A new organic-inorganic hybrid salt [L]2[MnCl4] (I) where L + is the 2-methyl-3-(pyridin-2-yl)imidazo[1,5-a]pyridinium cation, is built of discrete organic cations and tetrachloridomanganate(II) anions. The L + cation was formed in situ in the oxidative cyclocondensation of 2-pyridinecarbaldehyde and CH3NH2·HCl in methanol. The structure was refined as a two-component twin using PLATON (Spek, 2020) to de-twin the data. The twin law (-1 0 0 0-1 0 0.5 0 1) was applied in the refinement where the twin component fraction refined to 0.155 14;(1). The compound crystallizes in the space group P21/c with two crystallographically non-equivalent cations in the asymmetric unit, which possess similar structural conformations. The fused pyridinium and imidazolium rings of the cations are virtually coplanar [dihedral angles are 0.89 14;(18) and 0.78 14;(17)°]; the pendant pyridyl rings are twisted by 36.83 14;(14) and 36.14 14;(13)° with respect to the planes of the remaining atoms of the cations. The tetrahedral MnCl4 2- anion is slightly distorted with the Mn-Cl distances falling in the range 2.3469 14;(10)-2.3941 14;(9) 14;Å. The distortion value of 0.044 relative to the ideal tetrahedron was obtained by continuous shape measurement (CShM) analysis. In the crystal, the cations and anions form separate stacks propagating along the a-axis direction. The organic cations display weak p-p stacking. The anions, which are stacked identically one above the other, demonstrate loose packing; the minimum Mn Mn separation in the cation stack is approximately 7.49 14;Å. The investigation of the fluorescent properties of a powdered sample of (I) showed no emission. X-band EPR data for (I) at 293 and 77 14;K revealed broad fine structure signals, indicating moderate zero-field splitting.
|Number of pages||5|
|Journal||Acta Crystallographica Section E: Crystallographic Communications|
|Publication status||Published - 1 Mar 2020|