# Why is SF6 inert towards hydrolysis? [duplicate]

Why is $\ce{SF6}$ inert towards hydrolysis? Would not $\ce{H - F}$ bonds be created in water which is much stable and has a high negative enthalpy of formation. This hydrogen bond making must disintegrate the whole compound.

• – Ivan Neretin Jun 12 '18 at 18:57

In short its kinetically stabilised, attack at S is close to impossible due to steric hindrance and rigidity of FSF angles. Thermodynamically with water it is very unstable with respect to HF$_{aq}$ and H$_2$SO$_4$. Creepy ...
• The group electronegativity (see Huheey) of -SF$_5$ is about 3.0, that means F in F-SF$_5$ is not very strongly polarized (F is anyway quite hard), so its a bad hydrogen bond acceptor, thus the F-S bond is not really substantially weakend. The only "dangerous" attack would be a nucleophilic one at sulphur by water lone pairs, but that is sterically hindered. – Raphael J.F. Berger Feb 11 '19 at 14:42