An investigation of 1,4-dicyanotetrazine as a building block in molecule-based magnetic materials.

摘要

Organic ligands are important components in molecule-based magnets, as they allow for control over the physical and magnetic properties. Spin-carrying radical organic ligands, specifically, have been seen to enhance magnetic properties. Investigating reactions of 1,4-dicyanotetrazine, DCNT, an organic ligand capable of being reduced to a radical anion (-0.033 V vs. SCE), with spin carrier and paramagnetic building-blocks such as decamethylferrocene, vanadium hexacarbonyl, and tetrakis(dimethylamino)-ethylene have led to mixed results.;While the reaction of Fe(Cp*)2 with DCNT was expected to form 0-D chains of alternating [DCNT]•- and [FeCp*2] •+ that magnetically ordered, this was not the case as the room-temperature chiT value of 0.222 emu K/mol was significantly lower than the calculated spin-only value of 0.75 emu K/mol for a system of two S = 1/2 ions. However, as the infrared spectrum indicates reduced DCNT, another bonding motif may be occurring that could include the dimerization or trimerization of DCNT. The structure of [FeCp*2][DCNT] has not been elucidated and further investigation is needed.;Reaction of DCNT and V(CO)6 forms a black amorphous precipitate, similar to V[TCNE]x. Infrared spectra indicate reduced DCNT; however, the magnet data are inconclusive. TDAE and DCNT forms an electron transfer salt, in which DCNT is reduced and TDAE is oxidized to the 2+ charge. The magnetic data are also inconclusive.