Toroidal moment and dynamical control in luminescent 1D and 3D terbium calixarene compounds.

A toroidal moment can be generated spontaneously in inorganic (atom-based) ferrotoroidic materials that breaks both time-reversal and space-inversion symmetries, attracting great attention in solid-state chemistry and physics. In the field of molecular magnetism, it can also be achieved in lanthanide (Ln) involved metal-organic complexes usually with a wheel-shaped topological structure. Such complexes are called single-molecule toroics (SMTs), presenting unique advantages in spin chirality qubits and magnetoelectric coupling. However, to date, the synthetic strategies of SMTs have remained elusive, and the covalently bonded three-dimensional (3D) extended SMT has not hitherto been synthesized. Here, two luminescent Tb(iii)-calixarene aggregates with architectures of 1D chain (1) and 3D network (2) both containing the square Tb4 unit have been prepared. Their SMT characteristics deriving from the toroidal arrangement of the local magnetic anisotropy axes of Tb(iii) ions in the Tb4 unit have been investigated experimentally with the support of ab initio calculations. To the best of our knowledge, 2 is the first covalently bonded 3D SMT polymer. Remarkably, solvato-switching of SMT behavior has also been achieved for the first time by desolvation and solvation processes of 1.

Eu-Mn Charge Transfer and the Strong Charge-Spin-Electronic Coupling Behavior in EuMnO3.

Based on first-principles calculations with the DFT + U method, the couplings of lattice, charge, spin, and electronic behaviors underlying the Eu-Mn charge transfer in a strongly correlated system of EuMnO3 were investigated. The potential valence transition from Eu3+/Mn3+ to Eu2+/Mn4+ was observed in a compressed lattice with little distortions, which is achieved under hydrostatic pressure and external strain. The intraplane antiferromagnetism (AFM) of Mn is proved to be instrumental in the emergence of Eu2+. Furthermore, we calculated the magnetic exchange interactions within two equilibrium structures of Eu3+Mn3+O3 and Eu2+Mn4+O3. Mn-Mn ferromagnetic exchange in the ab-plane is enhanced strongly in the Eu2+Mn4+O3 structure, contributing to the existence of mixed states. The versatile electronic structures were obtained within the Eu2+Mn4+O3 phase by imposing different magnetic configurations on the Eu and Mn sublattice, attributed to the coupling of charge transfer and magnetic orderings. It is found that the intraplane ferromagnetic ordering of Mn leads to a metallic electronic structure with the coexistence of Eu2+ and Eu3+, while the intraplane AFM Mn spin ordering leads to insulating states only with Eu2+. Notably, a half-metallic characteristic emerges at the magnetic ground state of CF ordering (C-type AFM for the Eu sublattice and ferromagnetic for the Mn sublattice), which makes such a supposed phase more intriguing than the conventional experimental phase. Additionally, the mixture of delocalized 4f with 5d states of Eu in the background of Mn 3d and O 2p orbitals implies a pathway of Eu 4f 5d ↔ O 2p ↔ Mn 3d for charge transfer between Eu and Mn. Our calculation shows that the Eu-Mn charge transfer could be expected in compressed EuMnO3 and the introduction of Eu2+ 4f states near the Fermi level plays an important role in manipulating the interlinks of charge and spin together with electronic behaviors.

Hypothyroid myopathy with periodic paralysis as the main symptom: a case report and literature review.

Hypothyroid myopathy is a skeletal muscle disease caused by hypothyroidism. However, patients with hypothyroidism are often misdiagnosed as polymyositis if they do not have a clear history of thyroid gland or obvious hypometabolic symptoms, but with myasthenia and myalgia as the main symptoms or the first symptoms. Moreover, hypothyroid myopathy with periodic paralysis as the first symptom is rare in clinic. In this study, we summarized the clinical data of 1 case of hypothyroid myopathy with periodic paralysis as the first symptom in our clinical diagnosis and treatment. A 27-year-old male patient with recurrent periodic paralysis was found with hypothyroidism during a most recent attack of myasthenia and was diagnosed with hypothyroid myopathy, which was relieved after oral administration of levothyroxine. We also found 13 similar cases reported internationally, and summarized their clinical characteristics, diagnosis, and treatment methods to provide reference for the clinical diagnosis and treatment of such cases. In general, periodic paralysis may be the main symptom or even the first symptom of hypothyroid myopathy, which is easy to be confused with renal tubular acidosis (RTA) or other autoimmune diseases. The diagnosis is mainly based on the detection of thyroid function and thyroid autoantibodies. Timely supplement of thyroxine and correction of electrolyte disorders are the key to treatment.

