The 1, 3-bis(trimethyl silyl)ether of p-tert-butyl calix[4]arene, Rt-Bu)Ca1ixTMS21112, has beensynthesized and used as a dianionic ligand for "Sn". The complex of [(t-Bu)Ca1ixTMS2]Snexhibits exo and endo isomerism. The structural properties of [(Rp)Ca1ixTMS2]Sn, (Rpara= H,CH3, t-Bu) and the inter conversion of exoendo isomers were investigated by using of SCF-MOPM3 method.

in this research na-y was synthesized by hydrothermal method and used as support for preparation of sn/pt/na-y catalysts using two different tin precursors, bu3sn(cl) and sncl2.2h2o, by sequential impregnation, in which the pt  was deposited first and in the next step sn was deposited. the catalysts were characterized by h2 chemisorption, transmission electron microscopy (tem), scanning electro...

In this paper, three-dimensional elasto-plastic finite element analysis was performed on flexible pavements under vertical repeated traffic loads to evaluate their shakedown behavior. Six different pavements with different structural number (SN) were modeled and subjected to a wide range of cyclic vehicle loads. Shakedown limits were obtained considering both failure and serviceability restrain...

The title complex, [Sn(IV)(C(44)H(28)N(4))(CNO)(OH)], exhibits substitutional disorder of the OH(-) and OCN(-) axial ligands. Thus, the cyanato-O ligand and the hydroxyl group bonded to the central Sn(IV) atom share statistically the axial position. The Sn(IV) ion is hexa-coordinated by the four N atoms of the pyrrole rings of the tetra-phenyl-porphyrin (TPP) and the O atoms of the two disorder...

Abstract. We say that permutations π1, . . . , πr ∈ Sn invariably generate Sn if, no matter how one chooses conjugates π 1 , . . . , π r of these permutations, π 1 , . . . , π r generate Sn. We show that if π1, π2, π3 are chosen randomly from Sn then, with probability tending to 1 as n → ∞, they do not invariably generate Sn. By contrast it was shown recently by Pemantle, Peres and Rivin that f...

Proof. Let A = k[s1, . . . , sn] where s1, . . . , sn ∈ A. We assume that A is not integral over k, in which case at least one of the si is not algebraic over k. If the set {s1, . . . , sn} is algebraically independent, then we are done. Otherwise assume that sn is algebraic over k[s1, . . . , sn−1] (by relabeling if necessary). Let f(x1, . . . , xn) be a nonzero polynomial with f(s1, . . . , s...

In [2], Dixon considered the following question: " Suppose two permutations are chosen at random from the symmetric group Sn of degree n. What is the probability that they will generate Sn? " Actually, Netto conjectured last century that almost all pairs of elements from Sn will generate Sn or An. Dixon showed that this is true in the following sense: The proportion of ordered pairs (x, y) (x, ...

The Sn(IV) atom in the title compound, [Sn(C(6)H(5))(2)Cl(2)(C(13)H(12)OS)], displays a distorted C(2)Cl(2)O trigonal-bipyramidal coordination environment, with a mean Sn-C distance of 2.121 (9) Å and with Sn-O = 2.331 (2) Å. The Sn(IV) atom is displaced by 0.169 (2) Å from the equatorial C(2)Cl plane towards the direction of the second axially bonded Cl atom.