Bis-Alkoxide Dysprosium(III) Crown Ether Complexes Exhibit Tunable Air Stability and Record Energy Barrier.

High-performance and air-stable single-molecule magnets (SMMs) can offer great convenience for the fabrication of information storage devices. However, the controversial requisition of high stability and magnetic axiality is hard to balance for lanthanide-based SMMs. Here, a family of dysprosium(III) crown ether complexes possessing hexagonal-bipyramidal (pseudo-D symmetry) local coordination geometry with tunable air stability and effective energy barrier for magnetization reversal (U) are shown.

{ScGd} Heterometallic Rings: Tunable Ring Topology for Spin-Wave Excitations.

Data carriers using spin waves in spintronic and magnonic logic devices offer operation at low power consumption and free of Joule heating yet requiring noncollinear spin structures of small sizes. Heterometallic rings can provide such an opportunity due to the controlled spin-wave transmission within such a confined space. Here, we present a series of {ScGd} ( = 4, 6, 8) heterometallic rings, which are the first Sc-Ln clusters to date, with tunable magnetic interactions for spin-wave excitations.

A C,S bonded quasi-two-coordinate chromium(II) complex showing field-induced slow magnetic relaxation behaviour.

A C,S bonded quasi-two-coordinate Cr(II) complex, Cr(SAr*) (HSAr* = HSCH-2,6(CH-2,4,6-Pr)), has been synthesized according to literature precedent. Magnetic measurements, high-frequency/field electron paramagnetic resonance (HF-EPR) experiments and calculation studies show that the field-induced slow magnetic relaxation behaviour is caused by relatively weak axial magnetic anisotropy.

Targeting C3b/C4b and VEGF with a bispecific fusion protein optimized for neovascular age-related macular degeneration therapy.

Antiangiogenesis therapies targeting vascular endothelial growth factor (VEGF) have revolutionized the treatment of neovascular ocular diseases, including neovascular age-related macular degeneration (nAMD). Compelling evidence has implicated the vital role of complement system dysregulation in AMD pathogenesis, implying it as a potential therapeutic strategy for geographic atrophy in dry AMD and to enhance the efficacy of anti-VEGF monotherapies in nAMD. This study reports the preclinical assessment and phase 1 clinical outcomes of a bispecific fusion protein, efdamrofusp alfa (code: IBI302), which is capable of neutralizing both VEGF isoforms and C3b/C4b.

Ligand Fluorination to Mitigate the Raman Relaxation of Dy Single-Molecule Magnets: A Combined Terahertz, Far-IR and Vibronic Barrier Model Study.

The fast Raman relaxation process via a virtual energy level has become a puzzle for how to chemically engineer single-molecule magnets (SMMs) with better performance. Here, we use the trifluoromethyl group to systematically substitute the methyl groups in the axial position of the parent bis-butoxide pentapyridyl dysprosium(III) SMM. The resulting complexes-[Dy(OL ) py ][BPh ] (L =CH(CF ) 1, CH CF 2, CMe CF 3)-show progressively enhanced T (@100 Oe s ) from 17 K (for 3), 20 K (for 2) to 23 K (for 1).

Tetraanionic arachno-Carboranyl Ligand Imparts Strong Axiality to Terbium(III) Single-Molecule Magnets.

A family of fully sandwiched arachno-lanthanacarborane complexes formulated as {η -[μ-1,2-[o-C H (CH ) ]-1,2-C B H ] Ln}{Li (THF) } (Ln=Tb, Dy, Ho, Er, Y) is successfully synthesized, where the "carbons-adjacent" carboranyl ligand (arachno-R -C B H ) bears four negative charges and coordinates to the central lanthanide ions using the hexagonal η C B face. Thus, the central lanthanide cations are pseudo-twelve-coordinate and have an approximate pseudo-D symmetry or hexagonal-prismatic geometry. As the crystal field effect imparted by this geometry is still unknown, we thoroughly investigated the magnetic properties of this series of complexes and found that the crystal field imposed by this ligand causes a relation of Tb>Dy>Ho>Er for the energy gaps between the ground and the first excited states, which is of striking resemblance to the ferrocenophane and phthalocyanine ligands although the latter two ligands give disparate local coordination geometries.

Studies of the Temperature Dependence of the Structure and Magnetism of a Hexagonal-Bipyramidal Dysprosium(III) Single-Molecule Magnet.

The hexagonal-bipyramidal lanthanide(III) complex [Dy(OBu)Cl(18-C-6)][BPh] (; 18-C-6 = 1,4,7,10,13,16-hexaoxacyclooctadecane ether) displays an energy barrier for magnetization reversal () of ca. 1000 K in a zero direct-current field. Temperature-dependent X-ray diffraction studies of down to 30 K reveal bending of the Cl-Ln-OBu angle at low temperature.

Identification of a novel RPGR mutation associated with X-linked cone-rod dystrophy in a Chinese family.

Background: Cone-rod dystrophy (CORD) is a group of inherited retinal dystrophies, characterized by decreased visual acuity, color vision defects, photophobia, and decreased sensitivity in the central visual field. Our study has identified a novel pathogenic variant associated with X-linked cone-rod dystrophy (XLCORD) in a Chinese family.