Calixarene-Based {Ni18} Coordination Wheel: Highly Efficient Electrocatalyst for the Glucose Oxidation and Template for the Homogenous Cluster Fabrication.

Catalyst plays a very important role in the exploration of new energy. To obtain a highly efficient electrocatalyst for the glucose oxidation and tiny metal nanocluster catalysts, a calixarene-based {Ni18} coordination wheel with sulfur atoms on the cavity surface was designed, synthesized, and used as the porous template. Contributing from the active sites of nickel cations, the as-synthesized coordination wheels can efficiently catalyze the electrochemical oxidation of glucose with the onset and peak potentials of 0.3 and 0.46 V in alkaline medium, and the catalysis does not depend on the atmosphere (N2, air, or O2), which indicates that the coordination wheel will be a promising electrocatalyst candidate for the compartmentless glucose-air fuel cell. Meanwhile, benefiting from its confined cavity and inner sulfur surface, such a coordination wheel can serve as a general template for the fabrication and encapsulation of tiny metal nanoclusters of Au, Pd, Ir, Ru, Rh, Pt, and AuPd. In electrochemical examinations, the bimetallic AuPd clusters confined in the coordination wheel show higher current density than commercial Pt/C toward hydrogen evolution reaction (HER). The present study shows that the designed coordination wheel can be used as not only a type of novel catalyst itself but also a class of templates for metal cluster catalysts.

A metal-calixarene coordination nanotube with 5-(pyrimidin-5-yl)isophthalic acid.

A metal-organic nanotube (MONT) was assembled by bridging the truncated metal-calixarene octahedra with coordinating water molecules. Remarkably, the tubular compound exhibited a much higher sorption capacity for C2H6 and C3H8 than for CH4, and hence represents a promising material for separating these gases. The addition of a little NiSO4 into the reaction system led to the formation of a 2D metal-calixarene network.

Organoamine-induced isomerism of calixarene-based complexes: from 1D to 2D.

Two isomers of the calixarene-based cobalt complex [Co4Cl(TC4A)(BCPT)2]- (H4TC4A = p-tert-butylthiacalix[4]arene; H2BCPT = 3,5-bis (4'-carboxy-phenyl)-1,2,4-triazole) were obtained under the solvothermal conditions with tetramethylammonium/tetraethylammonium hydroxide (CIAC-236) and triethylamine (CIAC-237). Single crystal X-ray diffraction reveals that CIAC-236 has a 1D zigzag aggregate constructed by bridging the shuttlecock-like Co4-TC4A secondary building units (SBUs) with two pairs of opposite V-shaped BCPT ligands while CIAC-237 possesses a 2D layer assembly with each Co4-TC4A SBU bonded by four BCPT ligands in a same direction (clockwise or counterclockwise), which indicates that different shapes of the organoamines lead to different assembly of the BCPT ligands and the formation of different extended aggregates. For comparison, only the 1D structure ([Fe4Cl(TC4A)](BCPT)2]-, CIAC-238) was obtained for the iron complexes with all these three organoamines, which would be attributed to different property and coordination of iron element. Magnetic properties of all these three compounds were studied.

Ultrafine Pt Nanoclusters Confined in a Calixarene-Based {Ni24} Coordination Cage for High-Efficient Hydrogen Evolution Reaction.

To obtain stable and ultrafine Pt nanoclusters, a trigonal prismatic coordination cage with the sulfur atoms on the edges was solvothermally synthesized to confine them. In the structure of {Ni24(TC4A-SO2)6(TDC)12 (H2O)6} (H4TC4A-SO2 = p-tert-butylsulfonylcalix[4]arene; H2TDC = 2,5-thiophenedicarboxylic acid), three Ni4-(TC4A-SO2) SBUs are bridged by three TDC ligands into a triangle and two such triangles are pillared by three pairs of TDC ligands to form a trigonal prism. The cage cavity has 12 sulfur atoms on the surface. Because of the porous structure and strong covalent interaction between metal and sulfur, ultrafine Pt nanoclusters composed of less than ∼18 Pt atoms can be facilely confined in the present trigonal prismatic cage (Pt@CIAC-121). The as-synthesized Pt NCs exhibit higher electrocatalytic activity than commercial Pt/C toward hydrogen evolution reaction.

Discrete {Ni40} Coordination Cage: A Calixarene-Based Johnson-Type (J17) Hexadecahedron.

