Luminescent Single-Molecule Magnets as Dual Magneto-Optical Molecular Thermometers.

Luminescent thermometry allows the remote detection of the temperature and holds great potential in future technological applications in which conventional systems could not operate. Complementary approaches to measuring the temperature aiming to enhance the thermal sensitivity would however represent a decisive step forward. For the first time, we demonstrate the proof-of-concept that luminescence thermometry could be associated with a complementary temperature readout related to a different property. Namely, we propose to take advantage of the temperature dependence of both magnetic (canonical susceptibility and relaxation time) and luminescence features (emission intensity) found in Single-Molecule Magnets (SMM) to develop original dual magneto-optical molecular thermometers to conciliate high-performance SMM and Boltzmann-type luminescence thermometry. We highlight this integrative approach to concurrent luminescent and magnetic thermometry using an air-stable benchmark SMM [Dy(bbpen)Cl] (H2 bbpen=N,N'-bis(2-hydroxybenzyl)-N,N'-bis(2-methylpyridyl)ethyl-enediamine)) exhibiting Dy3+ luminescence. The synergy between multiparametric magneto-optical readouts and multiple linear regression makes possible a 10-fold improvement in the relative thermal sensitivity of the thermometer over the whole temperature range, compared with the values obtained with the single optical or magnetic devices.

Using N-Heterocyclic Carbenes as Weak Equatorial Ligands to Design Single-Molecule Magnets: Zero-Field Slow Relaxation in Two Octahedral Dysprosium(III) Complexes.

We report the synthesis, structures, and magnetic investigations of two new octahedral dysprosium complexes, based on the original N-heterocyclic carbene (NHC) tridentate bis(phenoxide) ligand, of the respective formulas mer-[DyL(THF)2Cl] (1) and mer-[DyL(THF)3][BPh4] (2), where L = 1,3-bis(3,5-di-tert-butyl-2-oxidophenyl)-5,5-dimethyl-3,4,5,6-tetrahydropyrimidin-1-ium chloride and THF = tetrahydrofuran. The short Dy-O distances in the axial direction in association with the weak donor ability of the NHC moiety provide a suitable environment for slow relaxation of magnetization, overcoming the previous single-molecule magnets based on NHC ligands.

2-Imino-2,3-dihydrobenzoxazole-a useful platform for designing rare- and alkaline earth complexes with variable di- and trianionic O,N,N, ligands.

The reactions of 2-imino-2,3-dihydrobenzoxazole LH with M[N(SiMe3)2]2(THF)2 (M = Yb and Ca) and Y(CH2SiMe3)3(THF)2 proceed with the opening of the dihydrobenzoxazole ring and the elimination of HN(SiMe3)2 or SiMe4. Besides, in the case of Yb[N(SiMe3)2]2(THF)2, an electron transfer from Yb(II) to L takes place and Yb(III) complex 1 is coordinated by a dianionic phenolate ligand containing a pendant radical-anionic diazabutadiene fragment form. When LH is reacted with Ca[N(SiMe3)2]2(THF)2, C-H bond activation of a methyl fragment by imino nitrogen occurs and affords a dimeric calcium complex 2. In 2, the phenolate ligand is dianionic due to the presence of the amido-imino fragment [R-NC(CH3)-C(CH2)-NR']- (R = 2,4-tBu2-C6H2O; R' = 2,6-iPr2C6H3). In situ generated ate-complex {Na(Et2O)n}{Ca[N(SiMe3)2]3} also enables C-H bond activation, however the dianionic phenolate ligand in the resulting complex 3 contains an amido-imino fragment [R-N-C(CH2)-C(CH3)NR']- featuring the sequence of N-C and NC bonds opposite to that in 2. The reaction of Y(CH2SiMe3)3(THF)2 with LH affords mono(alkyl) yttrium complex 4. 4 contains a dianionic amido-imino phenolate ligand resulting from the migration of one alkyl group to the CN bond [R-N-C(Me)(CH2SiMe3)-C(Me)NR']. 4 undergoes slow intramolecular C-H bond activation of the residual CH3 group to afford a yttrium complex coordinated by a trianionic diamido-phenolate ligand [R-N-C(Me)(CH2SiMe3)-C(CH2)NR'].

A rational study of the influence of Mn2+-insertion in Prussian blue nanoparticles on their photothermal properties.

