By pure, I mean no matter, no light, no spacetime. Absolutely nothing. Assuming that space-time does not get bent due to this, what would be the consequences? My best guess would be that all photons of all wavelengths would be reflected due to them not being able to travel into nothing and thus they just "bounce off" and that matter would just be stopped by the electron shells getting pushed by themselves 'cause electromagnetism would also "bounce off" and thus "push the electron back more as it got closer". The "pure nothing" would be completely unchanging due to nothing in the universe (well apart from maybe black holes) being able to change its state.
Also, would having a lack of spacetime in a certain area cause spacetime to become distorted accordingly? Let me clarify something though, this nothing is simply a lack of spacetime in a specific part of the universe that isn't moving according to a specific reference frame and never accelerates/changes state because it is nothing. It is nothing that is "localised in spacetime by replacing a small section of it".