We report a Johnson hexadecahedronal coordination cage, constructed via 10 Ni4-p-tert-butylthiacalix[4]arene (Ni4-TC4A) units as vertices and 16 5-(pyridin-4-yl)isophthalate (PIP) ligands as tiles. It features a gyroelongated square bipyramidal geometry, equivalent to two square pyramids pillared by a square antiprism, a J17 Johnson solid. Remarkably, the cage compound exhibits a much higher uptake capacity of C3H8 than CH4, representing a promising material for separation of these two gases. In contrast, Co4-TC4A units are linked by PIP ligands and rare {Co4O4Cl2} clusters, providing a one-dimensional bamboo stick-like polymer.

Structure modeling, synthesis and X-ray diffraction determination of an extra-large calixarene-based coordination cage and its application in drug delivery.

An extra-large octahedral coordination cage (CIAC-114) was designed and modeled based on Co4-p-tert-butylsulfonylcalix[4]arene (Co4-(SC4A-SO2)) subunits and 4,4',4''-(benzene-1,3,5-triyl-tris(benzene-4,1-diyl))tribenzoate (BBB) ligands via the isomorphic replacement approach built from an analogous cage structure with a smaller size. X-ray crystallography revealed that the crystals obtained through solvothermal synthesis exhibited the anticipated structure. Each CIAC-114 cage is assembled by six tetranuclear Co4-(SC4A-SO2) units as vertices, which bear a four-fold rotational symmetry, and eight tripodal BBB ligands as linkers, which hold a D3h symmetry. Among its analogues CIAC-114 has the largest overall peripheral diameter of 5.4 nm and an internal cavity of 2.7 nm. After treatment by supercritical CO2, a single crystal sample of CIAC-114 transformed into amorphous material with the retention of the cage skeleton, which demonstrated good adsorption properties towards a small drug molecule, ibuprofen (Ibu), evidenced by IR spectroscopy, (1)H NMR spectroscopy, N2 sorption analysis, and drug release experiments. The Ibu release experiment in phosphate buffered saline solution (pH = 7.4) revealed that CIAC-114 exhibited a slow drug release behavior.

Two elongated octahedral coordination cages constructed by M4-TC4A secondary building units (M = CoII and FeII) and 2,2'-bipyridine-4,4'-dicarboxylic acids.

Two nanoscale coordination cages based on M4-TC4A (M = Co(II) and Fe(II); H4TC4A = p-tert-butylthiacalix[4]arene) and 2,2'-bipyridine-4,4'-dicarboxylic acid (H2bpdc) have been synthesized and characterized. In these isostructural structures, there are two kinds of shuttlecock-like M4-TC4A secondary building units, {M4(TC4A)(Cl)} and {M4(TC4A)(SO4)}, which have different coordination environments and are bridged by bpdc molecules into an elongated octahedron through a [6 + 8] condensation. The gas sorption and magnetic properties were studied.

Two 2D metal-calixarene aggregates incorporating pre-designed coordination nanocages.

Two 2D metal-calixarene aggregates were designed and assembled by M4-TC4A (M = Fe, Co; TC4A = p-tert-butylthiacalix[4]arene) SBUs and {MCl2} units with isonicotinic acid molecules, which presents a possible way to build the extended metal-calixarene assemblies incorporating pre-designed nanocages using multifunctional linkers.

A tetragonal prismatic {Co32} nanocage based on thiacalixarene.

A novel coordination nanocage was obtained with in situ-generated tetrazole ligands from the cobalt-thiacalix[4]arene system. Four in situ-generated 1,3-bis(2H-tetrazol-5-yl)benzene ligands bolster eight Co4-calix shuttle-cock-like secondary building units (SBUs) into a hollow tetragonal prism with a high surface area. The unprecedented {Co32} nanocage presents the highest nuclearity example.

A giant coordination cage based on sulfonylcalix[4]arenes.

A strategy for building coordination cages by a [6 + 8] condensation of M(II)(4)-calix SBUs and rigid ancillary ligands was successfully applied to a cobalt-sulfonylcalix[4]arene system. A giant cage obtained with BTE ligands has an overall periphery diameter of 5.0 nm and an internal spherical cavity of 2.3 nm.

p-tert-Butylthiacalix[4]arene-supported high-nuclearity {Co24M8} (M=Mo or W) nanospheres and the hybrids with Keggin polyoxometalates.

