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Photodynamic therapy (PDT) ideally relies on the administration, selective accumulation and photoactivation of a photosensitizer (PS) into diseased tissues. In this context, we report a new heavy-atom-free fluorescent G-quadruplex (G4) DNA-binding PS, named DBI. We reveal by fluorescence microscopy that DBI preferentially localizes in intraluminal vesicles (ILVs), precursors of exosomes, which are key components of cancer cell proliferation. Moreover, purified exosomal DNA was recognized by a G4-specific antibody, thus highlighting the presence of such G4-forming sequences in the vesicles. Despite the absence of fluorescence signal from DBI in nuclei, light-irradiated DBI-treated cells generated reactive oxygen species (ROS), triggering a 3-fold increase of nuclear G4 foci, slowing fork progression and elevated levels of both DNA base damage, 8-oxoguanine, and double-stranded DNA breaks. Consequently, DBI was found to exert significant phototoxic effects (at nanomolar scale) toward cancer cell lines and tumor organoids. Furthermore, in vivo testing reveals that photoactivation of DBI induces not only G4 formation and DNA damage but also apoptosis in zebrafish, specifically in the area where DBI had accumulated. Collectively, this approach shows significant promise for image-guided PDT.

Facile access to site-selective hetero-lanthanide molecules will open new avenues in the search of novel photophysical phenomena based on Ln-to-Ln′ energy transfer (ET). This challenge demands strategies to segregate efficiently different Ln metal ions among different positions in a molecule. We report here the one-step synthesis and structure of a pure [YbNdYb] (1) coordination complex featuring short Yb···Nd distances, ideal to investigate a potential distributive (i.e., from one donor to two acceptors) intramolecular ET from one Nd3+ ion to two Yb3+ centers within a well-characterized molecule. The difference in ionic radius is the mechanism allowing to allocate selectively both types of metal ion within the molecular structure, exploited with the simultaneous use of two β-diketone-type ligands. To assist the photophysical investigation of this heterometallic species, the analogues [YbLaYb] (2) and [LuNdLu] (3) have also been prepared. Sensitization of Yb3+ and Nd3+ in the last two complexes, respectively, was observed, with remarkably long decay times, facilitating the determination of the Nd-to-Yb ET within the [YbNdYb] composite. This ET was demonstrated by comparing the emission of iso-absorbant solutions of 1, 2, and 3 and through lifetime determinations in solution and solid state. The comparatively high efficiency of this process corroborates the facilitating effect of having two acceptors for the nonradiative decay of Nd3+ created within the [YbNdYb] molecule., The authors thank the Spanish AEI for grants PGC2018-098630-B-I00 (G.A. and D.A.), PID2020-118329RB-I00 (O.R.), and the Generalitat de Catalunya for an FI-SDUR Grant (2020-FISDU-00492, D.M.), and the ICREA Academia 2018 Prize (G.A.), as well as the Advanced Light Source, which is a DOE Office of Science User Facility operating under contract no. DE-AC02-05CH11231. This work used resources of the ALBA synchrotron through access to beamline 13-XALOC. This study was also supported by MCIN with funding from European Union NextGenerationEU (PRTR-C17.I1) and by Generalitat de Catalunya.

Aza-boron-dipyrromethenes (Aza-BODIPYs) are an increasingly studied class of fluorophores. They can be seen as an azadipyrromethene ("aza-DIPY") ligand rigidified by a metalloid, a boron atom. Based on this idea, a series of complexes of group 13 metals (aluminum and gallium) have been synthesized and characterized. The impact of the metal and of the nature of the substituents of aza-DIPY core were investigated. The photophysical and electrochemical properties were determined, and an X-ray structure of an azaGaDIPY was obtained. These data reveal that azaGaDIPY and azaAlDIPY exhibit significant red-shifted fluorescence compared to their analogue aza-BODIPY. Their emission can go up to 800 nm for the maximum emission length and up to NIR-II for the emission tail. This, associated with their electrochemical stability (no metal release whether oxidized or reduced) makes them a promising class of fluorophores for optical medical imaging. Moreover, X-ray structure and molecular modeling studies have shown that this redshift seems to be more due to the geometry around the boron/metal than to the nature of the metal.

