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Synthesis of zeolites from fly ash is an ecologically justified process aimed at the transformation of energy sector waste – fly ash into microcrystalline zeolites of broad possible application field. In this study, the synthesis of zeolites from fly ash by using a modified two-step synthesis was presented. The aim of such a planned experiment was to use the waste solutions from previous synthesis, in such a way that minimalization of negative influence of post-synthesis wastes on environment was possible. Received materials were tested for its sulfur dioxide sorption capacity, indicating its future possible application to capture SO2 from exhaust gases.

Two simple pathways using metallic copper or copper salts are proposed for the synthesis of hybrid compounds under mild conditions. A variety of Strandberg-and mixedmetal Keggin-based products, namely, (NH 4 ) 5n {[Cu(en) 2 ]-[PMo 8 V 4 O 40 ]} n ·9nH 2 O (1), (NH 4 ) 4n {[Cu(en)(H 2 O)][P 2 Mo 5 O 23 ]} n · 3.5nH 2 O (2), (NH 4 ) 7 [PMo 8 V 4 O 40 ]·17H 2 O (3) and (NH 4 ) 2n -{[Cu(en) 2 ][Cu(en)(H 2 O)][P 2 Mo 5 O 23 ]} n ·3nH 2 O (4), were isolated upon the variation of the composition of the reaction system. A rare four-substituted [PMo 8 V 4 O 40 ] 7-Keggin anion was obtained. The influence of the vanadium source [V 2 O 5 , NH 4 VO 3 or [a]

Oxidovanadium(IV) complexes with substituted chiral tetradentate dianionic N,N'-bis-o-hydroxybenzylidene-1,2-propylenediamines were synthesized and their physicochemical properties were characterized using single crystal X-ray diffraction, elemental analysis, ATR FTIR, UV-VIS and EPR spectroscopy, cyclic voltammetry, spectroelectrochemistry and preliminary in vitro protein-tyrosine phosphatase inhibition activity studies. Different 5-substituents in the salicylaldehyde (condensed with 1,2-diaminopropane; 2 : 1) were tested, namely 5-Br (complex 1), 5-Cl (2), 5-NO2 (3) and 5-OCH3 (4). The crystal structures of 1 and 2 show square pyramidal coordination of vanadium and parallel arrangement of monomeric exo isomers in supramolecular dimers. The halogen-halogen interaction of substituents in 5,5'-positions leads to weakening of axial interaction between phenolate O and V in 2, compared to 1. The Br atom takes part in halogen bonding with a vanadyl group in 1. Complex 3 has a linear polymeric structure with a V-O-V asymmetric bridge motif (IR absorption band at 873 cm(-1), separated d-d bands and broad EPR band structure in frozen solution pointing to oligomeric nature) while 4 is monomeric (V=O stretching at 976 cm(-1), broad d-d band structure). Redox potentials of the V(4+)/V(5+) couple lie in the range of -0.14 to 0.21 V (vs. Fc/Fc(+)) and show substantial dependence on the electron withdrawing properties of the substituents. The charge transfer character of the bands present in the range 365-395 nm was confirmed based on UV-VIS spectroelectrochemical experiments. Different assemblies of complex molecules are influenced by the electron withdrawing properties of the 5,5'-substituents, leading to supramolecular dimers (1, 2 and 4) and linear polymeric self-assembly (3). An in vitro study of representative complex 1 showed protein tyrosine phosphatase activity inhibition higher than that of suramin but lower than those of oxidovanadium(IV) sulphate and bis(maltolato)oxidovanadium(IV).

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