Two hybrid assemblies (3 and 4) with two kind of nanoscaled cluster units, the spherical [Co(24)(TC4A)(6)(MO(4))(8)Cl(6)](2+) cation (1 and 2) and Keggin-type [PM(12)O(40)](3-) anion (M = Mo (1/3), W (2/4)), were solvothermally prepared and characterized, in which the spherical units are constructed by six Co(4)-p-tert-butylthiacalix[4]arene (Co(4)-TC4A) SBUs linked by eight MO(4) tetrahedrons and present the highest nuclearity bimetallic clusters capped by cailxarenes.

Mn4-hinged bithiacalix[4]arenes accommodating fullerenes.

The calixarene-Mn(4)-calixarene dumbbell-like unit can accommodate different fullerenes with its changeable curved surfaces and the addition of fullerenes completely remodels the packing of the dumbbell units.

Making a [Co24] metallamacrocycle from the shuttlecock-like tetranuclear cobalt-calixarene building blocks.

A [Co(24)] metallamacrocycle with a [36-MC(Co)-12] periphery and an inner [24-MC(Co)-6] rim is constructed by linking six Co(4)-thiacalixarene shuttlecock-like SBUs with twelve 1,2,4-triazole molecules.

Three p-tert-butylthiacalix[4]arene-supported cobalt compounds obtained in one pot involving in situ formation of N6H2 ligand.

Three p-tert-butylthiacalix[4]arene (H(4)TC4A)-supported Co(II) compounds, [Co(4)(TC4A)(N(3))(4)(N(6)H(2))(CH(3)OH)](CH(3)OH)(2) (1), [Co(8)(TC4A)(2)(N(3))(2)(N(6)H(2))(2)(CH(3)COO)(4)(CH(3)OH)(4)](OH)(2)(CH(3)OH)(4) (2), and [Co(10)(TC4A)(4)(N(3))(4)](CH(3)OH)(4) (3), have been solvothermally obtained in one pot and structurally characterized by single-crystal X-ray diffraction analyses, powder XRD, and IR spectroscopy. This work presents the first one-dimensional (1) cobalt cluster for the calixarene complexes and another two octanuclear (2) or decanuclear (3) cobalt clusters. In the structures of compounds 1 and 2, a novel N(6)H(2) ligand formed by the in situ (2 + 3) cycloaddition of two azides was observed. Density functional theory (DFT) calculations give the heat of formation (2N(3)(-) + 2H(+) --> N(6)H(2)) and decomposition energy (N(6)H(2) --> 3N(2) + H(2)) of 677.47 and 124.85 kcal/mol, respectively. Furthermore, an intergradation was determined at the B3LYP/6-311++g(d,p) level for the formation of the N(6)H(2) ligand. In addition, one TC4A ligand of a sandwich unit adopts a cone conformation, while the other adopts a pinched cone conformation in 3. The magnetic properties of these three compounds were influenced mainly by the orbital contributions of the distorted octahedral Co(II) ions.

Thiacalix[4]arene-supported planar Ln(4) (Ln = Tb(III), Dy(III)) clusters: toward luminescent and magnetic bifunctional materials.

This paper reports the syntheses, crystal structures, and luminescent and magnetic properties of four tetranuclear Tb(III) (1 and 3) and Dy(III) (2 and 4) complexes supported by p-phenylthiacalix[4]arene (H(4)PTC4A) and p-tert-butylthiacalix[4]arene (H(4)TC4A). All four frameworks can be formulated as [Ln(III)(4)(PTC4A/TC4A)(2)(mu(4)-OH)Cl(3)(CH(3)OH)(2)(H(2)O)(3)], and some methanol and water solvent molecules are occupied in the interstices. The compounds are featured with a sandwichlike unit constructed by two tail-to-tail calixarene molecules and a planar tetragonal (mu(4)-OH)Ln(4) cluster. The photoluminescent analyses suggest that there is an efficient ligand-to-Ln(III) energy transfer for compounds 1-3 and H(4)PTC4A is a more efficient "antenna" than H(4)TC4A. The Dy(III) compounds exhibit slow magnetic relaxation behavior of single-molecule magnet nature. The substitution of the t-Bu group with a phenyl group at the up-rim of thiacalix[4]arene leads to different extended structures and physical properties of as-synthesized compounds.

A {Co32} nanosphere supported by p-tert-butylthiacalix[4]arene.

Calixarene-capped Co(32) clusters are constructed by a sodalite Co(II)(24) cage and an encapsulated Co(III)(8) cube. The spherical units are arranged into three isomeric structures, two of which are stacked by the bcc lattices and the third of which is assembled by the cubic closest packing of the spherical units.