C-Donor lariat ether ‘scorpionates’

Cooperative anion binding and electrochemical sensing by modular podands

“…The weakly coordinating nature of the PF 6 Ϫ anion is highlighted by the structure of the acetone solvate 3c⅐2Me 2 CO. In this case the NH and adjacent CH groups interact with the oxygen atom of the included acetone guest, whereas the PF 6 Ϫ anions are held solely by a series of weak CH⅐⅐⅐F hydrogen bonds (34)(35)(36)(37)(38)(39)(40). In both cases it is evident that each PF 6 Ϫ is bound weakly by a single arm in a nonchelating fashion, as expected.…”

Organometallic cavitands: Cation–π interactions and anion binding via π-metallation

“…This is illustrated by the short Ag-C contacts with distances of Ag(2)-C(32) 2.58Å and Ag(2)-C(31) 2.61Å. These longer-arm lariat ethers also bind potassium cations in the solid state [48,[55][56][57][58] albeit with much longer K. . .C distances but there is less evidence for K + -interactions in solution, unlike the Ag + analogues.…”

“…. interaction depending on the length of the side arm [55]. The structure of silver-coordinated N-allylaza-15-crown-5 (17) was obtained (Fig.…”

“…(a) coordination polymer formed by the silver(I) complex of N-allylaza-15-crown-5 (17) compared to (b) the discrete 'scorpionate' structure of the silver(I) complex of (N-3-butenylaza-18-crown-6 (18)[55].…”

The Fluorescence Properties of Free and Cation-complexed Lariat Ethers having Sidearms Terminated by a Benzene Ring

“…In addition, when the sidechains of N,N 0 -bis(propargyl)-4,13-diaza-18-crown-6 were elongated from 2-propynyl to 3-butynyl, crystal structure data showed that the triple bond served as a pi-donor for the macroringcomplexed cation [14]. Based on the successful solution NMR study noted above [12], and other recent work [15], we considered fluorescence as a method to detect cation-pi participation in solution.…”