An efficient, clean, simple and environmentally friendly one-pot synthesis of two small compound libraries in lemon juice as a solvent and catalyst is presented.

The most important results of extensive studies (syntheses, spectral, magnetic, voltammetric and structural characteristics and biological activity) of metal complexes with pyridoxal semi-, thiosemi- and isothiosemicarbazones are reviewed.

Pure and Pt-doped ZnO nanophase particles were synthesized by ultrasonic spray pyrolysis. The particles were obtained through the decomposition of zinc nitrate and with a newly developed Pt(IV) complex with 1,3-propylenediamine-N,N′-diacetate tetradentate class ligand (pdda). The complex was characterized by elemental analysis, electronic absorption and infrared spectroscopy. The form of the determined complex structure {trans-[Pt(pdda)Br2]·H2O} implies that Pt(IV) ion has a distorted octahedral coordination due to intramolecular N–H···Br interaction. The results of structural refinement (cell parameters, bond lengths, and ion occupancy) of ultrasonically derived pure and Pt-doped ZnO particles suggest either the formation of Zni interstitials or platinum ion incorporation into the ZnO lattice in octahedral interstitial positions, respectively. A well-crystallized hexagonal wurtzite structure of ZnO was pronounced in all investigated samples [JCPDS card 36-1415, Joint Committee on Powder Diffraction Standards, defined by International Centre for Diffraction Data (www.icdd.com)]. Phase determination also indicated the presence of a nitrate hydroxide hydrate phase (JCPDS card 24-1460), as a result of incomplete precursor decomposition and a spinel Zn2PtO4 phase (below 1.0 wt%) located in the boundary region for a Pt-doped ZnO sample. Based on x-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy analyses, it was shown that the different particle growingmorphologies, which were either spheroidally or pyramidally shaped, were influenced by the precursor chemistry, processing parameters and the presence of platinum ions. The composite internal particle structure revealed by transmission electron microscopy and selected area electron diffraction analyses, implied that the secondary particles represent an assembly of primary particles sized under 60 nm aroused during the processes of nucleation, growth and aggregation. Both hexagonal and spheroidal shape of primary particles was evident. The particle morphology, primarily particle size and the mechanism of Pt4+ ion introduction into the ZnO cell was discussed based on the structural refinement and selected area electron diffraction analysis.

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The work is concerned with the crystal and molecular structures of zinc(II) and mercury(II) complexes with 4-acetyl-3-amino-5-methyl--pyrazole (aamp) of the coordination formulae [Zn(NCS) 2 (aamp) 2 ] and (Haamp) 2 [Hg(SCN) 4 ]. The zinc(II) complex was obtained by the reaction of a warm methanolic solution of aamp with a mixture of zinc(II) nitrate and ammonium thiocyanate, whereas the mercury(II) complex was prepared by the reaction of a warm ethanolic solution of aamp and a warm, slightly acidified aqueous solution of [Hg(SCN) 4 ] 2-. Both complexes have a tetrahedral geometry, which in the case of zinc complex is formed by monodentate coordination of two aamp molecules and two isothiocyanate groups. The Zn(II) and Hg(II) atoms have significantly deformed coordination geometry. In both crystal structures the pyrazole derivative has a planar form, probably stabilized by an intramolecular N-H⋅⋅⋅O hydrogen bond. Apart from the X-ray structural analysis, the isolated complexes were characterized by elemental analysis, IR spectroscopy, conductometric measurements and thermal analysis. COMPLEXES OF Zn(II) AND Hg(II) WITH 4-ACETYL-3-AMINO-5-METHYLPYRAZOLE 1261 X-Ray experiments and crystal structure determinationSingle-crystal X-ray diffraction data for (Haamp) 2 [Hg(SCN) 4 ] were collected on an Enraf-Nonius CAD-4 diffractometer 18 using MoKα radiation (λ = 0.71069 Å) and ω/2θ scans in the 2θ range from 1.67 to 29.96°. The cell constants and an orientation matrix for data collection, obtained from 24 centered reflections in the range 12.10-16.82°, corresponded to a monoclinic cell, the dimensions of which are given in Table I. The data were corrected for Lorentz and polarization effects. 19 A Gaussian-type absorption correction 20-22 based on the crystal morphology was applied (T min = 0.217; T max = 0.354).