In Situ Doping Strategy for the Preparation of Conjugated Triazine Frameworks Displaying Efficient CO2 Capture Performance.

An in situ doping strategy has been developed for the generation of a novel family of hexaazatriphenylene-based conjugated triazine frameworks (CTFs) for efficient CO2 capture. The resulting task-specific materials exhibit an exceptionally high CO2 uptake capacity (up to 4.8 mmol g(-1) at 297 K and 1 bar). The synergistic effects of ultrananoporosity and rich N/O codoped CO2-philic sites bestow the framework with the highest CO2 adsorption capacity among known porous organic polymers (POPs). This innovative approach not only enables superior CO2 separation performance but also provides tunable control of surface features on POPs, thereby affording control over bulk material properties. We anticipate this novel strategy will facilitate new possibilities for the rational design and synthesis of nanoporous materials for carbon capture.

1,10-Phenanthroline and non-symmetrical 1,3,5-triazine dipicolinamide-based ligands for group actinide extraction.

The synthesis and evaluation of new extractants for spent nuclear fuel reprocessing are described. New bitopic ligands constituted of phenanthroline and 1,3,5-triazine cores functionalized by picolinamide groups were designed. Synthetic routes were investigated and optimized to obtain twelve new polyaza-heterocyclic ligands. In particular, an efficient and versatile methodology was developed to access non-symmetric 2-substituted-4,6-di(6-picolin-2-yl)-1,3,5-triazines from the 1,3,5-triazapentadiene precursor in the presence of anhydride reagents. Extraction studies showed the ability of both ligand series to extract and separate actinides selectively at different oxidation states (U(VI), Np(V,VI), Am(III), Cm(III), and Pu(IV)) from an acidic solution (3 M HNO3). Phenanthroline-based ligands show the most promising efficiency for use in the group actinide extraction (GANEX) process due to a higher number of donor nitrogen atoms and a suitable pre-organization of the dipicolinamide-1,10-phenanthroline architecture.

Selective separation of americium from europium using 2,9-bis(triazine)-1,10-phenanthrolines in ionic liquids: a new twist on an old story.

Bis-triazine phenanthrolines have shown great promise for f-block metal separations, attributable to their highly preorganized structure, nitrogen donors, and more enhanced covalent bonding with actinides over lanthanides. However, their limited solubility in traditional solvents remains a technological bottleneck. Herein we report our recent work using a simple 2,9-bis(triazine)-1,10-phenanthroline (Me-BTPhen) dissolved in an ionic liquid (IL), demonstrating the efficacy of IL extraction systems for the selective separation of americium from europium, achieving separation factors in excess of 7500 and selectively removing up to 99% of the americium. Characterization of the coordination environment was performed using a combination of X-ray absorption fine structure spectroscopy (XAFS) and density functional theory (DFT) calculations.

Selective separation of trivalent f-ions using 1,10-phenanthroline-2,9-dicarboxamide ligands in ionic liquids.

1,10-Phenanthroline-2,9-dicarboxamide complexants decorated with alkyl chains and imidazolium cations have been studied for extraction of trivalent f-ions into imidazolium ionic liquids. The dicationic complexants are shown to extract Am over Eu with separation factors >50 and high extraction efficiencies. The different size selectivities for lanthanide ions were observed for these two types of complexants, highlighting the importance of the positive charge in controlling both extraction efficiencies and extraction selectivities.

Preparation of carboxylate derivatives of terpyridine via the furan pathway.

This protocol describes a practical procedure for the preparation of terpyridine carboxy derivatives, which have numerous applications, including being photoactive components of functional materials, and which can be used in medicinal chemistry or in catalysis. This protocol relies on the permanganate-mediated oxidation of a furan ring on the polypyridine system. The procedure involves three stages. First, a furan-functionalized terpyridine is synthesized from furfuraldehyde and a 2-acetylpyridine derivative. Second, the furan ring is oxidized thus providing a carboxylic acid. Finally, esters are prepared by reaction of the acids in refluxing alcohols. The procedure is simple, uses a reagent available from renewable resources (furfural) and avoids the use of noxious reagents or solvents, thus making it more environmentally friendly when compared with previously described methods. The whole protocol can be conducted in ∼10 d, including isolation and drying of intermediates and products.