The various association constants, bnm and Knm, of NaCl and NaClO4 with [12]crown-4, [15]crown-5, [18]crown-6, benzo[15]crown-5, benzo[12]crown-4, dibenzo[18]crown-6 and dinaphtho[18]crown-6 have been estimated in a mixture of dioxane/water (80/20) using a sodium ion selective electrode (ISE). The constants have been estimated using 1=ðKnm1⁄2Lo n1m21Þ5 ð1 2 nP 0Þn ð1 2 mP 0Þm=P 0; where P 0, th...

Abstract The new compounds with the sum formulae [Cs([18]crown‐6)] 2 [Zn(C H) 4 ] ⋅ 8NH 3 , Rb [Rb([18]crown‐6)(NH )][Cd(C {[18]crown‐6 2NH } NH and [Cs([2.2.2]crypt)][In(C 6 H 5 ) (C H)] were synthesized in liquid ammonia. anionic units show tetrahedrally coordinated central atoms four hydrogenacetylide ligands or one C − three ligands. Solid state starting materials for these either A ( =Rb, ...

On heating the hydrated complexes 18-Crown[6].M[H(2)PO(4)].xH(2)O (x= 2 for M = K, Rb; x= 1.5 for M = Cs), quantitatively prepared by mechanical mixing of crystalline 18-Crown[6] and M[H(2)PO(4)], to ca. 60 degrees C, water loss takes place, accompanied by the extrusion of the crown ether from the crystalline complex and followed by reconstruction of the inorganic phase M[H(2)PO(4)](M = K, Rb, ...

Ab initio QMCF-MD simulations of aqueous 18-crown-6 (18C6) and strontium(II)-18-crown-6 (18C6-Sr) were performed to gather insight into their hydration properties. Strongly different characteristics were found for the two solutes in terms of structure and dynamics such as H-bonding. They, however, have in common that their backbone shows high flexibility in aqueous medium, adopting structures s...

BACKGROUND Dibenzo-18-crown-6 (DB18C6) exhibits the binding selectivity for alkali metal cations in solution phase. In this study, we investigate the main forces that determine the binding selectivity of DB18C6 for the metal cations in aqueous solution using the density functional theory (DFT) and the conductor-like polarizable continuum model (CPCM). RESULTS The bond dissociation free energi...

The enthalpies of solution of the cyclic ethers 1,4-dioxane, 12-crown-4 and 18-crown-6 in mixtures of ethanol and water have been measured within the whole mole fraction range at T = 298.15 K. The enthalpy of solvation has been calculated. In pure ethanol and pure water, the solvation enthalpy of the investigated cyclic ethers depends linearity on the number of -CH2CH2- groups in the cyclic eth...

The compound [A([18]crown-6]2[Pt(CO)3] ⋅ 10 NH3 (A=K, Rb, [18]crown- 6=1,4,7,10,13,16-Hexaoxacyclooctadecane) containing the anion [Pt(CO)3]2− was unexpected result of a reaction between K6Rb6Ge17, Pt(CO)2(PPh3)2, [18]crown-6 and [2.2.2]-crypt. This represents first example mononuclear carbonyl platinate expands list known group metallates. central has trigonal planar shape with an approximate ...

The title compound, C(18)H(26)N(2)O(5)P(2), was obtained accidently from the reaction between N,N-dimethyl-phospho-ramido-chloridic acid 4-methyl phenyl ester, NaNO(2) and 18-crown-6 in acetonitrile under reflux conditions. The asymmetric unit contains one half-mol-ecule, the complete mol-ecule being generated by crystallographic twofold symmetry, with the bridging O atom lying on the rotation ...

Sandwich-type hydrogen-bonded supramolecular dications (DAAz(2+))([18]crown-6)(2) and (DAAz(2+))(dicyclohexane[18]crown-6)(2) (DAAz(2+) = 4,4'-(phenylazophenyl)diammonium) were introduced into [Ni(dmit)(2)](-) anions via a diffusion method to form novel single crystals (DAAz(2+))([18]crown-6)(2)[Ni(dmit)(2)](2) (1) and (DAAz(2+))(dicyclohexane[18]crown-6)(2)[Ni(dmit)(2)](2) (2), respectively, w...