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By incorporating photoreactive anthracene moieties into binuclear Dy

HIV-1 reverse transcriptase (RT) inhibitors are fundamental to the discovery and development of anti-HIV drugs. Their main target is RT, and only a tiny number of them can bind to viral RNA. In this paper, five new Zn(II) porphyrin compounds were developed with different characters.

Reaction of the metalloligand IrIII(ppy-COOH)3 and the anisotropic paramagnetic CoII ion under solvothermal conditions resulted in a metal-metalloligand coordination polymer, [CoII3(μ3-O)(μ-OH2){IrIII(ppy-COO)2(ppy-COOH)}2(H2O)4]·2DMF·xH2O (I). It consists of trimeric Co3O secondary building units (SBUs) bridged by pairs of Ir to form chains of alternate orthogonal squares. The compound undergoes two single-crystal to single-crystal transformations while retaining its general structural features. A chemical transformation occurs to give [CoII3(μ3-O){IrIII(ppy-COO)2(ppy-COOH)}2(H2O)4(DMF)]·DMF·H2O (II) by soaking in acetone, where a bridging water molecule departs and the solvent DMF bonds to the vacant site of the Co center. Both I and II undergo a temperature-induced transformation to [CoII3(μ3-O){IrIII(ppy-COO)2(ppy-COOH)}2(H2O)3(DMF)]·DMF (III), where one more coordinated water molecule is lost. The major difference in the three phases is in the Co coordination spheres, which have considerable consequences on the magnetism. Compound I displays paramagnetism down to 2 K, whereas II and III show weak ferromagnetism with TC values of 14 and 17 K, respectively.

By virtue of its magnetic moment and variable valencies, the D4h paddlewheel ruthenium dimer is a desirable molecular building block for the construction of functional networks. If in addition to the Ru open axial site the organic ligand is designed to allow transversal connections, a wider range of structural possibilities is expected. The organic ligand can also be modified to introduce other functionalities. In the present study we employed a diphosphonate containing a protonated amine, 1-ammoniummethylenediphosphonate [NH3CH(PO3)23-; (Hamdp)], as the ligand to construct paddlewheel Ru2(Hamdp)2 building block. Three networks of different structural dimensionalities were obtained. (H3O)2[RuII2(Hamdp)2] (1) forms one-dimensional chain of S = 1 RuII2 bridged at axial positions through Ru-O bonds. From 1 as a starting material, its reaction with lanthanide ions results in the bimetallic Dy(H2O)3[Ru2(Hamdp)2][Ru2(Hamdp)2(H2O)2][Ru2(Hamdp)(amdp)]0.5·12H2O (2), which has a pillared-bilayer structure and Yb[Ru2(Hamdp)2]2[Ru2(Hamdp)2(H2O)2]·15H2O (3), which is a three-dimensional open framework, both contain mixed-valent RuII/III2 units and show new connection topologies of the Ru2 dimers. After activation 2 does not adsorb N2 and CO2 but takes up 12 H2O. In contrast, 3 take up all three gases. The optimum proton conductivities were moderate reaching 1.44 × 10-6 for 2 and 0.93 × 10-5 S cm-1 for 3 at 95% relative humidity and 55 °C.

Iridium(IV) oxides have gained increased attention in recent years owing to the presence of competing spin–orbit coupling and Coulomb interactions, which facilitate the emergence of novel quantum phenomena. In contrast, the electronic structure and magnetic properties of IrIV-based molecular materials remain largely unexplored. In this paper, we take a fresh look at an old but puzzling compound, Na2IrCl6, which can be hydrated to form two stable phases with formulas Na2IrCl6·2H2O and Na2IrCl6·6H2O. Their crystal structures are well illustrated based on X-ray powder diffraction data. Magnetic studies reveal that Na2IrCl6 and Na2IrCl6·2H2O are canted antiferromagnets with ordering temperatures of 7.4 and 2.7 K, respectively, whereas Na2IrCl6·6H2O is paramagnetic down to 1.8 K. First-principle calculations on Na2IrCl6 reveal a Jeff = 1/2 ground state, and the band structures show that Na2IrCl6 is a spin–orbital-induced semiconductor with an indirect gap of about 0.18 eV.