We investigated a series of Mn2+-Prussian blue (PB) nanoparticles NazMnxFe1-x[Fe(CN)6]1-y□y·nH2O of similar size, surface state and cubic morphology with various amounts of Mn2+ synthesized through a one step self-assembly reaction. We demonstrated by a combined experimental-theoretical approach that during the synthesis, Mn2+ substituted Fe3+ up to a Mn/Na-Mn-Fe ratio of 32 at% in the PB structure, while for higher amounts, the Mn2[Fe(CN)6] analogue is obtained. For comparison, the post-synthetic insertion of Mn2+ in PB nanoparticles was also investigated and completed with Monte-Carlo simulations to probe the plausible adsorption sites. The photothermal conversion efficiency (η) of selected samples was determined and showed a clear dependence on the Mn2+amount with a maximum efficiency for a Mn/Na-Mn-Fe ratio of 10 at% associated with a dependence on the nanoparticle concentration. Evaluation of the in vitro photothermal properties of these nanoparticles performed on triple negative human breast adenocarcinoma (MDA-MB-231) cells by using continuous and pulsed laser irradiation confirm their excellent PTT efficiency permitting low dose use.

High magnetization reversal barriers in luminescent dysprosium octahedral and pentagonal bipyramidal single-molecule magnets based on fluorinated alkoxide ligands.

We report the synthesis and structures of three luminescent dysprosium(iii) complexes based on fluorinated alkoxide ligands of formulas [Dy(L1)2(THF)4][BPh4]·0.5THF (1), [Dy(L2)2(THF)5][BPh4]·2.5THF (2) and [Dy(L3)2(THF)5][BPh4]·2THF (3) (L1 = (CF3)3CO-, L2 = C6F5C6F4O-, L3 = C6F5C(CH3)O-). Despite the different dysprosium ion geometries (octahedral vs. distorted pentagonal bipyramidal), these systems exhibit a single-molecule magnet (SMM) behavior, but with distinct relaxation dynamics. Moreover, a typical dysprosium-based luminescence is observed for the three complexes, which make them bifunctional magneto-luminescent SMMs. Remarkably, complex 3 exhibits a high anisotropy barrier of 1469 cm-1 and a blocking temperature of 22 K, making it one of the most performant alkoxide-based SMMs with the highest blocking temperature for a luminescent SMM.

Temperature sensing in Tb3+/Eu3+-based tetranuclear silsesquioxane cages with tunable emission.

New luminescent cage-like tetranuclear silsesquioxanes [NEt4][(Ph4Si4O8)2(Tb3Eu)(NO3)4(OH)(EtOH)3(H2O)]·4(EtOH) (1) and [NEt4]2[(Ph4Si4O8)2(Tb2Eu2)(NO3)6(EtOH)2(MeCN)2]·4(MeCN) (2) present a tunable thermosensitive Tb3+-to-Eu3+ energy transfer driven by Tb3+ and Eu3+ emission and may be used as temperature sensors operating in the range 41-100 °C with excellent linearity (R 2 = 0.9990) and repeatability (>95%). The thermometer performance was evidenced by the maximum relative sensitivity of 0.63% °C-1 achieved at 68 °C.

New Luminescent Tetranuclear Lanthanide-Based Silsesquioxane Cage-Like Architectures.

Invited for the cover of this issue are Alexey N. Bilyachenko, Joulia Larionova and co-workers at the Russian Academy of Sciences, the Peoples' Friendship University of Russia, and University of Montpellier. The image depicts lanthanide-based cage-like silsesquioxanes exhibiting magnetic and luminescence properties that could constitute a particularly interesting new family related to multifunctional nanomaterials. Read the full text of the article at 10.1002/chem.202003351.

Single-molecule magnet behavior in heterolopetic Dy3+-chloro-diazabutadiene complexes: influence of the nuclearity and ligand redox state.

We report the synthesis, structure and magnetic properties investigations of a series of new dysprosium heteroleptic mono- and dinuclear complexes based on the association of chloride and different diazabutadiene (DAD2R = [2,6-iPr2C6H3N-CR[double bond, length as m-dash]CR-NC6H3iPr2-2,6]; R = H, Me) ligands showing different redox states. While using dianionic DAD2R ligands affords the formation of dichloro-bridged dinuclear complexes [Dy2(DAD2R)(µ-Cl)2(THF)2] (R = H (1), Me (2)), two different mononuclear complexes of general formula [DyCl2(DAD2R)(THF)2] (R = H (3), Me (4)) could be obtained with either a radical monoanionic and a monoanionic DAD2R state, respectively. Remarkably, all the complexes exhibit a slow relaxation of their magnetization where the relaxation dynamics depends on both the nuclearity of the system and the DAD2R redox state.

