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

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 MnCl(4)(2-)dianion is slightly distorted with the Mn-Cl bond lengths varying from 2.3577 (7) to 2.3777 (7) A degrees and the Cl-Mn-Cl angles falling in the range 105.81 (3)-115.23 (3)(circle). In the crystal, the compound demonstrates a pseudolayered 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 stacked. Neighboring MnCl42- dianions in the inorganic sheet show no connectivity, with the minimal Mn center dot center dot center dot Mn distance exceeding 7 A degrees. The Hirshfeld surface analysis revealed the prevalence of the non-conventional C-H center dot center dot center dot Cl-Mn hydrogen bonding in the crystal packing.