol-2-yl)pyridine binding units (Lk = L1-L5), taken as building blocks for linear oligomers and polymers, allows a fine-tuning of their affinity toward neutral [Ln(hfa)3] (hfa = hexafluoroacetylacetonate) lanthanide containers in the [LkLn(hfa)3] adducts. Two trends emerge with (i) an unusual pronounced thermodynamic selectivity for midrange lanthanides (Ln = Eu) and (ii) an intriguing influence of remote peripheral substitutions of the benzimidazole rings on the affinity of the tridentate unit for [Ln(hfa)3]. These trends are amplified upon the connection of several tridentate binding units via their benzimidazole rings to give linear segmental dimers (L6) and trimers (L7), which are considered as models for programming linear Wolf-Type II metallopollymers. Modulation of the affinity between the terminal and central binding units in the linear multitridentate ligands deciphers the global decrease of metal-ligand binding strengths with an increase in the length of the receptors (monomer → dimer → trimer → polymer). Application of the site binding model shed light onto the origin of the variation of the thermodynamic affinities: a prerequisite for the programmed loading of a polymer backbone with luminescent lanthanide β-diketonates. Analysis of the crystal structures for these adducts reveals delicate correlations between the chemical bond lengths measured in the solid state (or bond valence parameters) and the metal-ligand affinities operating in solution.
- Besnard, Céline,Guénée, Laure,Mirzakhani, Mohsen,Naseri, Soroush,Nozary, Homayoun,Piguet, Claude
-
supporting information
p. 15529 - 15542
(2021/10/20)
-
- The assembly of "s3N"-ligands decorated with an azo-dye as potential sensors for heavy metal ions
-
An "S3N-ligand azo-dye" conjugate has been synthesised with a view to the development of a sensor for heavy metal ions. Complexation of this system with Ag(i), Hg(ii) and Cu(ii) salts has been investigated and an X-ray structure has been obtained for a Hg(ii) complex. Complexation of the conjugated dye to these metals results in a bathochromic shift in the absorption maximum of the azo dye, an effect which is most pronounced for Cu(ii).
- Rasheed,McDouall,Muryn,Raftery,Vitorica-Yrezabal,Quayle
-
p. 5229 - 5239
(2017/04/27)
-
- Separation of Am (III) by solvent extraction using water-soluble H4tpaen derivatives
-
The water-soluble ligand N,N,N′,N′-tetrakis[(6-carboxypyridin-2-yl)methyl]ethylenediamine (H4tpaen) and its derivatives were synthesized and evaluated for Am/Cm separation by solvent extraction. In this context, different ligands were studied for their possible use as selective back-extraction agents of actinides, especially americium, from an organic TPH phase. The solvent consisted of different extractants mixtures (DMDOHEMA/HDEHP or TODGA/TBP systems) and was preliminarily loaded with trivalent lanthanide and actinide cations. The aim of these new water-soluble agents was to strip americium or curium in an aqueous acidic phase in order to perform their mutual separation while maintaining other cations in the organic phase. A specific ligand bearing n-alkoxy groups connected to the pyridyl rings of H4tpaen showed water solubility slightly enhanced associated with efficient back-extraction properties with the possibility to perform simultaneously inter-group separation of Am (III) from Eu (III), and intra-group separation of Am(III) from Cm(III).
- Gracia, Stéphanie,Arrachart, Guilhem,Marie, Cécile,Chapron, Simon,Miguirditchian, Manuel,Pellet-Rostaing, Stéphane
-
p. 5321 - 5336
(2015/07/15)
-
- Thermal-healable and shape memory metallosupramolecular poly(n-butyl acrylate-co-methyl methacrylate) materials
-
A big challenge in developing stimuli-responsive materials is to integrate multiple functionalities such as shape memory property, healable ability, recyclability into a single-component material. With this purpose, we designed a novel poly(n-butyl acrylate-co-methyl methacrylate) bearing a side group 2,6-bis(1′-methylbenzimidazolyl)pyridine ligand, which is dynamically crosslinked by the metal salt zinc trifluoromethanesulfonate to obtain the metallosupramolecular polymer. The shape recovery and healing is achieved upon application of a thermal or light stimulus due to the specific metal-ligand interactions which not only serve as an "inert" crosslink network at low temperature to produce the shape recovery, but also dissociate at high temperature for healing. The healing rate is quick and the healing efficiently is close to ～90%. the Partner Organisations 2014.
