Time-resolved liquid jet photoelectron spectroscopy was used to explore the excited state dynamics at the liquid water surface in the presence of alkali cations. The data were evaluated with the help of ab initio calculations on alkali-water clusters and an extension of these results on the basis of the dielectric continuum model: 160 nm, sub-20 fs vacuum ultraviolet pulses excite water molecul...

A new polyvinyl choloride (PVC) membrane sensor for cerium (III) was prepared based on 4,13-didecyl-1,7,10,16-tetraoxa-4,13-diazacyclooctadecane (kryptofix22DD) as an ionophore. The sensor exhibites a linear concentration range of 1.0×10-6to 1.0×10-1M, with a Nernstian slope of 18.0±1.0 mV/decade, and a detection limit of 9.7×10-7M. It has a fast response time (5 s) and can be used for two mont...

A new series of noncyclic ionophores containing two to four furan units (Ia to IIIb) i.e. 1,1-difurylethane (Ia), 2,5-bis(methylfurfuryl)furan (IIa) and 1,1’ ethyledenebis[5-(methylfurfuryl)furan] (IIIa), 2,2-difurylpropane (Ib), 2,5-bis (dimethylfurfuryl)furan(IIb), 2,2’-isopropylidenebis[5-(dimethylfurfuryl)furan] (IIIb) have been synthesized by the condensation of furan with acetaldehyde and...

The synthesis and cation-binding properties of a series of Calixarene derivatives possessing alkyl chain groups, ester groups and crown ether rings have been investigated. The syntheses of Calix[4]arene crown ethers and Calix[6]arene derivatives possessing alkyl chain, ester group and crown ether ring have been described. In order to evaluate their monovalent cation binding abilities, solvent e...

Chelate complexes of 1,2-dimesitoylbenzene radical anion with alkali metal cations exhibit in aprotic solution extremely iarge ESR/ENDOR metal coupling constants. For rationaliza­ tion, structures of both the neutral molecule (H 3C)3H2C6C O C 6H4 C O C 6H2(CH3)3, in which the two carbonyl groups are twisted out of the benzene ring plane by dihedral angles of ± 37°, and a sodium contact ion quad...

The DO1(18c6)fi (MwLi. Na. K and I 8c6=18-crown-6) complexes have been chosen as the model systems toinvestigate the nature of chemical bonds between alkali metal cations and large mffitidentaie orgmnic ligands.The B3LYP/6-3I+G(d,p) level of calculation has been used for obtaining equilibrium geernetnes and p(r)functions (electron density distributions). By the aid of fundamental physical theor...

The influx of Na(+), K(+), Rb(+), and Cs(+) into frog sartorius muscle has been followed. The results show that a maximum rate is found for K(+), while Na(+) and Cs(+) penetrate much more slowly. Similar measurements with Ca(++), Ba(++), and Ra(++) show that Ba(++) penetrates at a rate somewhat greater than that of either Ca(++) or Ra(++). All these divalent cations, however, penetrate at rates...

a new polyvinyl choloride (pvc) membrane sensor for cerium (iii) was prepared based on 4,13-didecyl-1,7,10,16-tetraoxa-4,13-diazacyclooctadecane (kryptofix22dd) as an ionophore. the sensor exhibites a linear concentration range of 1.0×10-6to 1.0×10-1m, with a nernstian slope of 18.0±1.0 mv/decade, and a detection limit of 9.7×10-7m. it has a fast response time (5 s) and can be used for two mont...

Potassium chromium aluminium diarsenate, KCr1/4Al3/4As2O7, was prepared by solid-state reaction. The structure consists of (Cr1/4/Al3/4)O6 octa-hedra and As2O7 diarsenate groups sharing corners to build up a three-dimensional anionic framework. The potassium cations are located in wide channels running along the c-axis direction. The crystal structure is isostructural with the triclinic AIMIIIX...

— CdF2 samples provided with different kinds of electrodes and insulations are investigated. It is found that, due to an electron injection which cannot be avoided, metal particles are formed below the surface which act as a kind of « reversible dendritic electrode »; that the cations are discharged by segregation there and/or at the external cathode; that the two known space-charge formation T...