New Luminescent Tetranuclear Lanthanide-Based Silsesquioxane Cage-Like Architectures.

The synthesis, structure, magnetic, and luminescence properties investigations of four new cage-like lanthanide-based silsesquioxanes (Cat)2 [(PhSiO1.5 )8 (LnO1.5 )4 (O)(NO2.5 )6 (EtOH)2 (MeCN)2 ] (where Cat+ =Et4 N+ , PPh4 P+ and Ln3+ =Eu3+ , Tb3+ and (Ph4 P)4 [(PhSiO1.5 )8 (TbO1.5 )4 (O)2 (NO2.5 )8 ]⋅10MeCN are reported. They present an unusual prism-like topology of cage architectures and lanthanide-characteristic emission, which makes them the first luminescent cage-like lanthanide silsesquioxanes. One of the Tb3+ -based cages presents a magnetic spin-flip transition.

Synthesis, Structure, Magnetic and Photoluminescent Properties of Dysprosium(III) Schiff Base Single-Molecule Magnets: Investigation of the Relaxation of the Magnetization.

We report here the synthesis, structure, magnetic and photoluminescent properties of three new bifunctional Schiff-base complexes [Dy(L1 )2 (py)2 ][B(Ph)4 ]⋅py (1), [Dy(L1 )2 Cl(DME)] ⋅ 0.5DME (2) and [Dy(L2 )2 Cl] ⋅ 2.5(C7 H8 ) (3) (HL1 =Phenol, 2,4-bis(1,1-dimethylethyl)-6-[[(2-methoxy-5-methylphenyl)imino]methyl]; HL2 =Phenol, 2,4-bis(1,1-dimethylethyl)-6-[[(2-methoxyphenyl)imino]methyl]). The coordination environment of the Dy3+ ion and the direction of the anisotropic axis may be controlled by the combination of the substituent groups of the Schiff bases, the nature of the counter-ions (Cl- vs. BPh4 - ) and the coordinative solvent molecules. A zero-field slow relaxation of the magnetization is evidenced for all complexes but strong differences in the relaxation dynamics are observed depending on the Dy3+ site geometry. In this sense, complex 1 exhibits an anisotropy barrier of 472 cm-1 , which may be favourably compared to other related examples due to the shortening of the Dy-O bond in the axial direction. Besides, the three complexes exhibit a ligand-based luminescence making them as bifunctional magneto-luminescent systems.

Single-molecule magnet behavior in luminescent carbazolyl Dy(iii) octahedral complexes with a quasi linear N--Dy-N- angle.

We report the synthesis, photoluminescence and magnetic properties of two octahedral dysprosium complexes [DyR2(py)4][BPh4]·2py (1) and [DyR2(THF)4][BPh4] (2) (R = carbazolyl, py = pyridine, THF = tetrahydrofuran) exhibiting a quasi linear N-Dy-N angle in the axial direction, suitable for providing a coordination environment allowing the zero-field slow relaxation of magnetization.

Fashioning Prussian Blue Nanoparticles by Adsorption of Luminophores: Synthesis, Properties, and in Vitro Imaging.

We report the postsynthetic functionalization of Prussian blue (PB) nanoparticles by two different luminophores (2-aminoanthracene and rhodamine B). We show that the photoluminescence properties of the fluorophores are modified by a confinement effect upon adsorption and demonstrate that such multifunctional nanosized systems could be used for in vitro imaging.

Room temperature magnetoelectric coupling in a molecular ferroelectric ytterbium(III) complex.

Magnetoelectric (ME) materials combine magnetic and electric polarizabilities in the same phase, offering a basis for developing high-density data storage and spintronic or low-consumption devices owing to the possibility of triggering one property with the other. Such applications require strong interaction between the constitutive properties, a criterion that is rarely met in classical inorganic ME materials at room temperature. We provide evidence of a strong ME coupling in a paramagnetic ferroelectric lanthanide coordination complex with magnetostrictive phenomenon. The properties of this molecular material suggest that it may be competitive with inorganic magnetoelectrics.

