Conversion from Heterometallic to Homometallic Metal-Organic Frameworks.

Two new heterometallic metal-organic frameworks (MOFs), LnZnTPO 1 and 2, and two homometallic MOFs, LnTPO 3 and 4 (Ln=Eu for 1 and 3, and Tb for 2 and 4; H TPO=tris(4-carboxyphenyl)phosphine oxide) were synthesized, and their structures and properties were analyzed. They were prepared by solvothermal reaction of the C -symmetric ligand H TPO with the corresponding metal ion(s) (a mixture of Ln and Zn for 1 and 2, and Ln alone for 3 and 4). Single-crystal XRD (SXRD) analysis revealed that 1 and 3 are isostructural to 2 and 4, respectively.

Humidity-triggered single-crystal-to-single-crystal structural transformations in a Zn(ii) coordination polymer displaying unusual activation energy change in proton conductivity.

Single-crystal-to-single crystal structural conversions occur in a Zn(ii) coordination polymer, uniquely induced by fine-tuned relative humidity. Proton conductivity depends on the number of hydrogen bonds in the structures. Slope change in the Arrhenius plot is uncommon among coordination-based conductors and associated with temperature-dependent phase changes.

Opioid analgesics are the leading cause of adverse drug reactions in the obstetric population in South Korea.

Medication use during pregnancy is gradually increasing; however, the safety of this practice remains largely unknown.We investigated medications with the most adverse drug reactions (ADRs) among pregnant women and the clinical features of those medications.Reports of ADRs among pregnant women were extracted from the Korea Adverse Events Reporting System (January 2012-December 2015).

Reversible crystal-to-amorphous structural transformations and magnetic variations in single end-on azide-bridged M (M = Mn, Ni) coordination polymers.

M (M = Mn, Ni) coordination frameworks, singly linked by end-on azide ligands, were prepared by employing the long, flexible spacer ligand, p-XBP4. These two-dimensional layer structures underwent reversible crystal-to-amorphous phase transformations during the hydration-dehydration process. Moreover, the magnetic nature changes from antiferromagnetic to ferromagnetic coupling when moving from Mn to Ni.

Control of Interchain Antiferromagnetic Coupling in Porous Co(II)-Based Metal-Organic Frameworks by Tuning the Aromatic Linker Length: How Far Does Magnetic Interaction Propagate?

Three MOF-74-type Co(II) frameworks with one-dimensional hexagonal channels have been prepared. Co(II) spins in a chain are ferromagnetically coupled through carboxylate and phenoxide bridges. Interchain antiferromagnetic couplings via aromatic ring pathways operate over a Co-Co length shorter than ∼10.

Luminescent Metal-Organic Framework Sensor: Exceptional Cd Turn-On Detection and First In Situ Visualization of Cd Ion Diffusion into a Crystal.

With regard to fluorescence quenching commonly observed during metal-ion detection, "turn-on" chemical sensing has been rarely reported, but could be extremely important because it facilitates the selective recognition of target objects of interest against a dark background. A metal-organic framework (MOF) chemosensor has been prepared that serves as an efficient platform for the selective detection of Cu and Cd ions over other metal ions. In particular, this framework shows the highest fluorescence enhancement (≈60-fold relative to Cd-free MOF) for the hazardous metal ion Cd among luminescent MOFs and displays excellent reusability in repeated cycles.

Slow relaxation dynamics of a mononuclear Er(iii) complex surrounded by a ligand environment with anisotropic charge density.

Two sets of isostructural mononuclear compounds, [Ln(L)(HO)](PF) [1, Ln = Er; 3, Ln = Gd; L = CpCo{P(O)(O(CH))}] and Ln(L)(NO) (2, Ln = Er and 4, Ln = Gd), are synthesized by self-assembly of the respective lanthanide ions and tripodal chelate ligands. The Ln ions are encircled by two L ligands, and two water molecules or one nitrate anion. Each octacoordinated Ln center adopts a distorted square antiprism geometry.

Phase Transformation, Exceptional Quenching Efficiency, and Discriminative Recognition of Nitroaromatic Analytes in Hydrophobic, Nonporous Zn(II) Coordination Frameworks.

Five-fold interpenetrated Zn(II) frameworks (1 and 2) have been prepared, and an irreversible phase transformation from 1 to 2 is found to occur through a dissolution-recrystallization process. Compound 1 exhibits the highest quenching efficiency (>96%) for nitrobenzene at 7 ppm among luminescent coordination polymers. Selective discrimination of nitroaromatic molecules including o-nitrophenol (o-NP), p-nitrophenol (p-NP), 2,4-dinitrophenol (DNP), and 2,4,6-trinitrophenol (TNP) is realized in 1 and 2 as a result of the fact that the framework-analyte interaction affords characteristic emission signals.

Cost-Effective, High-Performance Porous-Organic-Polymer Conductors Functionalized with Sulfonic Acid Groups by Direct Postsynthetic Substitution.

