Synthesis, crystal structure and Hirshfeld surface analysis of the hybrid salt bis(2-methylimidazo[1,5-a]pyridin-2-ium) tetrachloridomanganate(II)

Abstract

The 0-D hybrid salt bis(2-methylimidazo[1,5-a]pyridin-2-ium) tetrachloridomanganate(II), (C8H9N2)2[MnCl4] or [L]2[MnCl4], consists of discrete L+ cations and tetrachloridomanganate(II) anions. The fused heterocyclic rings in the two crystallographically non-equivalent monovalent organic cations are almost coplanar; the bond lengths are as expected. The tetrahedral MnCl42– dianion is slightly distorted with the Mn—Cl bond lengths varying from 2.3577 (7) to 2.3777 (7) Å and the Cl—Mn—Cl angles falling in the range 105.81 (3)–115.23 (3)°. In the crystal, the compound demonstrates a pseudo-layered arrangement of separate organic and inorganic sheets alternating parallel to the bc plane. In the organic layer, pairs of centrosymmetrically related trans-oriented L+ cations are π-stacked. Neighboring MnCl42– dianions in the inorganic sheet show no connectivity, with the minimal Mn...Mn distance exceeding 7 Å. The Hirshfeld surface analysis revealed the prevalence of the non-conventional C—H...Cl—Mn hydrogen bonding in the crystal packing.

Keywords

• crystal structure
• organic–inorganic hybrid
• pseudo-layered structure
• 2-pyridinecarbaldehyde