The kinetic parameters of gold(III) sorption by unloaded polyurethane foams (PUFs) and PUFs impregnated with some onium cations e.g. tetramethylammonium perchlorate (TMA + ClO4 -), tetrabutylammonium iodide (TBA + I -), and tetraheptylammonium bromide (THA + Br -), have been determined. The retention steps were found to be fast, reached equilibrium in a few minutes and followed a first-order rate equation with an overall rate constant, k, of 0.0076 and 0.007 min -1 , respectively. The thermodynamic characteristics of gold(III) retention by the unloaded PUFs and THA + Brimmobilized PUFs have been critically studied. The negative values of DH and DS are interpreted as the exothermic and spontaneous reaction of gold(III) sorption onto unloaded PUFs and foams impregnated with THA + Br -. The cellular structure of the PUFs sorbent offer unique advantages over conventional bulk-type sorbents in the rapid, versatile effective separation and/or preconcentration of gold ions.

Cyclic β-chloroenaldehyde 1 was used to create a novel series of angular heteroannulated chromones. Condensation of β-chloroenaldehyde 1 with hydrazine derivatives produced chromeno[2,3-b]pyrazolo[3,4-f]quinolines 2, 5 and 6. Also, condensation of compound 1 with some 1,3-N,N-binucleophiles yielded chromeno[2`,3`:6,5]pyrido[2,3-h]quinazolines 7-9. Treating compound 1 with some 1,3-N,C-binucleophiles produced chromeno[2,3-J]phenanthrolines 10, 11, benzoimidazo[1,2-a]chromeno[2,3-J]phenanthroline 12 and chromeno[2,3-J]pyrazolo[3,4-b]phenanthrolines 13, 14. Reacting compound 1 with a diversity of 1The in vitro antimicrobial activity seemed variable inhibitory effect for the prepared compounds.

No abstract

No abstract

No abstract