Four pairs of enantiomeric dysprosium(III) phosphonates, namely, R- or S-[Dy3(pempH2)2(pempH)7]2(NO3)4·12H2O (R-1 or S-1), R- or S-[Dy3(pempH)7(pempH2)2]Cl2·2H2O (R-2 or S-2), R- or S-[Dy3(pempH)7(pempH2)2]Br2·2H2O (R-3 or S-3), and R- or S-[Dy11(pempH2)6(pempH)27](CF3SO3)6·22H2O (R-4 or S-4) are reported, where R- or S-pempH2 represent R- or S-(1-phenylethyl)amino] methylphosphonic acid. All show homochiral chain structures, charge-balanced by counteranions. A comparison of the crystal morphologies of the R-isomers reveals that the overall shapes are quite similar for the four compounds, but the aspect ratio changes remarkably following the sequence: R-1 < R-2 < R-3 < R-4. The sequence is in agreement with the decreasing interchain interactions related to different counteranions, which is rationalized by molecular simulations. The counteranions also influence the intrachain structures and the local coordination environments of the DyIII ions. As a result, compounds R-2 and R-3 exhibit distinct dual relax...

Three iridium(III)-based metal–organic frameworks (MOFs), namely [Cd3{Ir(ppy-COO)3}2(DMF)2(H2O)4]·6H2O·2DMF (1), [Cd3{Ir(ppy-COO)3}2(DMA)2(H2O)2]·0.5H2O·2DMA (2), and [Cd3{Ir(ppy-COO)3}2(DEF)2(H2O)2]·8H2O·2DEF (3) (ppy-COOH = methyl-3-(pyridin-2-yl)benzoic acid, DMF = N,N-dimethylformamide, DMA = N,N-dimethylacetamide, DEF = N,N-diethylformamide), have been synthesized and characterized. Single-crystal structural determinations reveal that compounds 1–3 are isostructural, showing a three-dimensional framework structure with (3,6) connected rtl topologyin whose trimers of {Cd3(COO)6} are cross-linked by Ir(ppy-COO)33–. The structures are completely different from those of other Ir(III)-based MOFs. Compound 1 was selected for a detailed study on sensing properties. The excellent luminescence as well as good water stability of 1 makes it a highly selective and sensitive multiresponsive luminescent sensor for Fe3+ and Cr2O72–. The detection limits are 67.8 and 145.1 ppb, respectively. Compound 1 can also be u...

By virtue of its magnetic moment and variable valencies, the

Iridium(IV) oxides have gained increased attention in recent years owing to the presence of competing spin-orbit coupling and Coulomb interactions, which facilitate the emergence of novel quantum phenomena. In contrast, the electronic structure and magnetic properties of Ir

Three iridium(III)-based metal-organic frameworks (MOFs), namely [Cd

A polar cobalt(II) phosphonate Co(bamdpH2)(H2O) (1) [bamdpH4 = (benzylazanediyl)bis(methylene)diphosphonic acid] is reported. It shows a linear chain structure. The neighboring chains are connected by moderately strong hydrogen bonds forming a supramolecular layer. The interlayer spaces are filled with the organic groups of the phosphonate ligands. Compound 1 displays the coexistence of single-chain magnet behavior and canted antiferromagnetism below 2.8 K. Moreover, the magnetic dynamics is strongly dependent on the synthetic methods, a phenomenon that has not been documented before.

