The structure and dynamics of FeH(DMPE)2(BH4), FeH(DEPE)2(BH4) and FeH(DPrPE)2(BH4): Iron complexes containing monodentate borohydride ligands

✍ Scribed by Murray V Baker; Leslie D Field

• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: English
• Weight: 487 KB
• Volume: 4
• Category: Article
• ISSN: 0268-2605
• DOI: 10.1002/aoc.590040516

✦ Synopsis

Abstract

FeH(DMPE)~2~(BH~4~) [DMPE = 1,2‐bis(dimethylphosphino)ethane] is a stable, diamagnetic complex which can be synthesized readily by borohydride reduction of FeH(DMPE)~2~Cl or by treatment of Fe(DMPE)~2~H~2~ with borane. The complex contains an unsupported BHFe hydrogen bridge. Analogous complexes with bulkier ligands, FeH(DEPE)~2~(BH~4~), [DEPE = 1,2‐bis(diethylphosphino)ethane] and FeH(DPrPE)~2~(BH~4~) [DPrPE = 1,2‐bis(di‐n‐propylphosphino)ethane], are less stable. In all complexes, in solution the borohydride ligand undergoes rapid internal motion, with all four boron‐bound hydrogens interchanging environments. The barriers for BH~4~ reorientation (measured by NMR spectroscopy) are in the sequence FeH(DMPE)~2~(BH)~4~ > FeH(DEPE)~2~(BH)~4~ > FeH(DPrPE)~2~(BH~4~).