- Wang, Zhenhua,Fan, Wenru,Tong, Rui,Lu, Xili,Xia, Hesheng
-
p. 25486 - 25493
(2014/07/07)
-
- Implementing liquid-crystalline properties in single-stranded dinuclear lanthanide helicates
-
The connection of flexible protodendritic wedges to the bis-tridentate rigid polyaromatic ligand L1 provides amphiphilic receptors L5 and L6; their reduced affinities for complexing trivalent lanthanides (Ln = La, Y, Lu) in organic solvent (by fifteen orders of magnitude!) prevent the formation of the expected dinuclear triple-stranded helicates [Ln2(Lk) 3]6+. This limitation could be turned into an advantage because L1 or L6 can be treated with [Ln(hfac)3] (Hhfac = 1,1,1,5,5,5-hexafluoro-2,4-pentanedione) to give neutral single-stranded [Ln2(Lk)(hfac)6] complexes with no trace of higher-order helicates. Whereas ligands L1 and L5 are not liquid crystals, L6 can be melted above room temperature (41°C) to give a nematic mesophase, and its associated dinuclear helical complex [Y2(L6)(hfac)6] self-organises at the same temperature into a fluidic smectic mesophase. The lipophilic dendritic ligand L6 selectively reacts with trivalent yttrium hexafluoroacetylacetonate (hfac) to give the liquid-crystalline single-stranded dinuclear helicate [Y2(L6)(hfac)6], which self-organises into an SmA mesophase. Copyright
- Terazzi, Emmanuel,Zaim, Amir,Bocquet, Bernard,Varin, Johan,Guenee, Laure,Dutronc, Thibault,Lemonnier, Jean-Francois,Floquet, Sebastien,Cadot, Emmanuel,Heinrich, Benoit,Donnio, Bertrand,Piguet, Claude
-
supporting information
p. 3323 - 3333
(2013/07/26)
-
- Synthesis, structural investigation and computational modelling of water-binding aquafoldamers
-
Detailed studies on water-binding aquafoldamers are presented that illustrate the potential use of the elongated larger aquafoldamers for recognizing larger water clusters of diverse topologies. A novel self-trapping dimerization mode involving two tetramer molecules is proposed, which is consistent with the obtained varying experimental evidences. The Royal Society of Chemistry 2012.
- Zhao, Huaiqing,Ong, Wei Qiang,Fang, Xiao,Zhou, Feng,Hii, Meng Ni,Li, Sam Fong Yau,Su, Haibin,Zeng, Huaqiang
-
scheme or table
p. 1172 - 1180
(2012/03/07)
-
- Encapsulation of conventional and unconventional water dimers by water-binding foldamers
-
Water-binding foldamers have been rarely studied. By orienting both H-bond donors and acceptors toward their interior, two pyridine-derived crescent-shaped folding oligoamides were found to be capable of trapping both conventional and unconventional water dimer clusters in their cavity (～2.5 A radius). In the unconventional water dimer cluster, the two water molecules stay in contact via an unusual H-H interaction (2.25 A) rather than the typical H-bond.
- Ong, Wei Qiang,Zhao, Huaiqing,Fang, Xiao,Woen, Susanto,Zhou, Feng,Yap, Weiliang,Su, Haibin,Li, Sam F. Y.,Zeng, Huaqiang
-
supporting information; scheme or table
p. 3194 - 3197
(2011/08/06)
-
- Synthesis and coordination chemistry of arene soluble 4-alkyl-2,6-bis[(diphenylphosphino)methyl]pyridine N,P,P′-trioxide ligands
-
The trifunctional ligand 2,6-[(C6H5) 2P(O)CH2]2C5H3NO forms stable complexes with trivalent and tetravalent f-element cations and it acts as an effective liquid-liquid extraction reagent when it is dissolved in CHCl3. In a search for more hydrocarbon solvent soluble extraction reagents, derivative ligands having alkyl substituents in the 4-pyridyl ring position, 4-R′-2,6-[(C6H5)2P(O)CH 2]2C5H2NO (R′ = Et, Oct), have been prepared and characterized. A single crystal X-ray diffraction analysis for the Et derivative shows that the ligand molecular structure is closely related to the parent ligand, 2,6-[(C6H5) 2P(O)CH2]2C5H3NO. The coordination chemistry of the ligands with Nd(NO3)3 has been examined, and the molecular structures of two complexes obtained with 1 : 1 and 2 : 1 ligand : metal reactant ratios are reported. The Royal Society of Chemistry 2003.
- Gan, Xin-Min,Paine, Robert T.,Duesler, Eileen N.,Noeth, Heinrich
-
p. 153 - 159
(2007/10/03)
-
- A new efficient method for the preparation of 2,6-pyridinedimethyl ditosylates from dimethyl 2,6-pyridinedicarboxylates
-
We report here an efficient method for the preparation of 2,6- pyridinedimethyl ditosylate and four of its 4-substituted derivatives, two of them have not been reported in the literature. We also describe here a modification of the reported synthesis for chelidonic and chelidamic acids with improved yields and higher purity.
- Horváth, Gy?rgy,Rusa, Cristian,K?nt?s, Zoltán,Gerencsér, János,Huszthy, Péter
-
p. 3719 - 3731
(2007/10/03)
-
