Likewise no one in Germany would ask Russia to buy bonds. Like China, Russia has lots of cash. But unlike China, no one would trust Russia. Besides, the Euro Zone is a German show. Russia would be rigidly excluded. Nor would Russia want to participate in the new kind of German empire with expansionist ambitions.
An interesting P.S. Is provided by TUI, a travel agency. It asked Greek hotels to accept payment in the new Greek currency next year if they drop out of the Euro Zone. The Greeks were offended. No one would ask Italy such a question. And no one would even talk to Russia.