Ringwoodite [(Mg,Fe)2SiO4 spinel] has been considered as one of the most important host minerals of water in the Earth’s deep mantle. Its extensive hydration was observed in high-pressure synthesis experiments and also by its natural occurrence. Water can dissolve into ringwoodite as structurally bound hydrogen cations by substituting other cations, although the hydrogen site and its occupancy ...

In the early stages of liver Carcinogenesis induced by 4-dimethylaminoazobenzene the subcellular pattern of calcium, magnesium, sodium, and potassium is sharply altered. Divalent cations decrease in the nuclear and mitochondrial fractions and in crease in the residual fraction. In the case of mitochondria, however, cations decrease proportionally to the amount of proteins and nucleoproteins in ...

Preincubation of the group I intron Ca.LSU from Candida albicans at 37 degrees C in the absence of divalent cations results in partial folding of this intron. This is indicated by increased resistance to T1 ribonuclease cleavage of many G residues in most local helices, including P4-P6, as well as the non-local helix P7, where the G binding site is located. These changes correlate with increase...

Adsorption of 1-propanethiol on Co and Cd modified, synthetic (3A, 4A and 13X) zeolites were studied by FTIR (Fourier Transform Infrared) spectroscopy and SEM-EDX (Scanning Electron Microscope-Energy Dispersive X-Ray) graphics. Amount of metal cations on mentioned zeolites was measured by AAS (Atomic Absorption Spectrometer). Based on divalent cations of zeolites, it was assumed that cations ma...

The crystal structures of the title salts, (C7H11N2)2[Mn(NCS)4] (1) and (C7H11N2)3[Mn(NCS)5] (2), consist of manganese(II) cations that are tetra-hedrally (1) or trigonal-bipyramidally (2) coordinated to four or five terminal N-bonded thio-cyanate ligands, respectively, into discrete anionic complexes. The negative charge is compensated by two (1) or three (2) 4-(di-methyl-amino)-pyridinium cat...

Two-dimensional triple-quantum (2D-3Q) 23Na MAS NMR spectroscopy has been applied for the investigation of sodium cations in dehydrated zeolites NaY, NaEMT, NaZSM-5 and NaMOR. The experiments have shown that the new 2D-3Q technique allows the determination of the isotropic chemical shifts and quadrupolar couplings of sodium cations with SOQE (second-order quadrupolar effect) parameters of up to...

The ferrocene-benzobisimidazole derivative shows high affinity for Pb(2+) and Zn(2+) metal cations over a range of other metal cations examined. In the presence of Pb(2+) the emission spectrum is red-shifted by 13 nm with an important chelation-enhanced fluorescence effect (CHEF) CHEF = 55. The presence of Zn(2+) cations also induced a perturbation of the emission spectrum although to a lesser ...

Covalent grafting of chromotropic acid (CA) moiety to a glassy carbon electrode was performed by electrochemical reduction of the corresponding diazonium cation generated in situ. Grafted electrodes were subjected to the electrochemical detection of multivalent cations using Fe(CN)(6)(3-/4-) as an electrochemical probe molecule. In the absence of metal cations, redox reaction of the anionic p...

In the title compound, Na(3)(C(6)H(15)N(5)O)(2)[Al(OH)(6)Mo(6)O(18)](2)Cl·20H(2)O, the [Al(OH)(6)Mo(6)O(18)](3-) polyoxo-anion has a B-type Anderson structure exhibiting approximate D(3d) symmetry. There are two types of sodium cations: the Na(+) cations of type I have a distorted octa-hedral coordination geometry formed by six O atoms and are statistically distributed over two positions with e...

Metal oxides with a tunnelled structure are attractive as charge storage materials for rechargeable batteries and supercapacitors, since the tunnels enable fast reversible insertion/extraction of charge carriers (for example, lithium ions). Common synthesis methods can introduce large cations such as potassium, barium and ammonium ions into the tunnels, but how these cations affect charge stora...