No abstract

Aiming at the targeted construction of coordination polymer luminophores, the engineering of host-guest architectures with charge transfer based emissions is performed by utilizing the interactions between the electron-deficient 2,4,6-tri(pyridin-4-yl)-1,3,5-triazine (tpt) and electron-rich polycyclic aromatic hydrocarbons (PAHs) motifs as acceptors and donors, respectively. Through guest modulation of a prototype coordination polymer [Cd(tpt)(1,4-pda)(HO)]·(tpt)·(HO) (1) (1,4-Hpda = 1,4-phenylenediacetic acid), a series of coordination polymers with different PAHs as guests, [Cd(tpt)(1,4-pda)]·guest (2-5) (guest = triphenylene for 2, pyrene for 3, coronene for 4, and perylene for 5), are successfully fabricated. Distinct from 1, coordination polymers 2-5 reveal unique bilayer structures with PAHs interlayer and good stability, owing to the enhanced stacking interactions between tpt motifs and PAH guests. Moreover, their emissions cover a wide range of wavelength due to the effective guest to host charge transfer interactions between donor and acceptor motifs. Their readily tunable host-guest charge transfer based emissions make them good candidates as potential luminophores.

Owing to their rich porosity and structural diversity, metal–organic frameworks (MOFs) offer substantial advantages over other emission sources for the precise design and color regulation of white-light phosphors. However, achieving efficient white-light emission remains a considerable challenge. Herein, we report a strategy to achieve tunable and efficient white-light emission by regulating energy transfer in a multicomponent dye-loaded MOF. An anionic MOF NKU-114 featuring appropriate confined spaces is designed as a host to deliberately encapsulate three red-, green-, and blue-emissive dyes with adaptive spectral overlap, DSM, AF, and 9-AA, respectively, yielding the NKU-114@dyes composites. Integrating the suitable spectral overlap and efficient energy transfer between the dyes and the framework produced a white-light emission material containing the multicomponent dyes NKU-114@DSM/AF/9-AA. The obtained material has a broadband white emission with a high quantum yield (up to 42.07%) and nearly identical CIE coordinates of (0.34, 0.32), and the moderate correlated color temperature and color-rendering index value can reach up to 5101 K and 81, respectively, suggesting the potential of the multicomponent dye-loaded MOF for white-light-emitting phosphors with good color quality.