It is unlikely that Russia will use bitcoin or another cryptocurrency for international payments in order to circumvent the imposed sanctions. Russia's attack on Ukraine has been going on for half a year, but we see no signs that Russia is trying to use cryptocurrency to circumvent sanctions. Russia trades with China for yuan. By the way, Russia keeps a significant part of its reserve in yuan. Recently there was also information that Russia sold some of its diamonds to India in circumvention of sanctions. India paid her back with her rupees. India and China are just not very friendly with cryptocurrency, so they will not use it. Even if Russia uses cryptocurrency somewhere, it will be a closed deal for the public.