Syntheses and structures of μ-[N,N′-bis(2-aminoethyl)-1,2-ethanediamine-N1,N1′,N2,N2′]-bis[N,N′-(bis(2-aminoethyl)-1,2-ethanediamine-N,N′,N″,N‴)]dinickel(II) perchlorate and 4,4′-biphenyldisulfonate