<p>2-(Aminomethyl)pyrazine has been prepared in five steps from 2-pyrazine carboxylic acid. From this key amine, two new bis-terdentate triazole-based ligands which feature pendant <i>pyrazine</i> groups, <b>P</b><sub><b>Z</b></sub><b>MAT</b> and <b>P</b><sub><b>Z</b></sub><b>MPT</b> (4-amino- and 4-pyrrolyl-3,5-bis{[(2-pyrazylmethyl)amino]methyl}-4H-1,2,4-triazole, respectively), and two dinuclear complexes of them, [Fe<sup>II</sup><sub>2</sub>(<b>P</b><sub><b>Z</b></sub><b>MAT</b>)<sub>2</sub>](BF<sub>4</sub>)<sub>4</sub>∙MeOH∙2H<sub>2</sub>O (<b>1</b>∙MeOH∙2H<sub>2</sub>O) and [Fe<sup>II</sup><sub>2</sub>(<b>P</b><sub><b>Z</b></sub><b>MPT</b>)<sub>2</sub>](BF<sub>4</sub>)<sub>4</sub>∙3H<sub>2</sub>O (<b>2</b>∙3H<sub>2</sub>O), have been prepared. A structure determination at 100 K on <b>2</b>∙3.5MeCN confirmed that the ligands adopt the expected binding mode, providing all twelve donors to the two iron(II) centres and two <i>N</i><sup>1</sup>,<i>N</i><sup>2</sup>-triazole bridges between them. Both undergo gradual incomplete spin transitions: at room temperature <b>1</b>∙MeOH∙2H<sub>2</sub>O and <b>2</b>∙3H<sub>2</sub>O are approximately two-thirds to three-quarters [HS-HS], dropping to mostly ‘[HS-LS]’ at 50 K. The structure determination and Mössbauer spectroscopy of <b>2</b> qualitatively support this. These findings are consistent with the pendant pyrazines providing a somewhat higher field strength than the pendant pyridines do in the analogous <b>PMRT</b> complexes.</p
