Tubular glassy carbon microneedles with fullerene-like tips for biomedical applications

Glassy carbon, in general, is made by the pyrolysis of polymeric materials and has been the subject of research for at least fifty years. However, as understanding its microstructure is far from straightforward, it continues to be an area of active research. Glassy carbon adopts different allotropes depending on the hybridizations of the C–C bond, that is, sp, sp2, or sp3. Furthermore, a variety of short-range ordering effects can interact with each other and this, along with the effects of microporosity, grain boundaries, and defects, render this a fascinating material. Following the nanoarchitectonics concept of bottom-up creation of functional materials, we use methane rather than a polymer to form glassy carbon. Here we show that tubular glassy carbon microneedles with fullerene-like tips form when methane undergoes pyrolysis on a curved alumina surface. X-ray diffraction of these glassy carbon tubules shows long-range order with a d-spacing of 4.89 Å, which is indicative of glassy carbon. Raman spectroscopy shows the material to be graphitic in nature, and SEM shows the fullerene-like structure of the material. This work provides new insights into the structure of glassy carbons relevant to the application of glassy carbons as a biomaterial, for example, as a new form of carbon-based microneedles. Since metallic needles can introduce toxic/allergenic species into susceptible subjects, this alternative carbon-based microneedle form has great potential as a replacement biomedical material for metallic needles in the field of neural engineering and as acupuncture needles

Recent bio-advances in metal-organic frameworks

Metal-organic frameworks (MOFs) have found uses in adsorption, catalysis, gas storage and other industrial applications. Metal Biomolecule Frameworks (bioMOFs) represent an overlap between inorganic, material and medicinal sciences, utilising the porous frameworks for biologically relevant purposes. This review details advances in bioMOFs, looking at the synthesis, properties and applications of both bioinspired materials and MOFs used for bioapplications, such as drug delivery, imaging and catalysis, with a focus on examples from the last five years

A 12-fold ths interpenetrated network utilizing a glycine-based pseudopeptidic ligand

We report the synthesis and characterization of a 3D Cu(II) coordination polymer, [Cu3(L1)2(H2O)8]·8H2O (1), with the use of a glycine-based tripodal pseudopeptidic ligand (H3L1 = N,N’,N’’-tris(carboxymethyl)-1,3,5-benzenetricarboxamide or trimesoyl-tris-glycine). This compound presents the first example of a 12-fold interpenetrated ths net. We attempt to justify the unique topology of 1 through a systematic comparison of the synthetic parameters in all reported structures with H3L1 and similar tripodal pseudopeptidic ligands. We additionally explore the catalytic potential of 1 in the A3 coupling reaction for the synthesis of propargylamines. The compound acts as a very good heterogeneous catalyst with yields up to 99% and loadings as low as 3 mol%

Synthesis, characterization, magnetic properties, and topological aspects of isoskeletal heterometallic hexanuclear Co II 4 Ln III 2 coordination clusters possessing 2,3,4M6-1 Topology

The reaction of (E)-2-(2-hydroxy-3-methoxybenzylideneamino)phenol (H2L1) with Co(NO3)26H2O and LnCl3x(H2O) afforded a family of hexanuclear heterometallic coordination clusters (CCs) formulated as [CoII4LnIII2(µ3-OH)2(L1)4Cl2(NO3)2(MeOH)4] 3(Et2O) where Ln is Y (1), Gd (2), Dy (3), and Tb (4). All the compounds are stable in solution as confirmed by ESI-MS studies. The compounds can be described as twisted boat-like and possess a 2,3,4M6–1 topology. The reaction of (E)-2-(5-bromo-2-hydroxy-3-methoxybenzylideneamino)phenol (H2L2) with Co(NO3)26H2O and DyCl3x(H2O) afforded [CoII4DyIII2(µ3-OH)2(L2)4Cl2(NO3)2(MeOH)4] (5), which is isoskeletal to compounds 1–4. Magnetic studies performed over the temperature range 1.8–300 K show that compound 3 undergoes slow magnetic relaxation

Unprecedented chemical transformation: crystallographic evidence for 1,1,2,2-tetrahydroxyethane captured within an Fe6Dy3 single molecule magnet

A nonanuclear {Fe6Dy3} coordination cluster displaying SMM behaviour in which an unprecedented chemical transformation provides structural information for the existence of 1,1,2,2-tetrahydroxyethane is reported

Synthesis and Supramolecular Structure of a (5-(3-(1H-tetrazol-5-yl)phenyl)-1H-tetrazole) Cobalt Complex

The reaction of CoCl2·6H2O with m-BDTH2 (1,3-benzeneditetrazol-5-yl) leads to [Co(C8H6N8)2(H2O)2(CH3CN)2]Cl2 (1). Both tetrazolic groups remain protonated existing in a 1H tautomeric form. A trifurcated chlorine atom and stacking interactions assemble compound 1 into a three-dimensional network

Isoskeletal Schiff base polynuclear coordination clusters: synthetic and theoretical aspects

This work addresses and enlightens synthetic aspects derived from our effort to systematically construct isoskeletal tetranuclear coordination clusters (CCs) of the general formula [TR2Ln2(LX)4(NO3)2(solv)2] possessing a specific defected dicubane topology, utilizing various substituted Schiff base organic ligands (H2LX) and NiII/CoII and Dy(OTf)3 salts. Our synthetic work is further supported by DFT studies

Dinuclear Lanthanide (III) coordination polymers in a domino reaction

A systematic study was performed to further optimise the catalytic room-temperature synthesis of trans-4,5- diaminocyclopent-2-enones from 2-furaldehyde and primary or secondary amines under a non-inert atmosphere. For this purpose, a series of dinuclear lanthanide (III) coordination polymers were synthesised using a dianionic Schiff base and their catalytic activities were investigated

Tetranuclear Zn2Ln2 coordination clusters as catalysts in Petasis borono-Mannich multicomponent reaction

We report herein for the first time the efficiency of heteronuclear Zn/Ln coordination clusters (CCs) as catalysts for the multicomponent Mannich-type condensation that involves amines, aldehydes and boronic acids, known as Petasis borono-Mannich (RBR) reaction. The reaction proceeds in very good to excellent yields (84-98%, 17 products) at room temperature with catalyst loadings as low as 1.0 mol%