PREPARATION, CHARACTERIZATION AND CRYSTAL STRUCTURES OF TWO AMINE-OXIME RHODIUM COMPLEXES

Abstract

Abstract Two amine-oxime complexes of rhodium(III) have been synthesized and structurally characterized as model compounds for a study of potential rhodium radiopharmaceuticals. Dichlorobis (2-acetylpyridineoxime)-rhodium(III) crystallizes in space group Pnma with a=13.462(4), b=12.496(2), c=9.661(2)Å, Z=4, Dx =1.819(2)g/cm3. The chloro ligands are trans (av Rh[sbnd]Cl=2.337(2)Å) in the octahedral Rh(III) complex. The oxime oxygens are involved in a short intramolecular hydrogen bond (O[sbnd]O=2.446(4)Å) with the hydrogen atom as well as the rhodium and two chlorine atoms on the mirror. Dichloro-[4,4′-(1,2-ethanediyldiimino)bis(4-methyl-2-pentanone-dioxime)]rhodium (III) crystallizes in space group P212121 with a=14.435(3), b=7.638(9), c=16.596(3)Å, Z=4, Dx =1.667(2)g/cm3. The trans dichoro octahedral complex (av Rh[sbnd]↓ =2.341(11)Å) has cis amine nitrogens (av Rh[sbnd]N=2.079(3)Å) and cis oxime nitrogens (av Rh[sbnd]N=2.030(3)Å). The oxime oxygen atoms are involved in a short intramolecular hydrogen bond (O[sbnd]O=2.423(3)Å). Synthesis and proton magnetic resonance results are included, along with a comparison with other rhodium(III) amine-oxime complex structures.