International audience; New “all-in-one” theranostic systems, combining a magnetic resonance imaging (MRI) contrast agent with a biphotonic photodynamic therapy (2P-PDT) photosensitiser generating cytotoxic singlet oxygen, were envisaged and synthesised. They are based on azamacrocycles, regiospecifically functionalised by two-photon PDT π-conjugated dibromobenzene–picolinate photosensitisers and acetate, able to complex gadolinium(III) and allow an MRI signal. Our approach was to use two different macrocyclic platforms, tacn and pyclen, for modulating simultaneously the structures, properties and solubility of the complexes. Photophysical properties of the ligands and their gadolinium(III) complexes were fully investigated. The Gd3+–pyclen derivative showed the best water solubility and the greatest value of singlet oxygen generation of the series with ΦΔ = 0.53 enabling in vitro studies. The biological PDT activity under mono and biphotonic excitation was evaluated in human breast cancer cells (MCF-7). While a very low dark toxicity was observed, an almost total cell death was induced after only 3 successive irradiations of 1.57 s. Finally, its relaxivity was measured in a DMSO/H2O solvent mixture with r1p = 11.21 and r2p = 24.60 mM−1 s−1 at 3.0 T and T1- and T2-weighted phantom MR images were obtained highlighting a first generation of “all-in-one” PDT/MRI theranostic agents.

Enhanced near-infrared (NIR) luminescence from two structurally related heterobinuclear NaYb eight-cooridnate and heterobinuclear YbNa eight-coordinate (CN = 8) complexes is reported and compared to a nine-coordinate (CN = 9) homoleptic complex. For the heteroleptic complex, [Yb(MPQ)(acac)], the Yb cation is coordinated to two tridentate 2-(5-methylpyridin-2-yl)-8-quinolinate (MPQ) anions, with a bidentate acetylacetonate (acac) anion completing the coordination sphere. Instead, the heterobinuclear [NaYb(MPQ)] complex comprises a total of four anionic MPQ ligands, two of which exhibit κ-coordination to the Yb cation. The remaining two MPQ anions are unidentate toward the lanthanide and form μ-bridges via the deprotonated quinolinate oxygens to a bound Na cation which is also coordinated to the remaining nitrogen donor atoms. The structural properties of these complexes were evaluated by single-crystal X-ray diffraction (SXRD), continuous shape measure (CShM) analysis, and H NMR spectroscopy using a diamagnetic Lu analogue. The corresponding photophysical properties were examined in CHCl solution by using absorption and emission spectroscopy. For both the complexes, characteristic Yb emission is observed at ca. 980 nm, with recorded photoluminescence quantum yields (Φ) and NIR luminescence lifetimes (τ) of 2.0% and 14.0 μs vs 1.5% and 11.6 μs for the [NaYb(MPQ)] and [Yb(MPQ)(acac)] complexes, respectively. Interestingly, the eight-coordinate Yb complexes both have higher photoluminescence quantum yields when compared to the homoleptic [Yb(MPQ)] complex, which has a reported quantum yield of 1.0% and a NIR lifetime determined herein of 13.3 μs under identical conditions. These results have been rationalized by considering the overall efficiency of the ligand-centered sensitization process (η = Φ × Φ), together with subsequent radiative () and nonradiative () deactivation of the Yb cation. Moreover, the efficiency of the intersystem crossing (Φ) and electronic energy transfer (Φ) processes involved in the antennae effect have been quantified for the new complexes using a combination of nanosecond and femtosecond transient absorption techniques and have been compared to our previous results using [Ln(MPQ)] complexes with Ln = Yb and Lu.