By using an achiral (4-carboxynaphthalen-1-yl)phosphonic acid (4-cnappH3), compound Co2(4-cnapp)(OH)(H2O)2 (1) is isolated crystallizing in orthorhomibic space group P212121. It shows a three-dimensional framework structure in which the Δ-type chains of corner-sharing Co3(μ3-OH) triangles are cross-linked by the organic groups of the phosphonate ligands. Interestingly, the bulk sample of compound 1 is enantioenriched, thus providing a rare example of symmetry breaking upon crystallization from achiral starting materials. Slow magnetization relaxation is observed at low temperature.

The synthesis and properties of phosphorus(V) 5,10,15-tris(4-methoxycarbonylphenyl)corrole (1) have been investigated, and its potential utility for bioimaging applications in living cells has been explored. As would normally be anticipated for corrole complexes, the intensity of the Q(0,0) bands of 1 is greater than those of comparable phosphorus(V) tetraphenylporphyrins, but the ΦF values (0.25 for 1) are found to be comparable. A detailed analysis of the electronic structure of the complex was carried out by comparing electronic absorption and MCD spectral data to the results of TD-DFT calculations. The meso-aryl substituents, which enhance the lipophilicity of 1 and hence result in its localization in intracellular membranes during HeLa cell experiments, are predicted to result in a narrowing of the HOMO-LUMO gap and hence a red shift of the Q(0,0) bands toward the optical window in biological tissues.

This Paper reports the first examples of O-P-O bridged Mn2(salen)2 (salen = N,N'-bis(salicylidene)ethylenediamine) chain compounds, namely, [Mn2(salen)2(2-FC6H4PO3H)](ClO4)·1/2CH3OH (1) and [Mn2(salen)2(4-FC6H4PO3H)](ClO4) (2). The phosphonate ligands adopt a syn-anti bidentate bridging mode in 1 and a syn-syn bidentate bridging mode in 2, originated from the isomeric phosphonate ligands. The different bridging modes cause a significant change in the Mn-O···O-Mn torsion angle over the O-P-O bridge, which are 96.6 and 1.9° for 1 and 2, respectively. As a result, the antiferromagnetic (AF) exchange couplings mediated through the O-P-O pathway are extremely weak in 1, and the overall magnetic behaviors are dominated by the Mn2(salen)2 moieties. Single-molecule magnetic behavior is observed in 1. For compound 2, the AF interaction over the O-P-O bridge is much stronger. The coexistence of metamagnetism and single-chain magnetic behavior is observed for 2.

Four lanthanide compounds with formulas [Cs{Dy(hfac)4}] (1), [Cs{Er(hfac)4}] (2), [K{Dy(hfac)4}] (3), and [K{Er(hfac)4}] (4) (hfac = hexafluoroacetylacetone) are reported. Compounds 1 and 2 crystallize in the orthorhombic Pbcn space group, while 3 and 4 are in the triclinic P1̅ space group. All display chain structures in which the mononuclear [Ln(hfac)4](-) anions are linked by alkali metal ions. However, the coordination geometries around the Ln atoms are quite different depending on the cation. They adopt a distorted dodecahedron with pseudo-D2d symmetry in the cesium compounds 1 and 2, while a distorted square-antiprism with pseudo-D4d symmetry is adopted in the potassium compounds 3 and 4. The latter compounds show distinct field-induced slow magnetization relaxation. The energy barriers are 23.95 and 20.21 K for compounds 3 and 4, respectively.

A series of layered lanthanide phosphonates α-Ln(2-qpH)(SO4)(H2O)2 (α-Ln; Ln = Gd, Tb, Ho, Er) and β-Ln(2-qpH)(SO4)(H2O)2 (β-Ln; Ln = Gd, Tb, Ho, Er, Yb) (2-qpH2 = 2-quinolinephosphonic acid) have been synthesized and characterized. Compounds α-Ln crystallize in monoclinic space group P21/c, while compounds β-Ln crystallize in triclinic space group P1̅. Magnetic studies reveal that dominant ferromagnetic interactions are propagated between the magnetic centers in all cases. Field-induced magnetic relaxation is observed in compounds β-Er and β-Yb.