Enhanced Proton Conductivity Promoted by Structural Transition in a 2D Interwoven Metal-Organic Framework.

We report enhanced proton conductivity promoted by a structural phase transition of MFM-504(Cu)-DMF to MFM-504(Cu)-MeOH and to MFM-504(Cu)-OH via ligand substitution upon exposure to MeOH and HO vapors, respectively. MFM-504(Cu)-DMF can be synthesized by the solvothermal reaction of Cu(NO)·3HO and the flexible zwitterionic ligand, imidazolium-1,3-bis(methylenedicarboxylate) (imidc), to afford a unique layered interwoven network structure. MFM-504(Cu)-OH shows a proton conductivity of 5.

Implementing magnetic properties on demand with a dynamic lanthanoid-organic framework.

We present the synthesis of a lanthanoid-organic framework (LOF) featuring a dynamic structure that exhibits tunable magnetic properties. The LOF undergoes breathing and gate-opening phenomena in response to changes in DMF content and N sorption, leading to the emergence of new crystal phases with distinct characteristics. Notably, the desolvated form of the LOF excels as a single-ion magnet, while the fully activated structure demonstrates impressive qubit properties, exhibiting Rabi oscillations up to 60 K.

Cooperative intra- and intermolecular hydrogen bonding in scaffolded squaramide arrays.

The structural, self-assembly and binding properties of oligo-(phenylene-ethynylene) (OPE) rigid rods linked to squaramides (SQs) have been studied and correlated with rod length. In the solid-state, OPE-SQ conjugates form indefinite arrays of head-to-tail hydrogen bonded SQs, arrays that include both intra- and intermolecular hydrogen bonds. In dichloromethane solution, intramolecularly hydrogen bonded SQ chains show cooperative polarisation, an effect that increases with OPE-SQ length.

Unsaturated chiral-only-at-metal rhodium(III) complexes bearing SiN-type ligands.

Enantiopure chiral-at-metal rhodium(III) unsaturated 16e complexes have been obtained from racemic [Rh(SiN)Cl] (SiN= 8-(dimethylsilyl)quinoline) using a readily accessible chiral spiroborate as chiral resolution agent. This strategy allows an easy access to enantiopure neutral Δ/Λ-Rh(SiN)2Cl and cationic Δ/Λ-Rh(SiN)2[BAr4F] unsaturated complexes, wherein rhodium(III) is coordinated to two inert silylquinoline ligands in a propeller-like arrangement.

Structural determination of oleanane-28,13β-olide and taraxerane-28,14β-olide fluoro-lactonization products from the reaction of oleanolic acid with Selectfluor.

The X-ray crystal structure data of 12-α-fluoro-3β-hy-droxy-olean-28,13β-olide methanol hemisolvate, 2CHFO·CHOH, (), and 12-α-fluoro-3β-hy-droxy-taraxer-28,14β-olide methanol hemisolvate, 2CHFO·CHOH, (), are described. The fluoro-lactonization of oleanolic acid using Selectfluor yielded a mixture of the six-membered δ-lactone () and the unusual seven-membered γ-lactone () following a 1,2-shift of methyl C-27 from C-14 to C-13.

-Silanide f-Block Complexes: Insights into Paramagnetic Influence on NMR Chemical Shifts.

The paramagnetism of f-block ions has been exploited in chiral shift reagents and magnetic resonance imaging, but these applications tend to focus on H NMR shifts as paramagnetic broadening makes less sensitive nuclei more difficult to study. Here we report a solution and solid-state (ss) Si NMR study of an isostructural series of locally -symmetric early f-block metal(III) -hypersilanide complexes, [M{Si(SiMe)}(THF)] (; M = La, Ce, Pr, Nd, U); were also characterized by single crystal and powder X-ray diffraction, EPR, ATR-IR, and UV-vis-NIR spectroscopies, SQUID magnetometry, and elemental analysis. Only one SiMe signal was observed in the Si ssNMR spectra of , while two SiMe signals were seen in solution Si NMR spectra of and .

A family of Cd(II) coordination polymers constructed from 6-aminopicolinate and bipyridyl co-linkers: study of their growth in paper and photoluminescence sensing of Fe and Zn ions.

