Zeolite Pb,Br,H,Cs,Na-Y was prepared by the reaction of Cs 49 Na 22 -Y with PbBr 2 in a mixed organic solvent, and the structure of a single crystal of it was determined crystallographically. About 26% of its supercages hold a tetrahedral PbBr 42− ion at their centers. Each is surrounded by six Cs + ions, each of which bridges between the two Br − ions on each edge of the PbBr 4 2− tetrahedron. Each of these four Br − ions also bonds to a Na + ion near the center of a 6-ring. The result is a Na 4 Cs 6 PbBr 4 8+ quantum dot (QD) of symmetry 4̅ 3m (T d ). The supercage in this zeolite (Si/Al = 1.69) has an average charge of 8.9−, which nearly balances the 8+ charge of this QD. Water molecules in 12-rings bridge (Cs + −H 2 O−Cs + ) between QDs in adjacent supercages to form domains of tetrahedrally arranged QDs. Both these QDs and these domains are seen directly by electron microscopy. These QDs, when excited by UV radiation, luminesce sharply at 528 nm (green, FWHM = 17.8 nm). Pb,Br,H,Cs,Na-Y and its luminescence are entirely stable in the atmosphere; the bridging water molecules enhance the luminescence and provide that stability. Structure refinement was done in the space group Fd3̅ m (a = 24.889(4) Å) with the 886 unique reflections for which F o > 3σ(F o ) to the final error index R 1 = 0.077. Its composition was confirmed by energy dispersive X-ray analysis.

In this research work, an Fe(III)-IIP was prepared using methacrylic acid as monomer, divinylbenzene as cross-linker, azobisisobutyronitrile as initiator. The ion imprinted polymer was functionalized with Fe(III)8-hydroxy quinolone complex under thermal conditions by copolymerization with the monomer and the cross-linker. The prepared Fe(III)-ion imprinted polymer (IIP) and non-ion imprinted polymer (Non-IIP) were characterized with fourier transform-infrared spectroscopy, scanning electron microscopic analysis and thermal gravimetric analysis. The polymer showed a good stability to thermal analysis up to a temperature of 500 °C. The size of the polymer obtained was 1 µm, large enough to be filtered easily. At pH 2.5 more affinity was observed with ion imprinted polymer in comparison to non-ion imprinted polymer. For the kinetic study, the most linear and rhythmical relation were seen in pseudo second order. The maximum sorption capacity of Fe(III) ions on Fe(III)-IIP and non-IIP was 170 and 30.0 µmolg −1 , respectively. The relative selectivity factor (αr) values of Fe(III)/Fe(II), Fe(III)/Al(III) and Fe(III)/Cr(III) were 151.0, 84.6 and 91.9, respectively. The preconcentration factor was found to be 240. The developed method was successfully applied to the determination of trace Fe in the drinking water.

No abstract