Methods: All six family members, including the proband, affected siblings, cousins and female carriers, have underwent thorough ophthalmic examinations.

A study of cation-dependent inverse hydrogen bonds and magnetic exchange-couplings in lanthanacarborane complexes.

Ten lanthanacarborane complexes were synthesized to study the rare B-H∙∙∙M inverse hydrogen bonds (IHBs). The average bonding energy of B-H∙∙∙Ln is theoretically determined to be larger than 24 kJ/mol, which is comparable to moderately strong hydrogen bonds (21-56 kJ/mol). In addition to NMR and IR, magnetometer was used to study the exchange-coupling interaction via such B-H∙∙∙Ln IHBs in detail, and the coupling constant is determined to be -2.

A giant spin molecule with ninety-six parallel unpaired electrons.

Unpaired electrons which are essential for organic radicals and magnetic materials are hardly to align parallel, especially upon the increasing of spin numbers. Here, we show that the antiferromagnetic interaction in the largest Cr(III)-RE (rare earth) cluster {CrRE} leads to 96 parallel electrons, forming a ground spin state of 48 for RE = Gd. This is so far the third largest ground spin state achieved in one molecule.

Magnetic Anisotropy: Structural Correlation of a Series of Chromium(II)-Amidinate Complexes.

Systematic substituent variations on amidinate ligands bring delicate changes of CrN coordination in a family of chromium(II) complexes with the common formula of Cr(RNC(CH)NR), where R = Pr (), Cy (), Dipp (Dipp = 2, 6-diisopropylphenyl) (), and Bu (). With the largest substituent group, shows the largest distortion of the N coordination geometry from square-planar to seesaw shape, which leads to its field-induced single-molecule magnet (SMM) behavior. This is an indication that has the strongest axial magnetic anisotropy and/or optimized magnetic relaxation process.

A Local D Symmetric Dysprosium(III) Single-Molecule Magnet with an Energy Barrier Exceeding 2000 K*.

Three six-coordinate Dy single-molecule magnets (SMMs) [Dy(O Bu) (L) ] with local D symmetry are obtained by optimizing the equatorial ligands. One of the compounds with L=4-phenylpyridine shows an energy barrier (U ) of 2075(11) K, which is the third largest U , and the first U >2000 K for SMMs with axial-type symmetry so far. Ab initio analysis indicates that the exceptional uniaxial magnetic anisotropy is deeply related to the axially compressed octahedral geometry.

Photoreceptors Degenerate Through Pyroptosis After Experimental Retinal Detachment.

Purpose: Gasdermin D (GSDMD) is crucial in neuronal pyroptosis. GSDMD-N and GSDMD-C are two subdomains of the protein GSDMD. GSDMD-N is an executor of pyroptosis, and GSDMD-C has an inhibitory effect on pyroptotic cell death.

xCT regulates redox homeostasis and promotes photoreceptor survival after retinal detachment.

Backgrounds: Photoreceptor degeneration underlies various retinal disorders that lead to vision impairment. Currently, no effective medication is available to rescue photoreceptors under disease conditions. Elucidation of the molecular pathways involved in photoreceptor degeneration is a prerequisite for the rational design of therapeutic interventions.

Terbium-fluorido cluster: an energy cage for photoluminescence.

We report here that energy migration during luminescence can be extremely minimized by caging the fluorescent centers in a molecular cluster of [Tb6(μ3-F)8(piv)10(Hpiv)4DMF]·xDMF·yH2O 1. Experimental and theoretical simulations reveal that bonding terbium with fluoride is the key to reducing the non-radiative multi-phonon relaxation processes, which is disparate to the common hydroxy-based lanthanide clusters.

3-Methyladenine Alleviates Experimental Subretinal Fibrosis by Inhibiting Macrophages and M2 Polarization Through the PI3K/Akt Pathway.

To explore the effects of 3-methyladenine (3-MA), a selective inhibitor of phosphatidylinositol-3-kinase (PI3K), on experimental subretinal fibrosis (SRF) in mice. The SRF mouse model was established by 532 nm laser photocoagulation at each fundus of mice on day 0. 3-MA was administered every 2 days from day 0 to 35.

A stable dysprosium(iii) complex with a terminal fluoride ligand showing high resolution luminescence and slow magnetic relaxation.

An air-stable dysprosium(iii) complex, [C(NH)][DyF(piv)](piv) (piv = pivalate), with a terminal fluoride ligand protected by forming extensive hydrogen bonds with peripheral guanidiniums has been isolated. Though the magnetic data failed to determine the energy barrier for the magnetic reversal (U) accurately, the fine emission spectrum of the F→H transition at 4.2 K and ab initio calculations reveal that the U is about 376(20) K, which is among the highest for high-coordinate (coordination numbers ≥ 9) lanthanide mononuclear magnets.

Dimerized -Semiquinone Radical Anions Stabilized by a Pair of Rare-Earth Metal Ions.

