Electrospray ionisation mass spectrometry shows that arylstibonic acids, RSbO(3)H(2), give rise to oxo-bridged clusters derived from [H(8)(RSb)(12)O(28)] which act as inorganic crown ligands towards Na(+) cations; structure determination of one derivative revealed a cage-like anion [Na(2)H(9)(p-O(2)NC(6)H(4)Sb)(12)O(30).4H(2)O](-).

Glycoluril derivative--whose bulky Ph-C[triple bond]C- substituents prevent formation of H-bonded tapes--undergoes solvent dependent assembly in the crystal; a tetrameric molecular bowl is formed by R(24) H-bonding interactions from CH(2)Cl(2) whereas DMF results in H-bond dimerization followed by oligomerization via C-H...pi interactions.

The title compound, C(10)H(12)N(3)O(+)·Cl(-), is a derivative of o-phthaldehyde and methyl-thio-urea. The mol-ecules form dimers through intra- and inter-molecular N-H⋯O hydrogen bonds. The dimers are further linked into chains through one C-H⋯Cl and two N-H⋯Cl hydrogen bonds.

The title compound, C(12)H(21)NO(4), a γ-aminobutyric acid derivative, crystallizes with two mol-ecules in the asymmetric unit. The crystal structure is stabilized by inter-molecular N-H⋯O and O-H⋯O hydrogen bonds, forming a strand. An intramolecular N-H⋯O hydrogen bond is also observed.

Succinimidinium hydrogensulfate ([H-Suc]HSO4), as a new and stable derivative of succinimide, is easily prepared by the reaction of succinimide with neat sulfuric acid. This ionic liquid can be used as an efficient catalyst for the acetylation of alcohols, phenols, thiols and amines at room temperature under mild and solvent free conditions. All the products are separated and identified using d...

In the presence of magnesium and hexamethylphosphorictriamide, HMPT, trimethylchlorosilane, TMS-C1, reacts with cyanoepoxides to give related compounds. Ring cleavage at ? - position of cyanoepoxide, 1, followed by the addition of two trimethylsilyl groups leads to 2 then substitution of OSiMei by trimethylsilyl or H takes place to give ?, ? - bis (trimethylsilyl) nitrile or ? - trimethyls...

Fractional derivative can be defined as a fractional power of derivative. The commutator (i/h̄)[H, . ], which is used in the Heisenberg equation, is a derivation on a set of observables. A derivation is a map that satisfies the Leibnitz rule. In this paper, we consider a fractional derivative on a set of quantum observables as a fractional power of the commutator (i/h̄)[H, . ]. As a result, we ob...

The effect has been studied of Actinomycin D, Daunomycin (Da.), and Da. N acetyl derivative on mitotic activity and on the nucleic acid synthesis of in vitro HeLa cell cultures. The experiments were carried out by means of the radioautographic technique using stripping films. The relative uptake of thymidine-H(3) and uridine-H(3) was determined by means of the reduced silver grain count present...

R Upper-triangular matrix from QR decomposition v Direction unit vector: vj ; j ∈ [1, N ] Vinf Freestream velocity W Combined weight matrix Wb Derivative observation weight matrix: Wb i,j ≡ wi δi,j Wf Function observation weight matrix: Wf i,j ≡ wi δi,j x Vector of input quantities to f : xj ; j ∈ [1, N ] θ, φ Spherical polar coordinates {d} Vector of Taylor series derivatives: dk ; k ∈ [1, t] ...

By combining the explicit formula of the Shannon informational entropy ) , ( Y X H for two random variables X and Y , with the entropy )) ( ( X f H of ) (X f where (.) f is a real-valued differentiable function, we have shown that the density of the amount of information in Shannon sense involved in a non-random differentiable function is defined by the logarithm of the absolute value of its de...