Harnessing Bismuth Coordination Chemistry to Achieve Bright, Long-Lived Organic Phosphorescence

A new bismuth(III)-organic compound, Hphen[Bi₂(HPDC)₂(PDC)₂(NO₃)]·4H₂O (Bi-1; PDC = 2,6-pyridinedicarboxylate and phen = 1,10-phenanthroline), was synthesized, and the structure was determined by single-crystal X-ray diffraction. The compound was found to display bright-blue-green phosphorescence in the solid state under UV irradiation, with a luminescent lifetime of 1.776 ms at room temperature. The room temperature and low-temperature (77 K) emission spectra exhibited the vibronic structure characteristic of Hphen phosphorescence. Time-dependent density functional theory studies showed that the excitation pathway arises from an energy transfer from the dimeric structural unit to Hphen, with participation from a nine-coordinate Bi center. The triplet state of Hphen is believed to be stabilized via supramolecular interactions, which, when coupled with the heavy-atom effect induced by Bi, leads to the observed long-lived luminescence. The compound displayed a solid-state quantum yield of over 27%. To the best of our knowledge, this is the first such compound to exhibit phenanthrolinium phosphorescence with such long-lived, room temperature lifetimes in the solid state. To further elucidate the energy-transfer mechanism, Ln³⁺ (Ln = Eu, Tb, Sm) ions were successfully doped into the parent compound, and the resulting materials exhibited dual emission from Hphen and Ln, promoting tunability of the emission color.

Photophysical properties of Ag, Zn and Cd - N-(4-pyridylmethyl)-1,8-naphthalimide complexes: influences of π-stacking and C–H⋯O interactions

In solution ligand and complexes show similiar fluorescence emission whereas emission in solid samples are distinguishable.

Two luminescent transition-metal–organic frameworks with a predesigned ligand as highly sensitive and selective iron(iii) sensors

The water-stable imidazole dicarboxylated-based MOFs are excellent luminescent probes for the Fe³⁺ ion in an aqueous solution.

A microporous cationic metal–organic framework for the efficient removal of dichromate and the selective adsorption of dyes from water

A microporous anionic metal–organic framework has been synthesized, which can be used as the effective adsorbent to methyl orange and Cr₂O₇²⁻ from aqueous solutions.

New complexes constructed from in situ nitration of (1H-tetrazol-5-yl)phenol: synthesis, structures and properties

New complexes based on three precursors via in situ nitration have been prepared. Moreover, the solid state UV-vis spectra and band gap energy of those complexes were investigated, and the luminescent properties (1–3, 7 and 8) and magnetic properties (3–6 and 9) were also discussed.