The reactions of beryllium atoms with dioxygen reinvestigated by matrix isolation infrared absorption spectroscopy. Besides the previously reported linear OBeO and cyclic Be(2)O(2) molecules, two interconvertible beryllium ozonide complexes were prepared and characterized. The BeOBe(eta(2)-O(3)) complex was formed on annealing, which is characterized to be a side-on bonded ozonide complex with a planar C(2 nu) structure. The BeOBe(eta(2)-O(3)) complex isomerized to the BeOBe(eta(1)-O(3)) isomer under visible light excitation, which is an end-on bonded ozonide complex with planar C(s) symmetry. These two isomers are interconvertible; that is, visible light induces the conversion of the side-on bonded complex to the end-on bonded isomer, and vice versa on annealing. In addition, evidence is also presented for the linear BeOBeOBe cluster.