Cryptand ligands for selective lithium coordination

Calixarene‐Based Picolinamide Extractants for Selective An/Ln Separation from Radioactive Waste

“…It is well-known, in fact, that nitrogen ligands have a high affinity for lithium ion. [35] On passing from an LiNO 3 concentration of 1 m to 2 m the common anion effect operates but increases the D M values only slightly. Table 6).…”

Synthesis, characterization, and metal extraction studies of a new macrobicyclic ligand

“…The structures of the new compounds were characterized by a combination of elemental analysis and 1 H NMR, 13 C NMR, IR, and MS spectral data. The reaction of 27,28-dibromo-6,7,9,10,12,13,16,17,23,24,31,32-dodecahydro-5H,15H-tribenzo[b,h,w] [1,4,7,13,16,19,25,10,22]dioxapentathiadiazacycloheptacosine 1 with 3 equivalents of chloroacetic anhydride in dichloromethane at 0-5 • C under argon atmosphere afforded 1,1'- (27,28-dibromo-6,7,9,10,12,13,15,16,23,24,31,32-dodecahydrotribenzo[b,h,w] [1,4,7,13,16,19,25,10,22]dioxapentathiadiazacycloheptacosine-5,17-diyl)bis(2-chloroethanone) 2 in 90% yield. A free -NH stretching vibration at 3346 cm −1 in the IR spectrum of precursor compound 1 24 disappeared after the introduction of chloroacetic anhydride as amide function.…”

“…4 Because of their unique architecture, stabilities, and functions, macrobicyclic compounds are used in a wide variety of areas, for instance, in ion size recognition, 5 separation of cations, 6 transport process in biological systems, and in industrial, technological, and other applications. 7 There is strong demand to extract and separate heavy metals and precious metals from aqueous solution due to their toxicity 8 and commercial importance. 9 A goal of research on macrocyclic chemistry is to achieve selective complexation of heavy metals and precious metals with macrocycles and macrobicycles.…”

Oxovanadium(IV) Complexes with Nitrogen Donors: Synthesis, Characterisation, and Biological Activities

“…Macrocyclic nitrogen donor ligands [1] have received special attention because of their versatile coordination modes [2] and for their biological activities, that is, toxicity against bacterial [3] and fungal growth, anticancerous [4], and other biochemical properties [5]. Such ligands, for example, porphyrins, salicylates, and sulphosalicylates, are known to play a very important and vital role in the stability of the metal complexes with the factor of having specific cavity size, stereochemical rigidity, flexibility, and ability to coordinate with metal atom [6]. SA/SSA ligands and their complexes are widespread in nature and of considerable relevance in medicinal chemistry [7] and also in industries [8,9] (e.g., in the preparation of heterometallic precursors to oxide materials).…”