Similar structural feature observed in the crystal packing of [Ni(dmit)2] salts of geometrical isomer of methoxycarbonyl pyridinium

The crystal structures of the C–H⋯O hydrogen-bonded, 1:1 complex salts of with [Ni(dmit)2]− 2MMP, 3MMP and 4MMP (ortho-, meta-, and para-methoxycarbonyl N-methyl-pyridinium, respectively) cations with have been investigated. All complex salts formed non-segregated stacks with the anions being sandwiched between layers or dimers of cations. Within these salts, the arrangement of the counter cations are structurally modulated by two weak intermolecular hydrogen bonds between the hydrogen of the pyridinium ring, methyl group or one of the two and the CO group of the cations. The alignment of Ni(dmit)2 molecules is found to be mainly governed by the attached position of methoxycarbonyl group. Powders of (2MMP)[Ni(dmit)2], (3MMP)[Ni(dmit)2] and (4MMP)[Ni(dmit)2] salts exhibited room temperature conductivities of 4.33 × 10−10, 1.80 × 10−6 and 5.60 × 10−6 S cm−1, respectively.

Graphical abstractIn the crystal structure of Ni(dmit)2 salts of three geometrical isomers, 2MMP, 3MMP and 4MMP (see text), MMP’s were found to adopt similar alignment by weak C–H⋯O hydrogen bonds.Figure optionsDownload full-size imageDownload as PowerPoint slide