Tunable Reduction of 2,4,6-Tri(4-pyridyl)-1,3,5-Triazine: From Radical Anion to Diradical Dianion to Radical Metal-Organic Framework.

The reduction of 2,4,6-tri(4-pyridyl)-1,3,5-triazine (TPT) with alkali metals resulted in four radical anion salts (1, 2, 4 and 5) and one diradical dianion salt (3). Single-crystal X-ray diffraction and electron paramagnetic resonance (EPR) spectroscopy reveal that 1 contains the monoradical anion TPT.- stacked in one-dimensional (1D) with K+ (18c6) and 2 can be viewed as a 1D magnetic chain of TPT.- , while 4 and 5 form radical metal-organic frameworks (RMOFs). 1D pore passages, with a diameter of 6.0 Å, containing solvent molecules were observed in 5. Variable-temperature EPR measurements show that 3 has an open-shell singlet ground state that can be excited to a triplet state, consistent with theoretical calculation. The work suggests that the direct reduction approach could lead to the formation of RMOFs.