Here we report stable -quinone-radical-bridged rare-earth complexes involving the ligand tetramethylquinone (QMe). The complexes, {Y[(QMe)Cl(THF)]} () and {Gd[(QMe)Cl(THF)]} (), where THF = tetrahydrofuran, are sufficiently stable that we can measure the single-crystal structures and perform magnetic and electron paramagnetic resonance measurements. These studies show the presence of a semiquinone form and that the magnetic interaction between the radicals in the dimer is strong and antiferromagnetic.

Understanding a pentagonal-bipyramidal holmium(iii) complex with a record energy barrier for magnetisation reversal.

We report herein three pentagonal-bipyramidal holmium(iii) complexes sharing the formula [Ho(L)(py)][BPh], where L is the alkoxide ligand. For L = (OSi(CH)), a record energy barrier for magnetization reversal (U = 715(6) K) was revealed, which is due to the pure state transition of m = |±8〉→m = |±7〉→m = |±6〉.

Equatorial coordination optimization for enhanced axiality of mononuclear Dy(iii) single-molecule magnets.

We present a controlled synthetic route to optimize the equatorial coordination environment of three Dy(iii) borohydride complexes: Dy(BH)(THF) (1), [Dy(BH)(THF)][BPh] (2) and [Dy(BH)(18-C-6)][Na(THF)(18-C-6)][BPh] (3) (THF = tetrahydrofuran, BPh = tetraphenyl borate, 18-C-6 = 18-crown-6-ether), which have the same axial coordination environment, while different equatorial sites. Alteration of the coordination environment on the equatorial sites leads to a significant change in their magnetic properties. In the absence of the dc field, complex 1 with three THF molecules and one BH ligand in the equatorial plane shows no single-molecule magnet (SMM) behaviour, complex 2 having five THF molecules at equatorial sites displays small tails of out-of-phase (χ'') signals, and complex 3 containing one 18-C-6 with six O atoms in the equatorial plane exhibits χ'' signals at higher temperatures.

Dysprosiacarboranes as Organometallic Single-Molecule Magnets.

The dicarbollide ion, nido-C B H is isoelectronic with cyclopentadienyl. Herein, we make dysprosiacarboranes, namely [(C B H ) Ln(THF) ][Na(THF) ] (Ln=Dy, 1Dy) and [(THF) (μ-H) Li] [{η -C H (CH ) C B H }Dy{η :η -C H (CH ) C B H } Li] 3Dy and show that dicarbollide ligands impose strong magnetic axiality on the central Dy ion. The effective energy barrier (U ) for the loss of magnetization can be varied by the substitution pattern on the dicarbollide.

A Study of Magnetic Relaxation in Dysprosium(III) Single-Molecule Magnets.

Although the development of single-molecule magnets (SMMs) is rapid, there are only two families of high energy barrier (U ) dysprosium(III) SMMs known so far: the cyclopentadienyl (Cp) family with a sandwich structure and the pentagonal-bipyramidal (PB) family with D symmetry. These high-barrier SMMs, which usually possess U >500 cm allow the separate study of the four magnetic relaxation paths, namely, direct, quantum tunnelling, Raman and Orbach processes, in detail. Whereas the first family is chemically more challenging to modify the Cp rings, it is shown herein that the latter family, with the common formulae [DyX X (L ) ] , such as X /X = OCMe , OSiMe , OPh, Cl or Br ; L =THF/pyridine/4-methylpyridine, can be readily fine-tuned with a range of axial and equatorial ligands by simple substitution reactions.

Chitinase-3-Like-1 Promotes M2 Macrophage Differentiation and Induces Choroidal Neovascularization in Neovascular Age-Related Macular Degeneration.

Purpose: Choroidal neovascularization (CNV) is the principal pathological factor contributing to blindness in neovascular age-related macular degeneration (nAMD). Infiltration of M2 macrophage is thought to contribute to CNV progress, although the way that regulates its differentiation remains unclear. Here, we investigate the role of CHI3L1 in M2 differentiation and angiogenesis in CNV.

Intraocular VEGF deprivation induces degeneration and fibrogenic response in retina.

VEGF is a critical driver of ocular neovascularization under disease conditions. Current therapeutic strategies rely on intraocular delivery of VEGF-antagonizing reagents, which results in sustained suppression of pathogenic vascularization. Although significant advancement has been achieved in VEGF antagonism, substantial adverse effects have been reported in retrospective clinical studies.

Air-Stable Hexagonal Bipyramidal Dysprosium(III) Single-Ion Magnets with Nearly Perfect D Local Symmetry.

Eight-coordinated Dy centres with D symmetry are expected to act as high-performance single-molecule magnets (SMMs) due to the simultaneous fulfilment of magnetic axiality and a high coordination number (a requisite for air stability). But the experimental realization is challenging due to the requirement of six coordinating atoms in the equatorial plane of the hexagonal bipyramid; this is usually too crowded for the central Dy ion. Here a hexaaza macrocyclic Schiff base ligand and finetuned axial alkoxide/phenol-type ligands are used to show that a family of hexagonal bipyramidal Dy complexes can be isolated.