A 2D Layered Metal-Organic Framework Constructed by Using a Hexanuclear Manganese Metallamacrocycle as a Supramolecular Building Block

Synthesis of 2-Amino-N'-aroyl(het)arylhydrazides, DNA Photocleavage, Molecular Docking and Cytotoxicity Studies against Melanoma CarB Cell Lines

Diacylhydrazine bridged anthranilic acids with aryl and heteroaryl domains have been synthesized as the open flexible scaffold of arylamide quinazolinones in order to investigate flexibility versus rigidity towards DNA photocleavage and sensitivity. Most of the compounds have been synthesized via the in situ formation of their anthraniloyl chloride and subsequent reaction with the desired hydrazide and were obtained as precipitates, in moderate yields. All compounds showed high UV-A light absorption and are eligible for DNA photocleavage studies under this "harmless" irradiation. Despite their reduced UV-B light absorption, a first screening indicated the necessity of a halogen at the p-position in relation to the amine group and the lack of an electron-withdrawing group on the aryl group. These characteristics, in general, remained under UV-A light, rendering these compounds as a novel class of UV-A-triggered DNA photocleavers. The best photocleaver, the compound 9, was active at concentrations as low as 2 μΜ. The 5-Nitro-anthranilic derivatives were inactive, giving the opposite results to their related rigid quinazolinones. Molecular docking studies with DNA showed possible interaction sites, whereas cytotoxicity experiments indicated the iodo derivative 17 as a potent cytotoxic agent and the compound 9 as a slight phototoxic compound.

Layer like porous materials with hierarchical structure

Many chemical compositions produce layered solids consisting of extended sheets with thickness not greater than a few nanometers. The layers are weakly bonded together in a crystal and can be modified into various nanoarchitectures including porous hierarchical structures. Several classes of 2-dimensional (2D) materials have been extensively studied and developed because of their potential usefulness as catalysts and sorbents. They are discussed in this review with focus on clays, layered transition metal oxides, silicates, layered double hydroxides, metal(iv) phosphates and phosphonates, especially zirconium, and zeolites. Pillaring and delamination are the primary methods for structural modification and pore tailoring. The reported approaches are described and compared for the different classes of materials. The methods of characterization include identification by X-ray diffraction and microscopy, pore size analysis and activity assessment by IR spectroscopy and catalytic testing. The discovery of layered zeolites was a fundamental breakthrough that created unprecedented opportunities because of (i) inherent strong acid sites that make them very active catalytically, (ii) porosity through the layers and (iii) bridging of 2D and 3D structures. Approximately 16 different types of layered zeolite structures and modifications have been identified as distinct forms. It is also expected that many among the over 200 recognized zeolite frameworks can produce layered precursors. Additional advances enabled by 2D zeolites include synthesis of layered materials by design, hierarchical structures obtained by direct synthesis and top-down preparation of layered materials from 3D frameworks.

Delicate modulated assembly of a new kind of trinuclear copper(ii) motif governed by N-containing agents

A new kind of trinuclear cupric motif was preparedin situby adopting a novel multidentate bihydrazide ligand, leading to five assembly styles that were governed by N-containing agents.

Synthesis and Structural Characterization of a Metal Cluster and a Coordination Polymer Based on the [Mn(6)(mu(4)-O)(2)] Unit

A new 1-D coordination polymer {[Mn₆O₂(O₂CMe)₁₀(H₂O)₄]·2.5H₂O}_∞ (1·2.5H₂O)_∞ and the cluster [Mn₆O₂(O₂(O₂CPh)₁₀ (py)₂(MeCN)(H₂O)]·2MeCN (2·2MeCN) are reported. Both compounds were synthesized by room temperature reactions of [Mn₃(μ₃-O)(O₂CR)₆(L)₂(L′)] (R = Me, L = L′ = py, (1·2.5H₂O)_∞; R = Ph, L = py, L′ = H₂O, 2·2MeCN) in the presence of 3-hydroxymethylpyridine (3hmpH) in acetonitrile. The structures of these complexes are based on hexanuclear mixed-valent manganese carboxylate clusters containing the [Mn₄^IIMn₂^III(μ₄-O)₂]¹⁰⁺ structural core. (1·2.5H₂O)_∞ consists of zigzag chain polymers constructed from [Mn₆O₂(O₂CMe)₁₀(H₂O)₄] repeating units linked through acetate ligands, whereas 2·2MeCN comprises a discrete Mn₆-benzoate cluster.