New binuclear complex of bis(2,4,6,8-tetramethyl-2,4,6,8-tetraazabicyclo(3.3.0)octane-3,7-dione-O,O')-diaquatetrakis(nitrato-O,O')-dimanganese(II) monohydrate: Synthesis and crystal structure

摘要

The centrosymmetric binuclear manganese(II) nitrate complex with a bicyclic bis-carbamide, namely, 2,4,6,8-tetramethyl-2,4,6,8-tetraazabicyclo(3.3.0)octane-3,7-dione, or mebicar (Mk) [Mn(C8H14N4O2)(H2O)(NO3)(2)](2) center dot H2O (I), has been synthesized for the first time. The structure of complex I has been solved (CCDC no. 1435139). Crystals of complex I are monoclinic, space group P2(1)/c, a = 12.8108(11) , (b) = 10.0662(2) , c = 18.6367(17) , beta = 136.512(16)A degrees, V = 1654.0(4) (3), rho calcd = 1.659 g/cm(3), Z = 2. Each manganese atom is coordinated to the two oxygen atoms of two Mk molecules related by the symmetry codes (1-x, 2-y, 1-z) and to two bidentate nitrate anions and one water molecule. The coordination polyhedron of the manganese atom is a strongly distorted pentagonal bipyramid. The Mn center dot center dot center dot Mn distance in the complex is 8.7261(9) angstrom.