Structural aspects of metal–amide complexes

N-Alkyl pyrrolidone ether podands as versatile alkali metal ion chelants

“…Reaction of compound 1 with NaPF 6 in acetonitrile followed by solvent evaporation after brief sonication to aid dissolution results in the isolation of three crystalline solids; two discrete complexes 10 of formulae [Na (1) 2 ]PF 6 (3) and [Na 3 (H 2 O) 2 (-1) 2 ](PF 6 ) 3 (4), and a coordination polymer {[Na 3 (µ 3 -1) 2 (µ 2 -1) 2 ](PF 6 ) 3 } n (5), with metal:ligand stoichiometry 1:2, 3:2 and 3:4, respectively. The product obtained is dependent primarily on the ratio of metal salt and ligand added and highlights the extremely versatile 15 coordination behaviour of ligand 1.…”

“…Each of these two Na + cations is 110 situated in an environment closely related to the coordination geometry of the sandwiched Na(1) + ion in 4 and hence also interact with the ether donors with distances of 2.35 -2.50 Å, comparable to 3 and 4. The remaining Na + cation, Na (1), is bound to a total of four pyrrolidone oxygen atoms that are part of the sandwiched core; two doubly bridging and two triply bridging. This 'peripheral' sodium ion also binds to two further bis(pyrrolidone) ether ligands solely via the pyrrolidone oxygen atoms (the ether groups are uncoordinated, highlighting the better 5 donor properties of the former).…”

“…1 Incorporation of the amide functionality within a cyclic 25 lactam offers increased control over the amide bond polarity. Pyrrolidone and caprolactam derivatives in particular are common, commercially important functional groups because of the high polarity and hence high hydrophilicity and surface affinity of their amide carbonyl groups.…”

Solvent Extraction Behavior of Silver with the Secondary Phenylamide Derivative of the Trident Molecule

“…That is, silver was loaded on the extractant without any peak shift. In our previous work, when host molecules such as calixarene derivatives were structurally fixed by silver loading, peak shifts of the aryl protons were observed due to the shielding effect of the for π-electrons of the benzene rings [17,18,28]. Silver was extracted inside the extractant molecule and sufficiently surrounded by functional groups.…”

“…The amide compounds have three advantages in that they can be completely incinerated at the end of the process as they only contain atoms of hydrogen, carbon, nitrogen and oxygen [27], they are poorly soluble in the aqueous phase because of the neutral ligand and, moreover, they have a strong coordination ability throught the high charge density carbonyl oxygen atom [28,29].…”