Through the preparation and characterization of five new derivatives, the regioselective mono and di, homo and hetero, halogenation of the benzothioxanthene (BTXI) core is demonstrated herein. All structurally solved by X-ray crystallography, these complementary functionalized building blocks open doors to the design of new symmetrical and asymmetrical π-conjugated systems based on this promising but still under-explored rylene.

In this study, an original aza-BODIPY system comprising two Gd3+ complexes has been designed and synthesized for magnetic resonance imaging/optical imaging application, by functionalization of the boron center. This strategy enabled to obtain a positively-charged bimodal probe, which displays an increased water-solubility, optimized photophysical properties in the near-infrared region, and very promising relaxometric properties. The absorption and emission wavelengths are 705 and 741 nm respectively, with a quantum yield of around 10 % in aqueous media. Moreover, the system does not produce singlet oxygen upon excitation, which would be toxic for tissues. The relaxivity obtained is high at intermediate fields (16.1 mM-1.s-1 at 20 MHz and 310 K) and competes with that of bigger or more rigid systems. A full relaxometric and 17O NMR study and fitting of the data using the Lipari-Szabo approach showed that this high relaxivity can be explained by the size of the system and the presence of some small aggregates. These optimized photophysical and relaxometric properties highlight the potential use of such systems for future bimodal imaging studies.

Singlet-triplet interconversions (intersystem crossing, ISC) in organic molecules are at the basis of many important processes in cutting-edge photonic applications (organic light-emitting devices, photodynamic therapy, etc.). Selection rules for these transitions are mainly governed by the spin-orbit coupling (SOC) phenomenon. Although the SOC relies on complex relativistic phenomena, theoreticians have, with time, developed increasingly sophisticated and efficient approaches to gain access to a satisfactory evaluation of its magnitude. However, recent works have highlighted the remarkable and somehow unexpected efficiency of dimers of small conjugated molecules in terms of ISC quantum yields, whose origin has not been completely investigated. In this work, we bring a coupled experimental and theoretical analysis of the origin of the unusually large ISC efficiency on a series of such dimers that differ by their nature (covalent or supramolecular). We show that considering the dynamical nature of the SOC, and especially its dependence on angular orientations between the dimer subunits sometimes overlooked in the literature, it is necessary to rationalize some counterintuitive experimental observations. This combined experimental and theoretical work paves the way for new molecular engineering rules for SOC control.

International audience; Advances in personalized medicine are prompting the development of multimodal agents, that is, molecules that combine properties promoting various diagnostic and therapeutic applications. General approaches exploit chemical conjugation of therapeutic agents with contrast agents or the design of multimodal nanoplatforms. Herein, we report the design of a single molecule that exhibits potential for different diagnostic modes as well as the ability to sensitize oxygen, thus offering potential for photodynamic therapy. Exceptionally, this work involves the synthesis and chiral resolution of an enantiomeric pair of chiral monofluoroborates that contain a stereogenic boron atom. Combining experimental and theoretical chiroptical studies allowed the unambiguous determination of their absolute configuration. Photophysical investigations established the ability of this compound to sensitize oxygen even in the absence of heavy atoms within its structure. The synthesis of a chiral benzothiazole monofluoroborate paves a way to multimodal diagnostic tools (fluorescence and nuclear imaging) while also featuring potential therapeutic applications owing to its ability to activate oxygen to its singlet state for use in photodynamic therapy.

