5 shows the stable halides of the 3d series of transition metals The highest oxidation numbers are achieved in TiX4 (tetrahalides), VF5
and CrF6 The +7 state for Mn is not represented in simple halides but
MnO3F is known, and beyond Mn no metal has a trihalide except FeX3
and CoF3 The ability of fluorine to stabilise the highest oxidation state is
due to either higher lattice energy as in the case of CoF3, or higher bond
enthalpy terms for the higher covalent compounds, e