Van der Merwe, Kina Ann, Visser, Hendrik G., Venter, Johan A., Van der Merwe, Kina Ann, Visser, Hendrik G., and Venter, Johan A.
English: The aim of the study was to synthesize several novel Co(II)-, Co(III)- and Cr(III) complexes using an O,O-bidentate ligand, methylene diphosphonate, and to characterize these complexes by various means. Characterization of the complexes was done by elemental analysis, infrared spectroscopy, nuclear magnetic resonance spectroscopy (NMR), single X-ray crystallography and X-ray photoelectron spectroscopy (XPS). The methylene diphosphonate ligand was selected as it is a ligand employed in a bone imaging agent in the radiopharmaceutical sector. Little is known about the structure and coordination chemistry of metal complexes with methylene diphosphonate. Single crystal X-ray crystallographic structure determinations of six new structures were completed: (1) Pyridinium diaquabis(methylenediphosphonato)chromate(III) tetrahydrate (2) Potassium diaquabis(methylenediphosphonato)cobaltate(III) (3) Potassium diaquadihydroxy(methylenediphosphonato)cobaltate(III) (4) Diammonium diaquabis(methylenediphosphonato)cobaltate(II) (5) Disodium diaquabis(methylenediphosphonato)cobaltate(II) dihydrate (6) Dicesium diaquabis(methylenediphosphonato)cobaltate(II) Each complex has a slightly distorted octahedral geometry. The cobalt or chromium ion in each complex is coordinated to four oxygen atoms derived from two methylene diphosphonate ligands, except for K[Co(CH4O6P2)(OH)2(H2O)2] which has two oxygen atoms from one methylene diphosphonate ligand coordinated to it. In addition each complex has two aqueous molecules which are coordinated to the metal center. Two phosphonate oxygen atoms from the ligand, methylene diphosphonate define the equatorial plane, whereas the water molecules reside in the axial positions. See Table in full text PDF. These complexes correlate with other similar complexes but the occurrence of similar structures in literature is very limited, showing that this field is open to further study. We were unable to perform any meaningful studies on these complexes, Afrikaans: Die doel van die studie was die sintese van verskeie oorspronklike Co(II)-, Co(III)- en Cr(III) komplekse met die gebruik van `n O,O-bidentate ligand, metileen difosfonaat, en die karakterisering van hierdie komplekse deur verskillende tegnieke. Karakterisering van die komplekse is gedoen deur elementele analise, infrarooi spektroskopie, kernmagnetieseresonans (KMR) spektroskopie, enkelkristal X-straal kristallografie asook X-straal foto-elektron spektroskopie (XPS). Die metileen difosfonaat ligand is gekies aangesien dit gebruik word as `n ligand in `n been beeldingsagent in die radiofarmaseutiese bedryf. Die struktuur en koördinasiechemie van metaalkomplekse met metileen difosfonaat is redelik onbekend. Enkelkristal X-straal kristallografiese struktuurbepalings van ses nuwe strukture is voltooi: (1) Piridinium diakwabis(metileendifosfonato)chromaat(III) tetrahidrate (2) Kalium diakwabis(metileendifosfonato)kobaltaat(III) (3) Kalium diakwadihidroksie(metileendifosfonato)kobaltaat(III) (4) Diammonium diakwabis(metileendifosfonato)kobaltaat(II) (5) Dinatrium diakwabis(metileendifosfonato)kobaltaat(II) dihidrate (6) Disesium diakwabis(metileendifosfonato)kobaltaat(II) Elke kompleks het `n effens verwronge oktahedriese geometrie. Die kobalt of chroom ioon in elke kompleks is aan vier suurstofatome gekoördineer; afkomstig van twee metileen difosfonaat ligande, behalwe vir K[Co(CH4O6P2)(OH)2(H2O)2] wat twee suurstofatome van een metileen difosfonaat ligand daaraan gekoördineer het. Benewens die bogenoemde het elke kompleks twee akwa molekule aan die metaalsenter gekoördineer. Twee fosfonaat suurstofatome van die ligand, metileen difosfonaat definieer die ekwatoriale vlak, terwyl water molekule die aksiale posisies betrek. Sien Tabel in volteks PDF. Hierdie komplekse stem ooreen met ander soortgelyke komplekse maar die voorkoms van soortgelyke strukture in die literatuur is baie beperk, wat aantoon dat hierdie veld oop is vir verdere studiemoontlikhede. Geen be, University of the Free State, National Research Foundation (NRF)