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

摘要

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 center dot d(6)DMSO. The non- symmetric ligand, N-( 2- pyrazylcarbonyl)- 2- quinoxalinecarboxamide ( HLquinoxpz), was used to prepare the cobalt( II) complex [ Co II ( quinoxpz) 2] center dot CH3OH, which was observed to remain high spin at 90 K. The structures of HLquinoxquinox center dot d6DMSO and [ Co II ( quinoxpz) 2] center dot CH3OH are evaluated with regard to their potential to produce spin crossover ( SCO) behaviour and for the construction of three- dimensional coordination polymers.