We demonstrate the facile microwave-assisted synthesis of a porous organic framework 1 and the sulfonated solid (1S) through postsubstitution. Remarkably, the conductivity of 1S showed an approximately 300-fold enhancement at 30 °C as compared to that of 1, and reached 7.72×10  S cm at 80 °C and 90 % relative humidity.

Tuning of chain chirality by interchain stacking forces and the structure-property relationship in coordination systems constructed by meridional Fe cyanide and Mn Schiff bases.

We synthesized six Fe(iii)-Mn(iii) bimetallic compounds by self-assembling the newly developed mer-Fe cyanide PPh[Fe(Clqpa)(CN)]·HO (1) and PPh[Fe(Brqpa)(CN)]·HO (2) with Mn Schiff base Mn(5-Xsalen) cations. These compounds include [Fe(Xqpa)(CN)][Mn(5-Ysalen)]·pMeOH·qHO [qpaH = N-(quinolin-8-yl)picolinamide; salen = N,N'-ethylenebis(salicylideneiminato) dianion; X = Cl, Y = H (3); X = Cl, Y = Br (4); X = Br, Y = H (5); X = Br, Y = F (6); X = Br, Y = Cl (7); X = Br, Y = Br (8)]. When precursor 1 was used, compounds 3 and 4 were isolated to give a dinuclear entity and a linear chain structure, respectively.

Switching of Slow Magnetic Relaxation Dynamics in Mononuclear Dysprosium(III) Compounds with Charge Density.

The symmetry around a Dy ion is recognized to be a crucial parameter dictating magnetization relaxation dynamics. We prepared two similar square-antiprismatic complexes, [Dy(LOMe)2(H2O)2](PF6) (1) and Dy(LOMe)2(NO3) (2), where LOMe = [CpCo{P(O)(O(CH3))2}3], including either two neutral water molecules (1) or an anionic nitrate ligand (2). We demonstrated that in this case relaxation dynamics is dramatically affected by the introduction of a charged ligand, stabilizing the easy axis of magnetization along the nitrate direction.

Adsorption of Carbon Dioxide on Unsaturated Metal Sites in M2 (dobpdc) Frameworks with Exceptional Structural Stability and Relation between Lewis Acidity and Adsorption Enthalpy.

A series of metal-organic frameworks (MOFs) M2 (dobpdc) (M=Mn, Co, Ni, Zn; H4 dobpdc=4,4'-dihydroxy-1,1'-biphenyl-3,3'-dicarboxylic acid), with a highly dense arrangement of open metal sites along hexagonal channels were prepared by microwave-assisted or simple solvothermal reactions. The activated materials were structurally expanded when guest molecules including CO2 were introduced into the pores. The Lewis acidity of the open metal sites varied in the order MnZn, as confirmed by C=O stretching bands in the IR spectra, which are related to the CO2 adsorption enthalpy.

Exceptional CO working capacity in a heterodiamine-grafted metal-organic framework.

An amine-functionalized metal-organic framework (MOF), dmen-Mg(dobpdc) (dmen = ,-dimethylethylenediamine), which contains a heterodiamine with both primary and tertiary amines, was prepared a post-synthetic method. This material exhibits a significant selectivity factor for CO over N that is commensurate with top-performing MOFs. It is remarkable that the solid is fully regenerated under vacuum or flowing Ar at low desorption temperatures, and following this can take up CO at more than 13 wt%.

Superprotonic conductivity of a UiO-66 framework functionalized with sulfonic acid groups by facile postsynthetic oxidation.

Facile postsynthetic oxidation of the thiol-laced UiO-66-type framework UiO-66(SH)2 enabled the generation of UiO-66(SO3 H)2 with sulfonic acid groups covalently linked to the backbone of the system. The oxidized material exhibited a superprotonic conductivity of 8.4×10(-2)  S cm(-1) at 80 °C and 90 % relative humidity, and long-term stability of the conductivity was observed.

Synthesis, structures, and magnetic properties of end-to-end azide-bridged manganese(III) chains: elucidation of direct magnetostructural correlation.

The two one-dimensional chain compounds [Mn(L1)(N3)]·H2O (1·H2O; H2L1 = 2,2'-((1E,1'E)-ethane-1,2-diylbis(azan-1-yl-1-ylidene))bis(phenylmethan-1-yl-1-ylidene)diphenol) and [Mn(L2)(N3)] (2; H2L2 = 2,2'-((1E,1'E)-2,2-dimethylpropane-1,3-diyl)bis(azan-1-yl-1-ylidene)-bis(phenylmethan-1-yl-1-ylidene)diphenol) bridged by single end-to-end azides were prepared via a self-assembly process. Each Mn(III) ion exhibits a characteristic Jahn-Teller elongation along the chain direction. For both compounds, antiferromagnetic interactions between Mn(III) spins within a chain are transmitted through the azide ligands, together with the apparent occurrence of spin canting at low temperatures.