A new dinuclear triphenyl-anti-mony(V) derivative with an oxide bridge, [Sb(2)(C(6)H(5))(6)(C(6)H(3)ClNO(2))(2)O], has been synthesized. Each Sb atom is five-coordianted by three C atoms and two O atoms in a distorted trigonal-bipyramidal geometry. Metal centers are bridged by a μ(2)-oxide functionality, and phenyl substituents on Sb atoms are in an staggered arrangement. The Sb-O-Sb bridge dis...

We have studied the structure of Sb-terminated GaAs(001) surfaces using reflection high energy electron diffraction, X-ray photoelectron spectroscopy, and scanning tunneling microscopy (STM). Clean, As-terminated (2×4) surfaces were prepared by molecular beam epitaxy and then exposed to Sb4 at 490°C, producing a (2×8)-reconstructed surface terminated with ~1 ML of Sb. Re-heating such a surface ...

Single crystals of trizirconium nickel hepta-anti-monide were synthesized from the constituent elements by arc-melting. The compound crystallizes in a unique structure type and belongs to the family of two-layer structures. All crystallographically unique atoms (3 × Zr, 1 × Ni and 7 × Sb) are located at sites with m symmetry. The structure contains 'Zr(2)Ni(2)Sb(5)' and 'Zr(4)Sb(9)' fragments a...

A preparação, o grau de dispersão, estabilidade térmica e a acidez de Lewis e de Brφnsted do óxido de antimônio (V) adsorvido sobre SiO 2 /ZrO 2 , preparado previamente pelo processo sol-gel, são descritas neste trabalho. Amostras de SiO 2 /ZrO 2 /Sb 2 O 5 de composições (% em massa): (a) Zr= 8,1 e Sb= 6,3; (b) Zr= 11,4 e Sb= 11,4, foram preparadas. As imagens de microscopia eletrônica de varre...

It is shown that for 2 ≤ t ≤ n− 3, a strict t-SB(n, n− 1) design does not exist, but for n ≥ 3, a non-strict 2-SB(n, n−1) design exists. The concept of large sets for Steiner triple systems is extended to SB designs and examples of a large sets for SB designs are given.