Synergic effect of doxorubicin release and two-photon irradiation of Mn2+-doped Prussian blue nanoparticles on cancer therapy.

We demonstrate here that Mn2+-doped Prussian blue nanoparticles of ca. 55 nm loaded with doxorubicin may be used as efficient therapeutic agents for combined photothermal and chemo-therapy of cancer cells with a synergic effect under two photon irradiation.

Ancillary Findings on CT Pulmonary Angiograms that are Negative for Pulmonary Embolism.

CONTEXT: One advantage of computed tomographic pulmonary angiograms (CTPA) is that they often show pathology in patients in whom pulmonary embolism (PE) has been excluded. In this investigation, we identified the ancillary findings on CTPAs that were negative for PE to obtain an impression of the type of findings shown. METHODS: This was a retrospective analysis of findings on CTPAs that were negative for PE obtained in nine emergency departments between January 2016 - February 2018. Ancillary findings were assessed by review of the radiographic reports. RESULTS: Ancillary findings were identified in N=338 (40.9%) of 825 patients with CTPAs that were negative for PE. Most ancillary findings, 254 (75.1%) of 338 were pulmonary or pleural abnormalities. Liver, gall bladder, kidney, or pancreatic abnormalities were shown in 26 (7.7%) cases, and abnormalities of the heart or great vessels were shown in 23 (6.8%) of cases. Abnormalities of the esophagus or intestine were shown in 12 (3.6%), abnormalities of the thyroid in 10 (3.0%) and abnormalities of bone or soft tissue lesions were shown in three (0.9%) cases. Inferential statistical procedures demonstrated that the occurrence of ancillary findings in patients with negative CTPAs was proportionately greater in patients who were 50 years and older (p < 0.001), although not between genders (p = 0.145). CONCLUSIONS: Ancillary findings on CTPAs that were negative for PE were frequently reported. Future studies might focus of the extent to which ancillary findings on CTPA assisted physicians in management of the patient.

Crossover from Antiferromagnetic to Ferromagnetic Exchange Coupling in a New Family of Bis-(µ-phenoxido)dicopper(II) Complexes: A Comprehensive Magneto-Structural Correlation by Experimental and Theoretical Study.

Five neutral bis(µ-phenoxido)dicopper(II) complexes, [Cu2(LMe,Me,Me)2] (1), [Cu2(LMe,Me,Et)2]·CH2Cl2 (2), [Cu2(L i-Pr,i-Pr,i-Pr)2]·2H2O (3), [Cu2(L t-Bu,Me,i-Pr)2] (4), and [Cu2(L t-Bu,t-Bu,i-Pr)2]·H2O (5) have been synthesized and characterized by single-crystal X-ray diffraction analyses, magnetic studies, and density functional theory (DFT) calculations, in which the ligands [H2LMe,Me,Me = N,N-bis(2-hydroxy-3,5-dimethylbenzyl)-N',N'-dimethylethylene-1,2-diamine, H2LMe,Me,Et = N,N-bis(2-hydroxy-3,5-dimethylbenzyl)-N',N'-dimethylethylene-1,2-diamine, H2L i-Pr,i-Pr,i-Pr = N,N-bis(2-hydroxy-3,5-diisopropylbenzyl)-N',N'-diisopropylethylene-1,2-diamine, H2L t-Bu,Me,i-Pr = N,N-bis(2-hydroxy-3-tert-butyl-5-methylbenzyl)-N',N'-diisopropylethylene-1,2-diamine, and H2L t-Bu,t-Bu,i-Pr = N,N-bis(2-hydroxy-3,5-di-tert-butylbenzyl)-N',N'-diisopropylethylene-1,2-diamine] contain the same [O,N,N,O]-donor atoms combination but differ in substituents at phenol rings and at an amino nitrogen atom. The effect of these remote substituents on the nature of exchange coupling interactions (ferromagnetic vs antiferromagnetic) between the copper(II) ions has been investigated. The average Cu-O-Cu angle, Cu-O-Cu-O torsion angle, and Cu···Cu separation in 1-5 are varied systematically by these remote ligand substituents in the range 98.6-83.3°, 26.0-46.5°, and 2.982-2.633 Å, respectively. As a result, the intramolecular spin-spin coupling in these complexes are changing gradually from a strong antiferromagnetic (J = -395 cm-1, where H = -JS 1 S 2) to a moderate ferromagnetic (J = +53.2 cm-1) regime. The crossover angle at which the magnetic interaction changes from antiferromagnetic to ferromagnetic (J = 0) is determined to be ca. 87° for this series of dicopper(II) complexes. DFT calculations support the experimentally determined crossover angle and disclose various magneto-structural correlations in the series 1-5.

