Sinteza i karakterizacija kompleksa Zn(II), Cu(I), Cu(II) I Ni(II) sa derivatima 3-acetilpiridina i 2-hinolinkarboksaldehida

Abstract

U ovom radu opisana je sinteza, strukturna karakterizacija, teorijski proračuni, magnetna merenja i biološka aktivnost kompleksa Ni(II) sa kondenzacionim derivatom 2-hinolinkarboksaldehida i dihidrazida malonske kiseline, kompleksa Zn(II) sa semikarbazonom 3-acetilpiridina i kompleksa Cu(I) i Cu(II) sa 3-acetilpiridinom i tiocijanatom. Rendgenska strukturna analiza pokazala je da su u neutralnom dinuklearnom oktaedarskom kompleksu nikla(II) dva dvostruko deprotonovana molekula liganda koordinovana preko karbonilnog kiseonika, piridinskog i azometinskog azota za svaki od Ni(II) jona. Višestruke slabe intramolekulske CH····π interakcije stabilizuju geometriju kompleksa Ni(II). Podaci dobijeni magnetnim merenjem ukazuju na slabe intradimerne antiferomagnetne interakcije koje su posledica velikog rastojanja između Ni(II) jona. Tetraedarski kompleks Zn(II) sa Schiff-ovom bazom 3-acetilpiridina i semikarbazida okarakterisan je u rastvoru NMR spektroskopijom i rendgenskom strukturnom analizom u čvrstom stanju. Pored većeg broja potencijalnih donorskih atoma ligand se za Zn(II) jon koordinovao monodentatno. Teorijski proračuni su pokazali da je struktura Zn(II) kompleksa kod koje su dva molekula liganda monodentatno koordinovana preko piridinskog azota stabilnija od hipotetičke, u kojoj bi jedan ligand bio bidentatno koordinovan preko azometinskog azota i karbonilnog kiseonika. Kompleks poseduje umerenu antibakterijsku, antifungalnu i citotoksičnu aktivnost, dok je nekoordinovan ligand...

In this work the synthesis, structural characterization, theoretical calculations, magnetic measurements and biological activity of the Ni(II) complex with condensation derivative of 2-quinolinecarboxaldehyde and malonic acid dihydrazide, Zn(II) complex with 3-acetylpyridine semicarbazone and Cu(I) and Cu(II) complexes with 3-acetylpyridine and thiocyanate are described. X-ray analysis showed that neutral binuclear octahedral Ni(II) complex is coordinated with two di-deprotonated molecules of the ligand through carbonyl oxygen, pyridine and azomethine nitrogen. Multiple weak intramolecular CH····π (chelate ring) interactions support the molecular geometry of the Ni(II) complex. Due to long Ni(II) – Ni(II) distance weak intradimer antiferromagnetic interactions were observed by magnetic measurements. A Schiff base of 3-acetylpyridine with semicarbazide as well as the corresponding tetrahedral Zn(II) complex were characterized in solution by NMR spectroscopy and in solid state by the X-ray structure analysis. It is interesting to note that the ligand was coordinated as a monodentate although there are several donor atoms in it. Computational studies showed that such structure with two molecules of ligand coordinated as monodentate through pyridine nitrogen is more stable than the hypothetical structure with one ligand bound as a bidentate through azomethine nitrogen and carbonyl oxygen. The complex exhibited moderate antibacterial, antifungal and cytotoxic activities while the...