It is an oxidizing agent, as are all perchlorates.
Rubidium perchlorate can be obtained through the careful heating of a rubidium chlorate solution, leading to a disproportionation reaction with the release of oxygen gas:[3] When heated, it decomposes into the chloride and oxygen:[4] It has two polymorphs.
Below 279 °C, it crystallizes in orthorhombic crystal system with lattice constants a = 0.927 nm, b = 0.581 nm, c = 0.753 nm.
Over 279 °C, it has a cubic structure with lattice constant a = 0.770 nm.
[1] Table of solubility in water:[1]