Metallocenylphosphazene ring systems and high polymers. Reactions of ferrocenyl- and ruthenocenylphosphazenes with lithiometallocenes and the x-ray structures of N3P3F4(.eta.-C5H4)2Fe, [N3P3F3{(.eta.-C5H4)2Fe}{(.eta.-C5H4)Fe(.eta.-C5H5)}], 1,5-N4P4F6(.eta.-C5H4)2Fe, and 1,5,3,7-N4P4F4[(.eta.-C5H4)2R