trans-Di­bromido­tetra­kis­(5-methyl-1H-pyrazole-κN 2)manganese(II)

The title compound was synthesized using Mn(CO)₅Br. The manganese atom is situated on a crystallographic inversion center. The supra­molecular architecture is characterized by several inter­molecular C—H⋯N, N—H⋯Br and C—H⋯π inter­actions.

The title compound, trans-di­bromido­tetra­kis­(5-methyl-1H-pyrazole-κN ²)manganese(II), [MnBr₂(C₄H₆N₂)₄] or [Mn(3-MePzH)₄Br₂] (1) crystallizes in the triclinic P

space group with the cell parameters a = 7.6288 (3), b = 8.7530 (4), c = 9.3794 (4) Å and α = 90.707 (4), β = 106.138 (4), γ = 114.285 (5)°, V = 542.62 (5) ų, T = 120 K. The asymmetric unit contains only half the mol­ecule 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 supra­molecular architecture is characterized by several inter­molecular C—H⋯N, N—H⋯Br, and C—H⋯π inter­actions. Earlier, a polymorphic structure of [Mn(3-MePzH)₄Br₂] (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) Å and α = 105.12 (4), β = 114.98 (4), γ = 92.90 (3)°, V = 558.826 (5) ų, T = 295 K]. A varying supra­molecular 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)₄Br₂] isomorphic to 1 and the analogous chloro derivatives of Fe^II, Co^II and Cu^II are also known.

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