Synthesis and structural characterization of four andsi̇x coordinated nickel(ii) dithiophosphonate complexes

In this thesis, five new dithiophosphonic acids ((p-MeO-C6H4)PS(SH)(OR), HLn, (n= 1-5); R= 3-pentyl-, HL1; R= 1-phenyl-1-propyl-, HL2; R= 4-tert-butyl benzyl-, HL3; R= diphenylmethyl-, HL4; R= 4-tert-butylcyclohexyl-, HL5) were prepared by the reaction of Lawesson reagent (LR, 2,4-Bis(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane 2,4-Disulfide) with the 5 alcohols (3 of the aromatic and the others aliphatic, 3-pentanol, 1-phenyl-1-propanol, 4-tert-butylbenzyl alcohols, diphenylmethanol, 4-tert-butylcyclohexanol). As the crude acids were viscous liquids and difficult to purify they were converted to their ammonium salts ([NH4Ln]) for purification through crystallization. Four coordinated which is square planar Ni(II) complexes of the dithiophosphonates ([Ni(Ln)2]) were synthesized in methanol medium and purified with ligands. The reaction between these square planar complexes and pyridine was carried out to produce six coordinated pyridine derivatives ([Ni(Ln)2(py)2]). The molecular and crystal structure of [Ni(L2)2(py)2] was determined by X-ray crystallography. Square planar Ni(II) complexes were of diamagnetic while octahedral complexes have paramagnetic properties. Structures of the compounds were elucidated with the help of elemental analysis, mass spectroscopy, FTIR, Raman, NMR (1H, 13C, 31P), spectroscopy and magnetic susceptibility respectively. The solid state structure of the [Ni(Ln)2(py)2] was characterized by X-ray crystallography. Key Words : Dithiophosphonic Acid, Dithiophosphonate Complexes, Dithiophosphinate complexes, Lawesson's Reagent. This thesis is supported by the Project Coordination Application and Research Center of Bozok University [BAP 6602c-FEF/17-120].