A first series of lanthanide complexes of tris(dipyridyl)pyrrolide ligands has been prepared. The [Ln(dppR1,R2)3] complexes (Ln = La(iii), Sm(iii), Eu(iii), Gd(iii) and Yb(iii); and dppR1,R2 = 2,5-di(2-pyridyl-3-(R1)-4-(R2)) pyrrolide) have been isolated and their structures and photophysical and redox properties characterised, both in the solid-state and in solution. In the complexes, the three dpp- ligands form a distorted tricapped trigonal prismatic coordination geometry about the lanthanide ions, with the antiparallel isomer observed in the solid state for non-symmetric (dppCO2Me,Me)-. However, 1H NMR spectroscopy of the diamagnetic and paramagnetic [Ln(dppR1,R2)3] complexes in d6-benzene solution reveal evidence for a statistical distribution of all possible isomers. Time-resolved luminescence studies suggest that the dpp- ligand (with triplet excited state T1 energy at 18 622 cm-1) sensitises red emission from [Eu(dppCO2Me,Me)3] and near-infrared emission from [Yb(dppCO2Me,Me)3] through the antenna effect. Cyclic voltammetry reveals three consecutive, reversible, one-electron oxidation processes for each [Ln(dppR1,R2)3] complex, corresponding to oxidations of each dpp- ligand between 0.3-0.8 V vs. E1/2 (Fc+/0), and for [Eu(dppCO2Me,Me)3] the EuIII/II couple was -2.099 V vs. E1/2 (Fc+/0).

International audience; The pallado-catalyzed cyanation of benzothioxanthene imide (BTXI) derivatives is explored herein. Once optimized on the monobromo BTXI, mild reaction conditions were successfully applied to the dibromo derivative affording two regioisomers that have been isolated and structurally solved. Additional hydrogen-deuterium exchange experiments were carried out to support a proposed mechanism involving the formation of a five-membered palladacycle intermediate in the bay area. In addition to impact the structural, photo physical and electrochemical properties of the BTXI core, nitrile moieties were successfully used as orthogonal protecting groups thus opening doors to new design principles.

International audience; The electronic structure of a chiral Yb(III)-based complex is fully determined by taking advantage of experimental magnetic, luminescence, and chiroptical (NIR-ECD and CPL) characterizations in combination with ab initio wavefunction calculations. The combined use of these techniques allows determining with high resolution the electronic structure diagram as well as the nature of the different states involved in the magnetic and chiroptical properties of the investigated complex. The crystal-field picture deduced from spectroscopic measurements (absorption and emission) is used to reproduce the magnetic properties. Subsequently, advanced ab initio calculations demonstrate that global chiroptical spectra correspond to the sum of entangled transitions with similar or opposite polarizations.

EuIII, TbIII, GdIII and YbIII complexes of the nonadentate bispidine derivative L2 (bispidine=3,7‐diazabicyclo[3.3.1]nonane) were successfully synthesized and their emission properties studied. The X‐ray crystallography reveals full encapsulation by the nonadentate ligand L2 that enforces to all LnIII cations a common highly symmetrical capped square antiprismatic (CSAPR) coordination geometry (pseudo C4v symmetry). The well‐resolved identical emission spectra in solid state and in solution confirm equal structures in both media. As therefore expected, this results in long‐lived excited states and high emission quantum yields ([EuIIIL2]+, H2O, 298 K, τ=1.51 ms, ϕ=0.35; [TbIIIL2]+, H2O, 298 K, τ=1.95 ms, ϕ=0.68). Together with the very high kinetic and thermodynamic stabilities, these complexes are a possible basis for interesting biological probes., EuIII, TbIII, GdIII and YbIII complexes of a nonadentate bispidine derivative were successfully synthesized and their emission properties studied. The X‐ray crystallography reveals full encapsulation by the nonadentate ligand, and the identical emission spectra in the solid state and in solution confirm equal structures in both media. As therefore expected, this results in long‐lived excited states and high emission quantum yields, making these complexes a possible basis for interesting biological probes.