Synthesis, structure and magnetic properties of a series of Ln(iii) complexes with radical-anionic iminopyridine ligands: effect of lanthanide ions on the slow relaxation of the magnetization.

We report the investigation of synthesis, structure and magnetic properties of a series of homoleptic Ln(iii) complexes coordinated by radical-anionic iminopyridine ligands of general formula [Ln(IPy)3]·solv (IPy = iminopyridine; Ln = Tb, Dy, Er, Y, Gd). The dysprosium analogue exhibits a zero-field Single-Molecule Magnet (SMM) behavior.

Synthesis, structure and magnetic properties of a series of dinuclear heteroleptic Zn2+/Ln3+ Schiff base complexes: effect of lanthanide ions on the slow relaxation of magnetization.

We report an investigation on the synthesis, structure and magnetic properties of a series of heteroleptic Zn2+/Ln3+ complexes of the general formula [ZnLClLn(o-van)(H2O)(NO3)]·H2O (H2L = N,N'-bis(3-methoxysalicylidene)-1,2-diaminoethane; o-van = o-vanillinate; Ln = Tb (1), Dy (2), Er (3)). All the compounds exhibit a slow relaxation of their magnetization and the dysprosium analogue shows one of the highest anisotropic barriers for ZnDy complexes.

Actionable molecular alterations in advanced gynaecologic malignancies: updated results from the ProfiLER programme.

OBJECTIVES: The objectives of this study were to identify actionable genomic alterations in the gynaecological subpopulation of the ProfiLER programme and to report clinical efficacy of recommended targeted treatment (RTT). METHODS: The ProfiLER programme (NCT01774409) is a multicentric prospective trial aiming to implement molecular profiling in patients with advanced refractory cancers. In this programme, tumour DNA is analysed by targeted next-generation sequencing (69 genes) and by whole genome array comparative genomic hybridisation. Clinical cases and genomic profiles are presented in a dedicated molecular tumour board to guide treatment strategies. We report here an analysis of patients with gynaecological cancers included in this trial. RESULTS: From February 2013 to February 2017, 309 patients with gynaecologic cancer were included; 279 (90%) had sufficient quality, and 131 patients (42.4%) had at least one actionable genomic alteration in cancer cells. Four alterations were shared by at least 3% of the patients: 27 (9.7%) PIK3CA mutations, 15 (5.4%) KRAS mutations, 11 (3.9%) ERBB2 amplifications and 9 (3.2%) CDKN2A deletions. Forty-one treatments were initiated among 39 patients (12.6% of the screened population): 8 (20%) had a partial response, and other 10 (24%) had a stable disease. The median progression-free survival was 2.7 months. The median overall survival was 15.6 months for patients who received a RTT. CONCLUSION: Molecular profiling identified actionable alterations in 42.4% of patients with advanced refractory gynaecologic cancer, but only 12.6% were treated with a RTT. Among them, 46% derived clinical benefit (5.8% of the screened population).

Gold@Prussian blue analogue core-shell nanoheterostructures: their optical and magnetic properties.

Au@Prussian-Blue Analogue (PBA) shell nanoheterostructures are multifunctional nano-objects combining optical properties (surface plasmon resonance) of the Au core and magnetic properties of the PBA shell. We report in this article a series of new Au core@PBA shell nano-objects with different PBA shells: Au@K/Co/[FeII(CN)6] (2) and Au@K/Ni/[CrIII(CN)6]:[FeII(CN)6] (3) single PBA shell, as well as Au@K/Ni/[FeII(CN)6]@K/Ni/[FeIII(CN)6] (4) double PBA shell and Au@K/Ni/[FeII(CN)6]@K/Ni/[FeIII(CN)6]@K/Ni/[CrIII(CN)6] (5) triple PBA shell systems. The position and intensity of the Au SPR band, as well as the magnetic behaviour of the nanoheterostructures, are strongly affected by the shell composition and its thickness.