Dinuclear Spin-Crossover Complexes Based on Tetradentate and Bridging Cyanocarbanion Ligands Eric Milin Sabrina Belaïd Véronique Patinec Smail Triki Guillaume Chastanet Mathieu Marchivie 10.1021/acs.inorgchem.6b01542.s001 https://acs.figshare.com/articles/journal_contribution/Dinuclear_Spin-Crossover_Complexes_Based_on_Tetradentate_and_Bridging_Cyanocarbanion_Ligands/3581535 Spin-crossover (SCO) Fe­(II) dinuclear complexes of formula [Fe<sub>2</sub>(tmpa)<sub>2</sub>(μ<sub>2</sub>-tcpd)<sub>2</sub>]·0.8­(CH<sub>3</sub>OH) (<b>1·MeOH</b>) and [Fe<sub>2</sub>(andmpa)<sub>2</sub>(μ<sub>2</sub>-tcpd)<sub>2</sub>]·2CH<sub>3</sub>OH (<b>2·MeOH</b>) (tmpa = tris­(2-pyridylmethyl)­amine, andmpa = bis­(2-pyridylmethyl)­aminomethyl)­aniline, (tcpd)<sup>2–</sup> = 2-dicyanomethylene-1,1,3,3-tetracyanopropanediide) have been synthesized and characterized by infrared spectroscopy, X-ray diffraction, and magnetic measurements. The crystal structure determinations of the two complexes (<b>1·MeOH</b> and <b>2·MeOH</b>) and the desolvated complex <b>1</b> (from <b>1·MeOH</b>) revealed a neutral centrosymmetrical dinuclear structure in which the (tcpd)<sup>2–</sup> cyanocarbanion acts as a double μ<sub>2</sub>-bridging ligand between two [FeL]<sup>2+</sup> (L = tmpa (<b>1</b>), andmpa (<b>2</b>)) units involving two free coordination sites in the <i>cis</i> configuration. Examination of the shortest intermolecular contacts in <b>1·MeOH</b> and <b>1</b> reveals no significant hydrogen bonding between the dinuclear units, while in <b>2·MeOH</b> these units are held together by significant hydrogen bonds between one of the uncoordinated nitrile groups and the anilate function, giving rise to 1D supramolecular structure. The three dinuclear complexes <b>1</b>, <b>2·MeOH</b>, and <b>2</b> exhibit SCO behaviors which have been evidenced by the thermal evolutions of the χ<sub>m</sub><i>T</i> product and by the average values of the six Fe–N distances for <b>1</b> and <b>2·MeOH</b>, that reveal a gradual conversion with transition temperatures (<i>T</i><sub>1/2</sub>) at ca. 352 K (<b>1</b>), 196 K (<b>2</b>), and 180 K (<b>2·MeOH</b>). For the solvated <b>1·MeOH</b>, the sharp SCO transition observed around 365 K was induced by the desolvatation process above 330 K during the magnetic measurements. 2016-08-15 18:48:42 OH Bridging Cyanocarbanion Ligands Spin-crossover Dinuclear Spin-Crossover Complexes 2 exhibit SCO behaviors χ m T product dinuclear complexes 1 1 D supramolecular structure crystal structure determinations tcpd uncoordinated nitrile groups Fe 2 CH MeOH centrosymmetrical dinuclear structure