The ligand HL (6-[3-oxo-3-(2-hydroxyphenyl)propionyl]pyridine-2-carboxylic acid), which exhibits two different coordination pockets, has been exploited to engender and study energy transfer (ET) in two dinuclear [LnLn′] analogues of interest, [EuYb] and [NdYb]. Their structural and physical properties have been compared with newly synthesised analogues featuring no possible ET ([EuLu], [NdLu], and [GdYb]) and with the corresponding homometallic [EuEu] and [NdNd] analogues, which have been previously reported. Photophysical data suggest that ET between Eu and Yb does not occur to a significant extent, whereas emission from Yb originates from sensitisation of the ligand. In contrast, energy migration seems to be occurring between the two Nd centres in [NdNd], as well as in [NdYb], in which Yb luminescence is thus, in part, sensitised by ET from Nd. This study shows the versatility of this molecular platform to further the investigation of lanthanide-to-lanthanide ET phenomena in defined molecular systems., This research was supported by the Spanish MINECO through grants CTQ2015-68370-P and PGC2018-098630-B-I00 (G.A., D.A. and V.V.) and MAT2017-86826-R (O.R.), as well as through the Juan de la Cierva program IJCI-2016-29901 (D.A.) and the Aragón government (DGA, consolidated group PLATON E31_17R). G.A. thanks the Generalitat de Catalunya for the ICREA Academia 2018 prize and QUANTERA for project SUMO (through Spanish grant PCI2018-093106). This research used resources of the Advanced Light Source, which is a DOE Office of Science User Facility under contract no. DE-AC02-05CH11231.

Enhanced near-infrared (NIR) luminescence from two structurally related heterobinuclear Na

In this article, we report on the synthesis and characterization of the tetracarboxylatodirhodium(II) complexes [Rh2(&mu, &ndash, O2CCH2OMe)4(THF)2] (1) and [Rh2(&mu, O2CC6H4&ndash, p&ndash, CMe3)4(OH2)2] (2) by metathesis reaction of [Rh2(&mu, O2CMe)4] with the corresponding ligand acting also as the reaction solvent. The reaction of the corresponding tetracarboxylato precursor, [Rh2(&mu, O2CR)4], with PPh4[Au(CN)2] at room temperature, yielded the one-dimensional polymers (PPh4)n[Rh2(&mu, O2CR)4Au(CN)2]n (R = Me (3), CH2OMe (4), CH2OEt (5)) and the non-polymeric compounds (PPh4)2{Rh2(&mu, O2CR)4[Au(CN)2]2} (R = CMe3 (6), C6H4&ndash, CMe3 (7)). The structural characterization of 1, 3&middot, 2CH2Cl2, 4&middot, 3CH2Cl2, 5, 6, and 7&middot, 2OCMe2 is also provided with a detailed description of their crystal structures and intermolecular interactions. The polymeric compounds 3&middot, 3CH2Cl2, and 5 show wavy chains with Rh&ndash, Au&ndash, Rh and Rh&ndash, N&ndash, C angles in the ranges 177.18&deg, 178.69&deg, and 163.0&deg, 170.4&deg, respectively. A comparative study with related rhodium-silver complexes previously reported indicates no significant influence of the gold or silver atoms in the solid-state arrangement of these kinds of complexes.

Through the preparation and characterization of five new derivatives, the regioselective mono and di, homo and hetero, halogenation of the benzothioxanthene (BTXI) core is demonstrated herein. All structurally solved by X-ray crystallography, these complementary functionalized building blocks open doors to the design of new symmetrical and asymmetrical π-conjugated systems based on this promising but still under-explored rylene.

The selective mono-nitration of benzothioxanthane (BTXI) is demonstrated herein. This leap opens doors to a wide range of chemical reactions since the nitro compound was successfully reduced to a primary amine that was, in turn, converted into an azide. Beyond this chemical achievement, this new series of functionalized BTXI was fully characterized, including from a photophysical point of view, expanding the scope of this promising rylene to build a new electroactive π-conjugated platform for electronic organic purposes.

International audience; The synthesis of benzothioxanthene imide based dimers is reported herein. Subtle chemical modifications were carried out and their impact on the optical and electrochemical properties was investigated for a better structure-property relationship analysis. The icing on the cake was that these new structures were used as light emitting materials for the fabrication and demonstration of the first BTXI-based OLEDs.

