Cyclic polyethers and their complexes with metal salts

Abstract

Thirty-three cyclic polyethers, derived from aromatic vicinal diols and containing from 9 to 60 atoms including 3 to 20 oxygen atoms in the ring, have been synthesized. Some of these have been prepared in good yields without the use of a high-dilution technique. Fifteen of the compounds have been catalytically hydrogenated to the corresponding saturated cyclic polyethers. Many of those containing five to ten oxygen atoms form stable complexes with some or all of the cations of: Li, Na, NH4, RNH3, K, Rb, Cs, Ag(I), Au(I), Ca, Sr, Ba, Cd, Hg(I), Hg(II), La(III), Tl(I), Ce(III), and Pb(I1). Many of these complexes can be isolated in the crystalline form depending on the anion. They appear to be salt-polyether complexes formed by ion-dipole interaction between the cation and the negatively charged oxygen atoms of the polyether ring. The stoichiometry of the complexes is one molecule of polyether per single ion regardless of the valence. Some of the polyethers, by complexing, solubilize inorganic compounds, such as potassium hydroxide and permanganate, in aromatic hydrocarbons. n a preparation of bis[2-(o-hydroxyphenoxy)ethyl]Pedersen 1 Cyclic Polyethers and Their Complexes with Metal Salts a This compound was previously prepared by Luttringhaus and Sichert-Modrow.6 This compound is not derived from an aromatic vicinal diol, but it is included as an example of an unsubstituted crown compound.

Poly(ethylene glycol) doubly and singly cationized by different alkali metal ions: Relative cation affinities and cation-dependent resolution in a quadrupole ion trap mass spectrometer

“…E xtensive solution and gas phase investigations of alkali metal ion cationization of small podands, which are linear or ring structures with repeating (-Carbon-Carbon-Heteroatom-) units, have lead to improved understandings of host-guest complexation [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Factors involved in the solution phase molecular recognition are solvation enthalpy and entropy for both species and the number of atoms from the ligand that are involved with the binding of the metal ion, plus any conformational change of the ligand between its unbound and bound forms [21].…”

Multidentate carborane-containing Lewis acids and their chemistry: mercuracarborands

“…Chloride ion sensing is based on a coextraction process, which is represented in Eq. (1). As the mercuracarborand ionophore (MC3) binds chloride ion, indicator protonation occurs causing a large change in membrane absorbance.…”

“…The recognition of supramolecular host Á/guest complexes as a discrete branch of chemistry evolved from the discovery of crown ethers and other cation-binding molecules [1]. Since that time, the search for electrophilic ''anti-crown'' species, which bind anions or electron-rich molecules, has been successfully pursued through a variety of independent research efforts.…”

Synthesis of N-pivot lariat ethers and their metal ion complexation behavior

“…Reaction of 2-methylnaphthalene (7) (2.00 g, 14.1 mmol) with N-bromosuccinimide (2.76 g, 14.1 mmol) by the procedure described above for the preparation of 3 produced 2.77 g (82% by 1 H NMR spectroscopy) of a brown solid that was a mixture of starting material, 2-bromomethylnaphthalene (9), and 2,2-dibromomethylnaphthalene. 1 Reaction of crude 9 (1.07 g) and aza-15-crown-5 (0.71 g, 3.24 mmol) by the procedure described above for the preparation of 4 gave 1.14 g (98%) of 11 as a brown oil. IR (neat): 1093 and 1124 (C-O) cm -1 .…”

“…IR (neat): 1093 and 1124 (C-O) cm -1 . 1 18,19 extractions were conducted by adding 0.50 mL of a 5.0 mM crown ether solution in CDCl 3 to 0.50 mL of an aqueous 5.0 mM metal picrate solution in a centrifuge tube. The mixture was agitated with a vortex mixer of 60 sec.…”