Bis(O-n-butyl dithiocarbonato-κ2 S,S′)bis(pyridine-κN)manganese(II)

The structure of the title manganese complex, [Mn(C5H9OS2)2(C5H5N)2] or [Mn(S2CO-n-Bu)2(C5H5N)2], consists of discrete monomeric entities with Mn2+ ions located on centres of inversion. The metal atom is coordinated by a six-coordinate trans-N2S4 donor set with the pyridyl N atoms located in the apical positions. The observed slight deviations from octahedral geometry are caused by the bite angle of the bidentate κ2-S2CO-n-Bu ligands [69.48 (1)°]. The O(CH2)3(CH3) chains of the O-n-butyl dithiocarbonate units are disordered over two sets of sites with an occupancy ratio of 0.589 (2):0.411 (2).

The structure of the title manganese complex, [Mn(C 5 H 9 OS 2 ) 2 (C 5 H 5 N) 2 ] or [Mn(S 2 CO-n-Bu) 2 (C 5 H 5 N) 2 ], consists of discrete monomeric entities with Mn 2+ ions located on centres of inversion. The metal atom is coordinated by a six-coordinate trans-N 2 S 4 donor set with the pyridyl N atoms located in the apical positions. The observed slight deviations from octahedral geometry are caused by the bite angle of the bidentate 2 -S 2 CO-n-Bu ligands [69.48 (1) ]. The O(CH 2 ) 3 (CH 3 ) chains of the O-n-butyl dithiocarbonate units are disordered over two sets of sites with an occupancy ratio of 0.589 (2):0.411 (2).
The structure of the manganese compound consists of centrosymmetric monomeric entities. Fig. 1 shows a perspective view of the monomeric unit with the atomic numbering scheme. The Mn(II) atom is in a distorted octahedral environment surrounded by two chelating xanthate ligands and two pyridines ligands. All managanese dithiocarbonato compounds structurally described so far are also octahedral complexes with an N 2 S 4 donor set (Klevtsova & Glinskaya, 1997;Câmpian et al., 2010;Kirichenko et al., 1994), but the other four such compounds are all bipyridine derivative complexes and the title compound is the only one in which the two none-sulfur donor atoms occupy the apical sites. The four sulfur atoms and the manganese atom are almost coplanar. The bond angles around the manganese atom are in the range of 69.48 (1)° to 180°.
The Mn-S bond lengths involving the xanthate ligands range are 2.5862 (4) and 2.6556 (5)Å and are in good agreement with those reported for other analogous Mn-dithiocarbonato complexes. The variation of the Mn-S bond distances in the complex of ca 0.07Å is not very pronounced and the bidentate κ 2 -S 2 CO-n-Bu ligands may thus be considered to be chelating in a symmetric (isobidentate) mode. The resulting N 2 S 4 donor set defines an approximately octahedral geometry with distortions arising from the steric constraints imposed by the restricted bite distances of the chelating xanthate ligands. The two S atoms forming the longer Mn-S bonds are approximately trans to each other. The short value of 1.333 (8)Å for the C6-O1 bond lengths is consistent with a significant contribution of the resonance form of the xanthate anion that features a formal C═O bond and negative charges on each of the S atoms. The two pyridine rings are coplanar and almost perfectly perpendicular to the O1/S1/S2/O1 i /S1 i /S2 i plane. Symmetry code: (i) -x+1, -y+1, -z+2.
Packing of the title compound is facilitated mostly by shape recognition through van der Waals forces. A small number of C-H···O interactions (originating from the alkyl and aromatic C-H groups) can be observed ( 3H 2 O (11.64 g, 0.05 mole) was added directly into the reaction flask. The contents were stirred to dissolve the salt completely. About 30 ml of pyridine were added to give a light yellow solution and stirring was continued supplementary materials sup-2 for another hour. Any insoluble matter was removed by filtration and slow evaporation of the reaction mixture at room temperature yielded 70% of the title compound in the form of yellow crystals. M.p. = 368 K. Elemental analyses: Found (Calc.) for: C 46.02 (46.99); H 5.33 (5.51); N 4.58 (5.47).

Refinement
Reflections 1 0 0 and 0 0 2 were partially obstructed by the beam stop and were omitted from the refinement. The O(CH 2 ) 3 (CH 3 ) chain of the O-n-butyldithiocarbonato group is disordered over two positions with an occupancy ratio of 0.589 (2) to 0.411 (2). The C-O bond distance was restrained to be the same within a standard deviation of 0.02, and the ADPs of equivalent atoms were set to be identical. Hydrogen atoms were placed in calculated positions with C-H distances of 0.95, 0.99 and 0.99Å for aromatic, methyl and methylene H atoms, respectively, and were refined with an isotropic displacement parameter U iso of 1.5 (methyl) or 1.2 times (aromatic) that of U eq of the adjacent carbon atom. Methyl H atoms were allowed to rotate around the C-C bond axis at a fixed angle to best fit with the experimental electron density. Fig. 1. Perspective view of the monomeric unit with the atomic numbering scheme. Displacement ellipsoids are drawn at with 50% probability level. The minor disordered alkyl chain is shown for one half of the molecule. Hydrogen atom lables, labels of less than 50% occupied atoms and of symmetry created atoms are omitted for clarity. Fig. 2. Packing plot, view down the b axis (displacement ellipsoids for non-H atoms). Less than 50% occupied atoms are omitted for clarity. Blue dashed lines represent close contacts (less than the sum of the van der Waals radii of the respective atoms) such as C-H···O and S···S contacts.