Sinteza, karakterizacija i redoks ponašanje Pt(II) i Pt(IV) kompleksa sa N,N i N,S ligandima

Abstract

U priloţenoj disertaciji su opisane sinteze, karakterizacija i oksido-redukciona svojstva dialkil estara N,N'-metilen-(S,S)-etilendiamin-N,N'-di-2-(3-cikloheksil) propanske kiseline, njima odgovarajućih kompleksa Pt(IV) kao i kompleksa Pt(II) sa tiofenolat-oksazolinskim ligandom. Spektroskopska karakterizacija sintetisanih jedinjenja je uraĊena standardnim metodama: infracrvenom i Ulj/Vid spektroskopijom, masenom spektrometrijom i NMR spektroskopijom (1D-1H i 13C; 2D-COSY, HSQC, HMBC tehnikama) dok je sastav jedinjenja potvrĊen elementalnom analizom. Struktura kompleksnih jedinjenja platine(II), [Pt(S-Phoz)2] i [Pt(η2S-Phoz)(η1S-Phoz)(PPh3)], odreĊena je i primenom rendgenske strukturne analize. Dialkil estri N,N'-metilen-(S,S)-etilendiamin-N,N'-di-2-(3-cikloheksil)propanske kiseline su dobijeni u reakciji reduktivnog metilovanja dialkil estara (S,S)-etilendiamin-N,N'-di-2-(3-cikloheksil)propanske kiseline triacetoborhidridom i formaldehidom u odgovarajućem stehiometrijskom odnosu. Sintetisani ligandi su reakcijom sa kalijum-heksahloridoplatinatom(IV) dali odgovarajuće komplekse platine(IV), oktaedarske geometrije sa N,N bidentatno vezanim ligandima. Dodatno je za ovu klasu jedinjenja ispitana citotoksiĉna aktivnost na razliĉitim ćelijskim linijama (A375, B16, CT26CL25, HCT116, PC3 i U251). Tiofenolat-oksazolinski ligand, Li(SPh-oz), je s obzirom na prisustvo dva razliĉita donorska atoma (azota i sumpora) pokazao razliĉite naĉine koordinovanja za platinski metalni centar. Prvobitno je reakcijom Li(SPh-oz) sa kalijum-tetrahloridoplatinatom(II) sintetisan [Pt(S-Phoz)2] kompleks deformisane kvadratno-planarne geometrije. Izolovani monokristalni produkt ovog jedinjenja je ukazao na S,S-trans raspored liganada oko metalnog centra. Zatim je u reakciji istog liganda sa cis-bis(trifenilfosfin)platina(II)-hloridom dobijen [Pt(η2S-Phoz)(η1S-Phoz)(PPh3)]...

An enclosed dissertation describes the synthesis, characterization and oxidoreductive properties of dialkyl esters of N,N′-methylene-(S,S)-ethylenediamine-N,N′-di-2-(3-cyclohexyl)propanoic acid, their corresponding Pt(IV) complexes as well as Pt(II) complexes with thiophenolate-oxazoline ligand. Spectroscopic characterization of the synthesized compounds was performed by standard methods: infrared and UV/Vis spectroscopy, mass spectrometry and NMR spectroscopy (1D-1H and 13C and 2D-COSY, HSQC, HMBC techiques) while the compounds' content was confirmed by elemental analysis. The structures of Pt(II) species, [Pt(S-Phoz)2] and [Pt(η2S-Phoz)(η1S-Phoz)(PPh3)], were determined using X-ray structural analysis. Dialkyl esters of N,N′-methylene-(S,S)-ethylenediamine-N,N′-di-2-(3-cyclohexyl)propanoic acid were obtained by reductive methylation of the parent compounds (dialkyl esters of (S,S)-ethylenediamine-N,N′-di-2-(3-cyclohexyl)propanoic acid) adding triacetoxyborohydride and formaldehyde in appropriate stoichiometric amounts. A reaction between synthesized ligands and potassium tetrachloroplatinate(II) afforded octahedral Pt(IV) complexes giving rise to N,N bidentate coordination. The cytotoxic activity toward various cancer cell lines (A375, B16, CT26CL25, HCT116, PC3 and U251) was additionally investigated for this class of compounds. Thiophenolate-oxazoline ligand, Li(SPh-oz) demonstrated different coordination modes due to the presence of two donor atoms (nitrogen and sulphur). Primarily, [Pt(S-Phoz)2] complex of distorted square planar geometry was obtained in a reaction of Li(SPh-oz) with potassium hexachloroplatinate(IV). The isolated monocrystal product of the specie indicated on S,S-trans arrangement of the ligands around the metal center. Nonetheless, a reaction between the identical ligand and cis-bis(triphenylphosphine)platinum(II) chloride afforded [Pt(η2S-Phoz)(η1S-Phoz)(PPh3)] complex for which 31P NMR spectroscopy and X-ray structural analysis confirmed...