The polymeric title compounds, namely catena-poly[[[di - but-2-enoato- 3 O:O,O′;3 O,O′:O′-bis-[diaqua-dibut-2- enoato-O;2 O,O′-neodymium(III)]] - 4,4′-bipyridyl N,N′-dioxide-2 O:O′] 4,4′-bipyridyl N,N′-dioxide solvate] and ...