© 2019 The Royal Society of Chemistry. Herein we report a nanorod couple heterostructure made of dual semiconductors, in which two parallelly aligned ZnSe nanorods are connected by the growth of ZnS on both end and side facets, producing hetero-ZnS (short arms)-ZnSe (long arms)/ZnS shell nanorod couples. As evidenced by electronic structure studies, both experimental and theoretical, such core/shell nanorod couple heterostructures can act as a platform to precisely tailor the quantum confinement of charge carriers between the constituting components within a single nano-object, generating blue fluorescence after the overgrowth of an alloyed ZnCdS layer on the heterostructures. We foresee the mechanistic insights gained and electronic structures revealed in this work would shed light on the rational design of more complex heterostructures with novel functionalities.

The tetrazole-functionalised calixdiquinone 5,17-di-tert-butyl-26,28-bis-(tetrazol-5-ylmethoxy)- calix[4]-25,27-diquinone Q was synthesised by chemical oxidation of the bis-tetrazole calix[4]arene precursor using PbO2/HClO4. The single crystal X-ray structure determination of Q confirmed the structure and showed binding of a water molecule in the solid state. Chemical reduction of Q to the dihydroquinone QR was achieved using N,N-diethylhydroxylamine. Comparison of the solution phase photophysical properties of Q or QR in the presence of terbium ions showed significant excitation only with QR, suggesting redox switching of the photophysical response may be possible with this or similar receptors.

This research was partially supportedby the Australian Research Council's Discovery Projects funding scheme (project DP17010189), and a Royal Society International Exchanges Grant. EZ-C thanks EPSRC (EP/M02105X/1) for support. L.A.G thanks Curtin University for the postgraduate scholarship. β-Triketonates have been recently used as chelating ligands for lanthanoid ions, presenting unique structures varying from polynuclear assemblies to polymers. In an effort to overcome low solubility of the complexes of tribenzoylmethane, four β-triketones with higher lipophilicity were synthesised. Complexation reactions were performed for each of these molecules using different alkaline bases in alcoholic media. X-ray diffraction studies suggested that the ligands were undergoing decomposition under the reaction conditions. This is proposed to be caused by in situ retro-Claisen condensation reactions, consistent with two examples that have been reported previously. The lability of the lanthanoid cations in the presence of a varying set of potential ligands gave rise to structures where one, two, or three of the molecules involved in the retro-Claisen condensation reaction were linked to the lanthanoid centres. These results, along with measurements of ligand decomposition in the presence of base alone, suggest that using solvents of lower polarity will mimimise the impact of the retro-Claisen condensation in these complexes. Postprint

β-Triketonates have been recently used as chelating ligands for lanthanoid ions presenting unique structures varying from assemblies to polymers. Despite their novel complexation behaviour little is known about the stability of these molecules. Indeed, two examples of possible in situretro-Claisen condensation reactions have been reported previously. To better understand this possible decomposition pathway, four new β-triketones were synthesised. Complexation reactions were performed for each of these molecules using different alkaline bases in alcoholic media, aiming to isolate the potentially varying ligands present in solution. The X-ray diffraction studies revealed the formation of structures where one, two, or three of the molecules involved in the retro-Claisen condensation reaction were linked to the lanthanoid centres.

An isomorphous series of lanthanoid complexes containing tribenzoylmethanide (tbm) and 1,10-phenanthroline (phen) ligands has been synthesised and structurally characterised. These complexes, formulated as [Ln(phen)(tbm)3] (Ln = Eu3+, Er3+ and Yb3+), were compared with analogous dibenzoylmethanide (dbm) [Ln(phen)(dbm)3] complexes to investigate the effect of changing β-diketonate to β-triketonate ligands on the photophysical properties of the complex. The photophysical properties for the Eu3+ complexes were similar for both systems, whereas a modest enhancement was observed for Yb3+ and Er3+ moving from the dbm to the tbm complexes. A detailed study of the NIR photophysical properties was achieved by adapting the integrating sphere method for the calculation of overall quantum yields in the solid state.

