Trends In Stability of Higher Oxidation States

TiX4 ( tetrahalides ) , VF5  and CrF6 are having highest oxidation numbers .

Mn , for its +7 state , is not represented in simple halides but MnO3F is known .  

You will find beyond Mn has trihalide except FeX3 and CoF3 . 

Due to higher lattice energy or higher bond enthalpy , fluorine can stabilise the highest oxidation states .