Manganese(II)complexes of 3,6,9-trioxaundecanedioic acid (3,6,9-tddaH(2)): X-ray crystal structures of [Mn(3,6,9-tdda)(H2O)(2)]center dot 2H(2)O and {[Mn(3,6,9-tdda)(phen)(2)center dot 3H(2)O]center dot EtOH}(n)

3,6,9-trioxaundecanedioic acid (3,6,9-tddaH(2)) reacts with Mn(CH3CO2)(2) .4H2O in ethanol to give [Mn(3,6,9-tdda)]. H2O (1). Recrystallization of 1 from methanol gives crystals of [Mn(3,6,9-tdda) (H2O)(2)]. 2H(2)O (2). Complex 1 reacts with an ethanolic solution of 1,10-phenanthroline (phen) to give {[Mn(3,6,9-tdda)(phen)(2)]. 3H(2)O . EtOH}(n) (3). All of the complexes are extremely water soluble. Complexes 2 and 3 were structurally characterised. The manganese(II) ion in 2 is seven coordinate, with an approximately pentagonal bipyramidal O-7 coordination sphere. The axial donors are water molecules and the pentagonal plane is occupied by the diacid, acting as a pentadentate ligand through the three ethereal oxygens and one oxygen atom from each of the carboxylate functions. In complex 3 the manganese(II) ion is six-coordinate, being bound to two bidentate phenanthroline ligands and to the carboxylate oxygen atoms from two symmetry related diacids which are coordinated in a cis fashion. The structure consists of polymeric chains, with diacid ligands bridging the manganese ions. There is pi-pi stacking of pairs of phenanthroline ligands on adjacent chains, running along both the z and y directions. (C) 1997 Elsevier Science Ltd.