Smaller is smarter in a new cobalt(II) imide: intermolecular interactions involving pyrazine versus the larger aromatic quinoxaline

Abstract

The synthesis of one symmetric and one non-symmetric ligand based on imide, quinoxaline and pyrazine moieties are reported. The symmetric ligand, N-(2-quinoxalylcarbonyl)-2-quinoxalinecarboxamide (Hquinoxquinox), is structurally characterised as Hquinoxquinox·d₆DMSO. The non-symmetric ligand, N-(2-pyrazylcarbonyl)-2-quinoxalinecarboxamide (HLquinoxpz), was used to prepare the cobalt(II) complex [Co^II(quinoxpz)₂]·CH₃OH, which was observed to remain high spin at 90 K. The structures of HLquinoxquinox·d₆DMSO and [Co^II(quinoxpz)₂]·CH₃OH are evaluated with regard to their potential to produce spin crossover (SCO) behaviour and for the construction of three-dimensional coordination polymers.

Keywords:

• imide ligands
• cobalt(II) complex
• quinoxaline, pyrazine
• crystallography
• high-spin
• π-π interactions

Supplemental data

Supplemental data for this article can be accessed here: http://dx.doi.org/10.1080/10610278.2015.1075535.

Acknowledgements

We are grateful to the University of Otago for funding this research (including the award of Postgraduate Scholarships to MGC and RGM), and for the invitation to contribute to this special issue featuring supramolecular chemistry in Australia and New Zealand.

Disclosure statement

No potential conflict of interest was reported by the authors.