Can a substance donate a proton without the proton getting accepted by another substance? I have read that the concept of Brønsted and Lowry is based on the fact that acid-base reactions involve the transfer of $\ce{H+}$ ions from one substance to another, and that an acid is a substance that donates a proton to another substance, but:

can a substance donate a proton without the proton getting accepted by another substance? So for example:
$$\ce{AH -&gt; A- + H+}$$
without reacting with another substance?

If yes: Is this a Brønsted-Lowry acid?
The closest thing I can find to this involves a most unlikely proton donor.  Given an appropriate base, sodium hydride donates a proton for encapsulation in the base (rather than forming a localised covalent bond), leaving the valence electrons on sodium (!) in inverse sodium hydride.  The proton is not free (a completely free proton is possible only in plasma), but analogous to complexed metal ion or solvated electron.