Two new Zn4L6 cages composed of diamine subcomponents containing either naphthalene diimide (NDI) or porphyrin moieties are described. Their structural differences allow these cages to exhibit distinct interactions with different chemical stimuli, yielding different supramolecular products. The electron-poor NDI subunits of the first cage were observed to thread through electron-rich aromatic c...

The co-crystal, C7H9N4O2 (+)·ClO4 (-)·C20H24O6·3.25H2O, consists of theobrominium (3,7-di-methyl-2,6-dioxo-1H-purin-9-ium) cations, perchlorate anions and dibenzo-18-crown-6 and water mol-ecules. The crown ether is in a bent conformation, in which the planes of the aromatic rings subtend an angle of 63.7 (1)°. Inter-molecular O-H⋯O hydrogen bonding between the water mol-ecules and the O atoms o...

We introduced an approach to the ion chromatographic determination of common mono- and divalent cations including hydrogen ion and demonstrated the ability of a C30 column dynamically coated first with dodecylsulfate and then with 18-crown-6 ether to separate the cations by ion-exchange mechanism. Using an ethylenediamine solution containing a small concentration of 18-crown-6 ether and lithium...

Three new electrodes were prepared by incorporating two different charge-transfer complexes and amino crown ether into plasticized PVC membranes. The electrodes showed Nernstian response to triiodide ion over the activity range from 1.0 x 10(-5) to 1.0 x 10(-1) mol x L(-1) with detection limits at approximately 1.0 x 10(-6) mol x L(-1). The resulting electrodes have fast response times (20-30 s...

In this work, the interaction of protonated amino acids with a chromene bearing a fused 18-crown-6 ether moiety was studied by UV-vis and NMR spectroscopy. Initial closed forms of the chromene form monotopic 1 : 1 complexes, the ammonium group being localized inside the crown ether cavity. UV-irradiation leads to transformation of the ring-closed species into the ring-opened form. Depending on ...

Two multidentate ditopic ligands L1 and L2 which contain both N-donor and crown ether units have been synthesised. The potentially octadentate ligand L1 forms a trinuclear heterometallic double helicate with Cu(I) and Zn(II) ([Zn2Cu(L1)2](5+)), whereas L2 forms a tetranuclear heterometallic double helicate with the same metal ions ([Zn2Cu2(L2)2](6+)). Both species have been characterised by (1)...

In the title compound, [Au(2)Ba(NCS)(4)(C(20)H(24)O(6))](n), the dithio--cyanato-aurate(I) anion adopts a dimeric structure with an Au⋯Au distance of 3.1109 (10) Å; both Au(I) atoms are also bonded to two S atoms. The Ba(II) ion adopts an irregular BaN(3)O(6) geometry, arising from the crown ether and three adjacent thio-cyanate N atoms; the extended structure of the complex can be described as...

the extraction of gadolinium (gd) from perchlorate and nitrate media in 1,2-dichloroethane(c2h4cl2), carbon tetrachloride (ccl4) and chloroform (chcl3) by mixtures of 2-thenoyltrifluoroacetone (htta) and a crown ether benzo-15-crown-5 (b15c5) is investigated.the composition of the extracted species is determined as gd(tta)3.nb15c5 (n=1 in nitratemedium and n=2 in perchlorate medium). the values...