MANGANESE(II) N,N'-DIPYRIDOXYLETHYLENE DIAMINE-N,N'-DIACETATE 5,5'-BIS(PHOSPHATE), MnDPDP. B. Fjartoft-Pedersen, L. Ehnebom Tonnesen, J. Klaveness, School of Pharmacy, University of Oslo, B.Tirkkonen and T.Aase, Nycomed Imaging AS, Oslo

The hydrate of the disodiummanganese salt of Mn(II)DPDP¹ is presented. In the hexadentate chelate anion Mn(II) is coordinated to two nitrogens both at a distance of 2.32A, two carboxylate oxygens at 2.19 and 2.20A and two pyridoxyl oxygens at 2.09 and 2.1lA. The other manganese ion is bonded to one carboxylate oxygen at [[chi]]2.20A, one phosphate oxygen at 2.12A and four water molecules at 2.16-2.25A, both coordination polyhedra are more or less regular octahedra. One of the phosphate groups is disordered; two of the oxygen atoms being common for the two orientations of the group, with phosphorous and the other two oxygen atoms occupying two possible sites, P-P' distance 1.69 A and O-O' distance 1.51 A, the other oxygens pointing in opposite direction from the respective phosphorous atoms. The sodium atoms present in the structure are differently sixcoordinated, one of them to two different complex ions and have one carboxylate and one pyridoxyl oxygen atom from each complex and two water molecules as ligands, the other sodium atom is coordinated to two carboxylate oxygens and two phosphate oxygens from different molecules, ligand no 5 and 6 being one of the disordered phosphate sites. The Na-O distances range from 2.23 A to 2.65 A. The crystal contains several water molecules at hydrogen bonding distance in addition to the ones in the coordination sphere. Triclinic P1, Z=2, a=10.793A, b=10.969A, c=18.316A, [[chi]]=97.21deg., [[beta]]=96.26deg., ‡[[gamma]]=94.44deg.

¹Rocklage, S.M.,Cacheris, W.P.,Quay, S.C.,Hahn, F.E. & Raymond,K.N. Inorg. Chem. (1989) 28 477-485.