trans-Di-bromido-tetra-kis-(5-methyl-1H-pyrazole-κN(2))manganese(II).

The title compound, trans-di-bromido-tetra-kis-(5-methyl-1H-pyrazole-κN (2))manganese(II), [MnBr(2)(C(4)H(6)N(2))(4)] or [Mn(3-MePzH)(4)Br(2)] (1) crystallizes in the triclinic P space group with the cell parameters a = 7.6288†(3), b = 8.7530†(4), c = 9.3794†(4)†à and α = 90.707†(4), β = 106.138†(4), γ = 114.285†(5)°, V = 542.62†(5)†à (3), T = 120†K. The asymmetric unit contains only half the mol-ecule with the manganese atom is situated on a crystallographic inversion center. The 3-MePzH ligands are present in an AABB type manner with two methyl groups pointing up and the other two down. The supra-molecular architecture is characterized by several inter-molecular C-H⋯N, N-H⋯Br, and C-H⋯π inter-actions. Earlier, a polymorphic structure of [Mn(3-MePzH)(4)Br(2)] (2) with a similar geometry and also an AABB arrangement for the pyrazole ligands was described [Reedijk et al. (1971 ▸). Inorg. Chem. 10, 2594-2599; a = 8.802†(6), b = 9.695†(5), c = 7.613†(8)†à and α = 105.12†(4), β = 114.98†(4), γ = 92.90†(3)°, V = 558.826†(5)†à (3), T = 295†K]. A varying supra-molecular pattern was reported, with the structure of 1 featuring a herringbone type pattern while that of structure 2 shows a pillared network type of arrangement along the a axis. A nickel complex [Ni(3-MePzH)(4)Br(2)] isomorphic to 1 and the analogous chloro derivatives of Fe(II), Co(II) and Cu(II) are also known.