A (μ-O)(μ-Br)ReIV2 metal–metal triple bond complex with a bridging tridentate ligand: Synthesis, structure and DFT study

• Published in: Inorganic chemistry communications Vol. 49; pp. 5 - 7
• Main Authors: Mukiza, J., Gerber, T.I.A., Hosten, E., Taherkhani, F., Nahali, M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2014
• Subjects: Chelate-bridged; DFT; Noncollinear spin; Orotic acid; Rhenium (IV); Triple bond; Orotic acid; Rhenium (IV); Triple bond; DFT; Chelate-bridged; Noncollinear spin
• ISSN: 1387-7003; 1879-0259
• DOI: 10.1016/j.inoche.2014.09.005

The reaction of trans-[ReOBr3(PPh3)2] with 5-amino-orotic acid (H2aoa) in ethanol led to the isolation of the triply-bridged dimer [ReIV2(μ-O)(μ-Br)(μ-aoa)Br(OEt)2(PPh3)2] (1). The compound has a ReRe bond distance of 2.5526(4) Å. The dianionic bridging ligand aoa coordinates bidentately via an amido nitrogen and carboxylate oxygen to one Re ion, and monodentately through a neutral carbonylic oxygen to the second metal ion. Density functional theory (DFT) calculation shows that the presence of the rhenium atoms leads to a noncollinear spin phase arrangement for the bridging atoms. The reaction of trans-[ReOBr3(PPh3)2] with 5-amino-orotic acid (H2aoa) in ethanol led to the isolation of the triply-bridged dimer [ReIV2(μ-O)(μ-Br)(μ-aoa)Br(OEt)2(PPh3)2]. The compound has a ReRe triple bond distance of 2.5526(4) Å. The dianionic bridging ligand aoa coordinates bidentately via an amido nitrogen and carboxylate oxygen to one Re ion, and monodentately through a neutral carbonylic oxygen to the second metal ion. [Display omitted] •ReIVReIV triple bond•Bridging tridentate O2N-donor ligand•Noncollinear spin phase arrangement•Crystal structure