Metal-phenoxyalkanoic acid interactions. Part 9 the x-ray crystal and molecular structure of bis[μ-2,4,5-triclorophenoxyacetato- O] -bis-[ trans-diaqua(2,4,5-trichlorophenoxyacetato)manganese(II)]. The third chemical polymorph in the series of manganese-2,4,5-T coordination complexes

Abstract

The third chemical polymorph of the manganese(II)-[2,4,5-trichlorophenoxyacetic acid] series a complex with formula [Mn 2(2,4,5-T) 4(H 2O) 4], has been prepared and its crystal structure determined by X-ray diffraction. Crystals are monoclinic, space group P2 1/c with two dimeric molecules in a cell of dimensions a = 21.471(4), b = 7.770(3), c = 13.064(4) Å, β = 90.41(2)°. The dimers are centro-symmetric with bis-oxo bridges [MnO, 2.35, 2.45(2) Å] from carboxylate oxygens of 2,4,5-T molecules. The distorted pyramidal MO 5 stereochemistry about each Mn is completed by two transrelated waters [MnO, 2.28, 2.31(2) Å] and an oxygen of a second unidentate 2,4,5-T ligand [MnO, 2.46(2) Å]. Symmetrically disposed about the sixth coordination position are two long contacts to the ether oxygen and a ring-substituted chlorine of the bridging 2,4,5-T molecule [MnO, 2.96(2) Å; MnCl, 3.07(2) Å]. The manganese sites are only partially occupied (42%) indicating considerable Mn lability in a very stable lattice consisting of water and 2,4,5-T molecules.