
%0 Journal Article
%A Smith, G 
%A O'Reilly, EJ 
%A Kennard, CHL 
%T Crystal and molecular structure of Bis(4-amino-3,5,6-trichloropicolinato)-manganese(II) dihydrate
%J Australian Journal of Chemistry
%D 1981/04/01
%V 34
%N 4
%P 891-896
%K 
%R https://doi.org/10.1071/CH9810891
%U https://www.publish.csiro.au/paper/CH9810891 
%X The manganese(II) complex [Mn(picl)2,2H2O]n of the herbicide picloram has been prepared and the crystal and molecular structure determined from three-dimensional X-ray data collected by counter methods. The crystals of the complex are monoclinic, space group 12/a with two complex units in a cell of dimensions a 23&#903;052(5), b 13&#903;840(2), c 6&#903;441(1) Å, &#946; 98&#903;20(1)º. The structure was solved by direct methods and refined by full matrix least squares to unweighted and weighted Rfactors of 0&#903;035 and 0&#903;038 respectively for 887 'observed' reflections. The polymer is best described as having a centrosymmetric two-molecule unit [Mn-O, 2&#903;162(3), 2&#903;246(3) Å] with two oxo bridges between manganese centres through two single carboxylate oxygens of the four substituted picolinate ligands. The two molecules are related by a twofold axis. The units form infinite one-dimensional polymer chains in the c direction through oxo bridges involving one oxygen from the other two picolinate ligands [Mn-Mn 3&#903;636(1)Å]. The bis(bidentate)picolinate bites are completed by the pyridlne nitrogens [Mn-N, 2&#903;313(4) Å] giving a very distorted octahedral MnO4N2 coordination sphere about each manganese [N-Mn-N', 97.0(3)º; O-Mn-O range, 68&#903;9-168.2(3)º; O-Mn-Nrange, 69&#903;9-138&#903;5(3)º]. The lattice waters are involved in hydrogen-bonding interactions which link the polymer in the a crystallographic direction with the uncoordinated carboxylate oxygen ( O&#903;&#903;&#903;O,2&#903;824, 2&#903;936 Å) and the 4-amino groups from the adjacent picolinate ligand (N&#903; &#903;&#903;0, 2&#903;852, 3&#903;030Å). 
