The asymmetric unit of the title organic-inorganic molecular salt, C6H18N2 (2+)·SiF6 (2-), consists of one anion and one cation together with half of each of two cations and two anions located on inversion centres. The SiF6 (2-) octa-hedral anions are arranged to form sheets parallel to (011), which are linked into a three-dimensional network by the organic cations through N-H⋯F hydrogen bonds.

In the title salt, (C12H20N2)[CuCl4], the Cu(II) atom occupies a general position in a flattened tetra-hedral environment by Cl ligands, characterized by Cl-Cu-Cl angles of 134.04 (3) and 137.18 (4)°. The six-membered piperazinediium ring adopts a chair conformation. The organic cation and inorganic anion inter-act through N-H⋯Cl and C-H⋯Cl hydrogen bonds, forming a three-dimensional network.

Certain bivalent cations, particularly Mg(++) and Mn(++), can be absorbed by yeast cells, provided that glucose is available, and that phosphate is also absorbed. The cation absorption is stimulated by potassium in low concentrations, but inhibited by higher concentrations. From the time course studies, it is apparent that the absorption rather than the presence of phosphate and the potassium i...

In the crystal of the title polymeric compound, [Cu(2)(SO(4))(2)(C(5)H(5)N(3)O)(2)(H(2)O)(4)](n), two independent Cu(II) atoms are located on individual inversion centers. One Cu(II) atom is coordinated by four water mol-ecules and two pyrazine-2-carboxamide ligands in a distorted O(4)N(2) octa-hedral geometry; the other is N,O-chelated by two pyrazine-2-carboxamide ligands and further coordina...

The asymmetric unit of the organic-inorganic hybrid salt, 2C(9)H(14)N(+)·C(10)H(6)O(6)S(2) (2-)·2H(2)O, consists of one dimeth-yl(4-methyl-phen-yl)ammonium cation, one half of a naphthalene-1,5-disulfonate anion lying on a crystallographic centre of inversion, and one water mol-ecule. In the crystal, O-H⋯O(S) and N-H⋯OH(2) hydrogen bonds link the cations and anions forming ring motifs.

The title compound, {(C(8)H(20)N(2))[PbBr(4)]}(n), crystallizes as an inorganic-organic hybrid with alternating layers of diammonium cations and two-dimensional corner-sharing PbBr(6) octa-hedra extending parallel to the bc plane, which are eclipsed relative to one another. Both PbBr(6) octa-hedra and the organic cation exhibit symmetry. The cations inter-act via N-H⋯Br hydrogen bonding in the ...

Extensive minimization and dynamics computational studies of the hammerhead structural domain of the virusoid of lucerne transient streak virus have been carried out. The following observations at the self-cleavage position are derived from the resulting three-dimensional structure: (i) the cytosine base is at the surface and does not interact with another base (it is free to move), and (ii) th...

Iron(iii) sulfate, a rhombohedral NASICON compound, has been demonstrated as a sodium intercalation host. This cost-effective material is attractive, as it can be slurry processed in bulk with ball-milling, while utilizing the iron 2(+)/3(+) redox couple, offering stable 3.2 V performance for over 400 cycles.

Although RNA interactions with K+ and Mg2+ have been studied extensively, much less is known about the third most abundant cation in bacterial cells, putrescine2+, and how RNA folding might be influenced by the three ions in combination. In a new approach, we have observed the competition between Mg2+ and putrescine2+ (in a background of K+) with native, partially unfolded and highly extended c...