In this work, we report on five novel coordination polymers (CPs) based on the linkage of the [Cd(6apic)] building block [where 6apic = 6-aminopicolinate] by different bipyridine-type organic spacers, forming different coordination compounds with the following formulae: [Cd(μ-6apic)] (1), {[Cd(6apic)(μ-bipy)]·HO} (2), {[Cd(6apic)(μ-bpe)]·2HO} (3), [Cd(6apic)(μ-6apic)(μ-bpa)] (4) and {[Cd(6apic)(μ-tmbp)]·7HO} (5) [where bipy = 4,4'-bipyridine, bpe = 1,2-di(4-pyridyl)ethylene, bpa = 1,2-di(4-pyridyl)ethane (bpa) and tmbp = 1,3-di(4-pyridyl)propane]. Most of the synthesized compounds form infinite metal-organic rods through the linkage of the building block by the bipyridine-type linker, except in the case of compound 4 whose assembly forms a densely packed 3D architecture. All compounds were fully characterized and their photoluminescence properties were studied experimentally and computationally through density functional theory (DFT) calculations.

Cerium(III) and 5-methylisophthalate-based MOFs with slow relaxation of magnetization and photoluminescence emission.

Two novel Ce(III) metal organic frameworks (MOFs) with formulas [Ce(5Meip)(H-5Meip)]GR-MOF-17 and [CeCl(5Meip)(DMF)]GR-MOF-18 (5Meip = 5-methylisophthalate, DMF = ,-dimethylformamide) have been synthesized, forming 3-dimensional frameworks. Magnetic measurements show that both compounds present field-induced slow magnetic relaxation under a small applied dc field. For GR-MOF-17, the temperature dependence of relaxation times is best described by a Raman mechanism, whereas for GR-MOF-18, relaxation occurs through a combination of Raman and local-mode pathways.

Synthesis, Characterization, and Catalytic Performance of a New Heterobimetallic Y/Tb Metal-Organic Framework with High Catalytic Activity.

A three-dimensional heterobimetallic porous structure with the formula {[YTbL(OH)(HO) (DMF)] ·1.5HO·DMF} (L = 3-amino-4-hydroxybenzoate) () has been synthesized and characterized by single crystal and powder X-ray diffraction, scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), inductively coupled plasma mass spectrometry (ICP-MS), electrophoretic mobility, and Fourier transform infrared (FTIR) spectroscopy. The structure presents two metal environments: a bioaugmented isosceles wedge (mm2) MO and a tricapped trigonal prism (-6m2) MNO.

Two- and Three-Spin Hybrid Inorganic-Organic [2]Rotaxanes Containing Metallated Salen Groups.

Mono- and bis-salen functionalised [2]rotaxanes have been synthesised from the esterification of [2]rotaxanes containing phenol-terminated threads (salen=N,N'-bis(salicylidene)ethylenediamine). The [2]rotaxanes have general formula [RH][CrNiF(OCBu)], where [RH] is a thread with a central secondary ammonium site that templates a [CrNiF(OCBu)] ring. The threads are terminated at one or both ends by carboxylic acid functionalised salen groups.

Modulating anti-inflammatory and anticancer properties by designing a family of metal-complexes based on 5-nitropicolinic acid.

A new family of six complexes based on 5-nitropicolinic acid (5-npic) and transition metals has been obtained: [M(5-npic)] (M = Mn (1) and Cd (2)), [Cu(5-npic)] (3), and [M(5-npic)(HO)] (M = Co (4), Ni (5), and Zn (6)), which display 1D, 2D, and mononuclear structures, respectively, thanks to different coordination modes of 5-npic. After their physicochemical characterization by single-crystal X-ray diffraction (SCXRD), elemental analyses (EA), and spectroscopic techniques, quantum chemical calculations using Time-Dependent Density Functional Theory (TD-DFT) were performed to further study the luminescence properties of compounds 2 and 6. The potential anticancer activity of all complexes was tested against three tumor cell lines, B16-F10, HT29, and HepG2, which are models widely used for studying melanoma, colon cancer, and liver cancer, respectively.

Direct Observation of Enhanced Iodine Binding within a Series of Functionalized Metal-Organic Frameworks with Exceptional Irradiation Stability.

Optimization of active sites and stability under irradiation are important targets for sorbent materials that might be used for iodine (I) storage. Herein, we report the direct observation of I binding in a series of Cu(II)-based isostructural metal-organic frameworks, MFM-170, MFM-172, MFM-174, NJU-Bai20, and NJU-Bai21, incorporating various functional groups (-H, -CH, - NH, -C≡C-, and -CONH-, respectively). MFM-170 shows a reversible uptake of 3.

Multifunctional Amino Acid Derivative Coordination Compounds: Novel Contrast Agent and Luminescence Materials.

In this work a family of multidimensional (2-(1H-tetrazol-5-yl)ethyl) amino acid coordination compounds have been synthesized and thoroughly characterized. For this purpose, glycine, valine, phenylalanine and tyrosine have been selected as starting amino acids and Mn, Zn and Cd as metallic nodes. From one side, for Mn based dimer magnetic resonance imaging studies have been conducted, prompted by the number and disposition of the coordinated water molecules and taking into consideration the promising future of manganese-based coordination compounds as bio-compatible substitutes to conventional Gd based contrast agents.

