Photochromic Dy-Phosphonate Assembled by a Pyridine Derivative: Synthesis, Structure, and Light-Enhanced Room-Temperature Phosphorescence

Abstract

Hydroxyethylidene diphosphonate (HEDP) and tris(4pyridyl)amine (TPA) are employed to assist the preparation of a Dy(III)-phosphonate in this work, namely, {[Dy 2 (H 2 -HEDP) 4 ] 3 •2(H 3 -TPA)•2(H 4 -HEDP)•xsolvent} (1). The compound features the anionic one-dimensional chain structure templated by the cationic H 3 -TPA and uncoordinated H 4 -HEDP molecules. Through the hydrogen bonds between the guest cations and host Dy(III)-phosphonate skeletons, a supramolecular architecture is finally constructed, displaying photochromism and room-temperature phosphorescence (RTP) behaviors. Interestingly, through the protonation of TPA molecules, the radicals generated after photochromism still remain a highly stable character, accomplishing an extremely long-lived state of charge separation. Moreover, the photogenerated radicals can greatly prompt the RTP performance of compound 1, which offers a promising strategy for the construction of tunable optical materials.

Photo‐Controllable Ultralong Room‐Temperature Phosphorescence: State of the Art

“…These results have been proved in several pyridine-based MOCs as reported by our group, [20] Zheng's group [21][22][23][24][25] and Wang's group. [26,27] As a typical example, our group reported dynamical control of ultralong RTP based on the (Zn-(HCOO) 2 (4,4'-bipy) (ZnÀ BP) compound, in which 4,4'-bipy was chosen as the electrondeficient ligand and formic acid acted as the electron-rich ligand (Figure 1a). [20] Additionally, the multiblock core-shell compounds heterostructures presenting space-resolved PC and RTP were also synthesized.…”

Photochromism and Photomagnetism in Two Ni(II) Complexes Based on a Photoactive 2,4,6-Tris-2-Pyridyl-1,3,5-Triazine Ligand

“…For the formation of ET photochromic complexes, the incorporation of suitable electron donors (carboxylate, , phosphate/phosphonate, − halogens, , and polyoxometalates − ) and electron acceptors (pyridine, − imidazole, etc.) are regarded as a favorable approach to accomplish the photoinduced ET coloration.…”