The next three members — C4O4, C5O5, and C6O6 — are theoretically possible, but are expected to be quite unstable, and so far they have been synthesized only in trace amounts.
接下来的三个成员——C4O4、C5O5和C6O6——理论上是存在的，但都可能不稳定，现在只能痕量地合成。