Studying Cation Exchange in {CrCo} Pseudorotaxanes: Preparatory Studies for Making Hybrid Molecular Machines.

In the design of dynamic supramolecular systems used in molecular machines, it is important to understand the binding preferences between the macrocycle and stations along the thread. Here, we apply H NMR spectroscopy to investigate the relative stabilities of a series of linear alkylammonium templated pseudorotaxanes with the general formula [HNRR'][CrCoF(OCCH Bu)] by exchanging the cation in solution. Our results show that the pseudorotaxanes are able to exchange threads via a dissociative mechanism.

An air- and moisture-stable ruthenium precatalyst for diverse reactivity.

Versatile, efficient and robust (pre)catalysts are pivotal in accelerating the discovery and optimization of chemical reactions, shaping diverse synthetic fields such as cross-coupling, C-H functionalization and polymer chemistry. Yet, their scarcity in certain domains has hindered the advancement and adoption of new applications. Here we present a highly reactive air- and moisture-stable ruthenium precatalyst [(BuCN)Ru(HO)](BF), featuring a key exchangeable water ligand.

Disorder and Sorption Preferences in a Highly Stable Fluoride-Containing Rare-Earth -Type Metal-Organic Framework.

Rare-earth (RE) metal-organic frameworks (MOFs) synthesized in the presence of fluorine-donating modulators or linkers are an important new subset of functional MOFs. However, the exact nature of the REX core of the molecular building block (MBB) of the MOF, where X is a μ-bridging group, remains unclear. Investigation of one of the archetypal members of this family with the stable framework topology, Y-fum--MOF (), using a combination of experimental techniques, including high-field (20 T) solid-state nuclear magnetic resonance spectroscopy, has determined two sources of framework disorder involving the μ-X face-capping group of the MBB and the fumarate (fum) linker.

Synthesis and Magnetic Properties of Bis-Halobenzene Decamethyldysprosocenium Cations.

The decamethyldysprosocenium cation, [Dy(Cp*)] (Cp* = {CMe}), was a target single-molecule magnet (SMM) prior to the isolation of larger dysprosocenium cations, which have recently shown magnetic memory effects up to 80 K. However, the relatively short Dy···Cp* distances of [Dy(Cp*)], together with the reduced resonance of its vibrational modes with electronic states compared to larger dysprosocenium cations, could lead to more favorable SMM behavior. Here, we report the synthesis and magnetic properties of a series of solvated adducts containing bis-halobenzene decamethyldysprosocenium cations, namely [Dy(Cp*)(PhX-κ-)][Al{OC(CF)}] (X = F or Cl) and [Dy(Cp*)(CHF-κ-,)(CHF-κ-)][Al{OC(CF)}].

Stepwise Operation of a Molecular Rotary Motor Driven by an Appel Reaction.

To date, only a small number of chemistries and chemical fueling strategies have been successfully used to operate artificial molecular motors. Here, we report the 360° directionally biased rotation of phenyl groups about a C-C bond, driven by a stepwise Appel reaction sequence. The motor molecule consists of a biaryl-embedded phosphine oxide and phenol, in which full rotation around the biaryl bond is blocked by the P-O oxygen atom on the rotor being too bulky to pass the oxygen atom on the stator.

Isolation of a Bent Dysprosium Bis(amide) Single-Molecule Magnet.

The isolation of formally two-coordinate lanthanide (Ln) complexes is synthetically challenging, due to predominantly ionic Ln bonding regimes favoring high coordination numbers. In 2015, it was predicted that a near-linear dysprosium bis(amide) cation [Dy{N(SiPr)}] could provide a single-molecule magnet (SMM) with an energy barrier to magnetic reversal () of up to 2600 K, a 3-fold increase of the record for a Dy SMM at the time; this work showed a potential route to SMMs that can provide high-density data storage at higher temperatures. However, synthetic routes to a Dy complex containing only two monodentate ligands have not previously been realized.

Evaluation of heteroscorpionate ligands as scaffolds for the generation of Ruthenium(II) metallodrugs in breast cancer therapy.

The modular synthesis of the heteroscorpionate core is explored as a tool for the rapid development of ruthenium-based therapeutic agents. Starting with a series of structurally diverse alcohol-NN ligands, a family of heteroscorpionate-based ruthenium derivatives was synthesized, characterized, and evaluated as an alternative to platinum therapy for breast cancer therapy. In vitro, the antitumoral activity of the novel derivatives was assessed in a series of breast cancer cell lines using UNICAM-1 and cisplatin as metallodrug control.