Isomorphous β-triketonate-based lanthanoid polymers containing tris(4-methylbenzoyl)methane (mtbm) and RbOH with formula, {[Ln(Rb)(mtbm)4]2}n (Ln = Eu3+ and Nd3+) have been synthesised and structurally characterised. The photophysical properties for the Nd3+ complex presented long lifetimes and relatively high quantum yields in comparison with analogous β-diketonate complexes. Mixed lanthanoid complexes were also formed and their luminescence properties studied, with effective sensitisation of the 4F3/2 of Nd3+ via the 5D0 of Eu3+, which is to the best of our knowledge the first example of Eu3+ to Nd3+ sensitisation in coordination polymers

Isomorphousβ-triketonate-based lanthanoid polymers containing tris(4-methylbenzoyl)methanide (mtbm) and Rb+with formula,{[Ln(Rb)(mtbm)4]2}n (Ln = Eu3+ and Nd3+) have been synthesised and structurally characterised. The photophysical properties for the Nd3+complex presented long lifetimes and relatively high quantum yields in comparison with analogous β-diketonate complexes. Mixed lanthanoid complexes were also formed and their luminescence properties studied, with effective sensitisation of the 4F3/2 of Nd3+ via the 5D0 of Eu3+, which is to the best of our knowledge the first example of Eu3+to Nd3+sensitisation in a coordination complex or polymer.

E.Z.-C. acknowledges the University of St. Andrews and EPSRC (EP/M02105X/1) for financial support. We thank Umicore AG for the gift of materials. We thank the EPSRC UK National Mass Spectrometry Facility at Swansea University for analytical services. This work is supported by a Royal Society International Exchanges Grant and by the Australian Research Council and. LAG thanks Curtin University for the postgraduate scholarship. This work used the computational resources of the CCIPL installed in Nantes. Unconventionally modified dibenzoylmethane (dbm) ligands have been synthesized and successfully utilized as ancillary ligands for neutral Ir(III) complexes of the formula [Ir(dFppy)2(LX)], where dFppyH is 2-(2,4-difluorophenyl)pyridine and LX is tribenzoylmethane ( tbm ) or 1-phenyl-3-(4-(pyridin-2-yl)phenyl)propane-1,3-dione ( pydbm ). The modification of the ligands aims to prevent or enhance possible intermolecular interactions between the dFppy and/or the LX moiety in comparison with the previously reported [Ir(dFppy)2( dbm )] complex. The aggregation induced emission (AIE) properties of these complexes are significantly modulated, as a consequence of the different π-π interactions revealed by X-ray crystallography. Postprint

International audience; The association of the [Ln(hfac)3(H2O)2] metallic building blocks with the new ligand [1,1’-binaphthalene]-8,8’-diylbis(diphenylphosphine oxide) (L) led to the formation of three mononuclear complexes of formula [Ln(hfac)3(L)] (LnIII = Eu (1), Dy (2) and Yb (3)). The mononuclear character of the compounds is due to the bidentate coordination mode adopted by L to link the metal. L allows the observation of the characteristic visible 5D0 -> 7FJ (J = 0-4) EuIII- and near infrared 2F5/2 -> 2F7/2 YbIII- emissions while 2 is only weakly emissive due to the mismatch between the energy positions of the triplet excited state of the ligand and DyIII emissive state. The magnetic data reveal a field-induced Single-Molecule Magnet (SMM) behavior for 2 and 3 with an efficient suppression of the Quantum Tunneling of the Magnetization (QTM). The slow magnetic relaxation occurs through a Raman process while the Orbach contribution is discarded as confirmed by the correlation with the MJ states energy splitting provided by the luminescence spectrum of 3.