In-situ X-ray diffraction activation study on an Fe/TiO2 pre-catalyst.

This study focuses on the use of in situ powder X-ray diffraction (PXRD) and quantitative phase analysis using the Rietveld method to monitor the structural properties of a titania-supported iron (10% Fe/TiO2) pre-catalyst during calcination (oxidation) and activation (reduction) in the temperature range 25-900°C. The TiO2 oxidation study revealed an increase in anatase particle size before the anatase to rutile phase transformation, lending credibility to the bridging mechanism proposed by Kim et al. [(2007), Mater.

Poly[1,4-bis-(ammonio-meth-yl)cyclo-hexane [di-μ-iodido-diiodido-plumbate(II)]].

The title compound, {(C(8)H(20)N(2))[PbI(4)]}(n), is an inorganic-organic hybrid. The structure is composed of alternate layers of two-dimensional corner-sharing PbI(6) octa-hedra ( symmetry) and 1,4-bis-(ammonio-meth-yl)cyclo-hexane cations ( symmetry) extending parallel to the bc plane. The cations inter-act with the inorganic layer via N-H⋯I hydrogen bonding in the right-angled halogen sub-type of the terminal halide hydrogen-bonding motif.

Poly[1,4-bis-(ammonio-meth-yl)cyclo-hexane [di-μ-chlorido-dichloridoplumbate(II)]].

The title compound, {(C(8)H(20)N(2))[PbCl(4)]}(n), crystallizes as an layered inorganic-organic hybrid perovskite-type structure. Corner-sharing PbCl(6) octa-hedra extend parallel to the ac plane. Adjacent layers are staggered relative to one another, with diammonium cations separating these layers.

Poly[1,4-bis-(ammonio-meth-yl)cyclo-hexane [di-μ-bromido-dibromido-plumbate(II)]].

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 right-angled halogen sub-type of the terminal halide hydrogen-bonding motif.