Six-coordinate NbF5 and TaF5 complexes with tertiary mono-phosphine and -arsine ligands

- Synthesis of the first complexes of NbF5 and TaF5 with monodentate phosphine and arsine ligands.
- Characterisation of the first complexes of NbF5 and TaF5 with 6-coordinate metal centres with P or As ligands.
- Comparisons of the properties of these complexes with those containing 8-coordinate cations [MF4(diphosphine)2]+.