Facile Microwave-Assisted Synthesis of 2D Imine-Linked Covalent Organic Frameworks for Exceptional Iodine Capture.

Covalent organic frameworks (COFs) have emerged as auspicious porous adsorbents for radioiodine capture. However, their conventional solvothermal synthesis demands multiday synthetic times and anaerobic conditions, largely hampering their practical use. To tackle these challenges, we present a facile microwave-assisted synthesis of 2D imine-linked COFs, Mw-TFB-BD-X, (X = -CH3 and -OCH3) under air within just 1 h. The resultant COFs possessed higher crystallinity, better yields, and more uniform morphology than their solvothermal counterparts. Remarkably, Mw-TFB-BD-CH3 and Mw-TFB-BD-OCH3 exhibited exceptional iodine adsorption capacities of 7.83 g g-1 and 7.05 g g-1, respectively, placing them among the best-performing COF adsorbents for static iodine vapor capture. Moreover, Mw-TFB-BD-CH3 and Mw-TFB-BD-OCH3 can be reused 5 times with no apparent loss in the adsorption capacity. The exceptionally high iodine adsorption capacities and excellent reusability of COFs were mainly attributed to their uniform spherical morphology and enhanced chemical stability due to the in-built electron-donating groups, despite their low surface areas. This work establishes a benchmark for developing advanced iodine adsorbents that combine fast kinetics, high capacity, excellent reusability, and facile rapid synthesis, a set of appealing features that remain challenging to merge in COF adsorbents so far.

Modifying Electrical and Magnetic Properties of Single-Walled Carbon Nanotubes by Decorating with Iron Oxide Nanoparticles.

In this work, we report a facile approach to modify the magnetic and electrical property of Hipco single-walled carbon nanotubes (SWCNTs) by attaching iron oxide nanoparticles (FeNPs). The Raman spectra of FeNP-SWCNTs revealed an apparent intensity reduction of metallic peaks in Radial breathing mode (RBM) region, which indicates the ratio change between the metallic and semiconducting component of SWCNTs after modification. Distinctive magnetic and electric resistance properties of FeNP-SWCNTs were found to be associated with the different shapes of FeNPs. The specific FeNP examples as showcased in this work can be applied to tune the electric and magnetic properties of other nanostructured materials in general and shed light on various electronic and magnetic applications.

Mesoporous stilbene-based lanthanide metal organic frameworks: synthesis, photoluminescence and radioluminescence characteristics.

Ultra large pore isostructural metal organic frameworks (MOFs) which exhibit both photoluminescence and scintillation properties, were synthesized from trans-4,4'-stilbenedicarboxylic acid (H2L) and trivalent lanthanide (Ln) metal salts under solvothermal conditions (Ln = Er3+ (1) and Tm3+ (2)). This new class of mesoporous materials is a non-interpenetrating network that features ultra-large diamond shaped pores of dimensions with approximate cross-sectional dimensions of 28 Å × 12 Å. The fully deprotonated ligand, L, is isolated and rigidified as it serves as the organic linker component of the MOF structure. Its low density unit cells possess asymmetric units with two crystallographically independent Ln3+ ions in seven coordinate arrangements. A distinct feature of the structure is the bis-bidentate carboxylate groups. They serve as a ligand that coordinates two Ln(iii) ions while each L connects four Ln(iii) ions yielding an exceptionally large diamond-shaped rectangular network. The structure exhibits ligand-based photoluminescence with increased lifetime compared to free stilbene molecules on exposure to UV radiation, and also exhibits strong scintillation characteristics, comprising of both prompt and delayed radioluminescence features, on exposure to ionizing radiation.

Nano-Snowflower of Gold Nanoparticles-Ruthenium Metallopolymer-Carbon Nanotubes Binding Anti-DNP IgE Antibody.

Gold nanoparticles (AuNPs) have been chemically functionalized onto multiwalled carbon nanotubes (MWCNT) through a metallopolymer linker-bis (2,2':6'2"-terpyridine) ruthenium(II)-connected diblock poly(N-isopropyacryamide). A "nano-snowflower" pattern was formed by self-assembly MWCNT-AuNP nanocomposite with anti-DNP IgE antibody. MWCNT-AuNP nanohybrid has unique biocompatibility and electronic current-voltage properties. This nanohybrid shows the potential application for IgE biosensor to diagnose cancer cells. We represent a step towards building complex electronic circuits response by providing molecular recognition properties.

catena-Poly[{µ3-3,3'-[(1,7-dioxa-4,10-di-aza-cyclo-dodecane-4,10-di-yl)bis-(methyl-ene)]dibenzoato}cobalt(II)].

The title compound, [Co(C24H28N2O6)] n , crystallizes as infinite chains related to one another by inversion centers, giving a centrosymmetric coordination polymer. The Co(II) ion, situated on a twofold rotation axis, forms a complex with the crown-4 moiety of the 3,3'-[(1,7-dioxa-4,10-di-aza-cyclo-do-decane-4,10-di-yl)bis-(meth-ylene)]dibenzoate anion. The dis-torted octahedral coordination sphere of the Co(II) ion is completed by two carboxyl-ate O atoms from two bridging intra-chain ligands. Metallomacrocyclic rings of 16 atoms are present, with each ring containing two Co(II) ions and 14 atoms from the bridging ligands. These units repeat as infinite zigzag chains along [101].

Functionalization of multi-walled carbon nanotubes with bis(2,2':6',2"-terpyridine) ruthenium(II)-connected diblock polymer.

Multi-walled carbon nanotubes (MWCNTs) were functionalized with a bis(2,2':6',2"-terpyridine) ruthenium(ll)-connected diblock poly(N-isopropyacryamide) (RuTpyPNIPAM) by a simple methodology of covalent amidation. The composition and structure of the functionalized ruthenium multi-walled carbon nanotubes (RuMWCNTs) were characterized by thermogravimetric analysis, Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and scanning electron microscopy (SEM). These characterization methods confirm that after functionalization, ruthenium metallopolymer are interconnected or attached as aggregated structures on the surface of the carbon nanotubes.